Multi-level Ecology - Masters Thesis

Multi-level Ecology Open Space System for High Density Cities

Architectural Association School of Architecture

Master of Architecture, Emergent Technologies and Design 2018-2020 Elif Erdine Michael Weinstock Alican Sungur Antiopi Koronaki George Geronimidis

Multi-level Ecology Open Space System for High Density Cities

MArch.

Archit Mathur Yukie Takasu

MSc.

Fun Yuen

ARCHITECTURAL ASSOCIATION SCHOOL OF ARCHITECTURE GRADUATE SCHOOL Programmes

Programme:

Emergent Technologies and Design

YEAR:

2018-20

COURSE TITLE:

MArch. Dissertation

DISSERTATION TITLE:

Multi-level Ecology

STUDENT NAMES:

DECLARATION:

Archit Mathur (MArch.), Yukie Takasu (MArch.), Fun Yuen (MSc.)

“We certify that this piece of work is entirely our own and that any quotation or paraphrase from the published or unpublished work of others is duly acknowledged.”

SIGNATURES OF STUDENTS:

(Archit Mathur)

DATE:

10 January, 2020

(Yukie Takasu)

ACKNOWLEDGEMENTS We express our sincere gratitude to Michael Weinstock and Elif Erdine for their guidance in this project and during our time at the Architectural Association.

We would also like to express our gratitude to Alican Sungur, Antiopi Koronaki and George Jernomidis for their constructive criticism and insightful suggestions, both during the formation and development of the dissertation.

We would like to acknowledge the contribution of our fellow teammate Fun Yuen and thank her for her support throughout the project.

Finally, we would like to thank our family and friends for their love, support and encouragement in the course of this dissertation and throughout our study at the Emergent Technologies and Design programme.

ABSTRACT Multi-level Ecology is an exploration to develop a network of multilevelled open spaces in high-density urban environments. The lack of public spaces in contemporary cities is a pressing concern as it correlates to physical and mental illnesses and social isolation. An alternate circulation system at higher levels is proposed to enhance urban connections where the population density increases vertically.

The research aims to incorporate more than the provision of spaces, by enhancing programmatic variation, where once isolated institutions - residential, commercial, office, leisure, now overlap through these spaces, creating multi-layered opportunities in the urban area. Exploring varying sets of urban conditions, this research proposes an integrated response that generates spatially diverse public spaces.

The work is contextualized in the urban area of Sai Ying Pun located in the city of Hong Kong. The high-rise high-density urban fabric of the city is characteristic of the issues of social deprivation.

Additionally, the research deals with seasonal climatic conditions and local hydrological problems of self sustainability and flooding that are pertinent to Hong Kong.

A multi-scalar approach incorporated in addressing the problem at the urban as well as the local scale establishes the need to accommodate a layered network of recreation, culture and wellness.

TABLE OF CONTENTS

1. Introduction............................................13

5. Design Development...............................117 Experiments Overview

2. Domain...................................................19

Global Scale

High Density Cities

Open space system elements

Hong Kong

Test Experiment I -Open Space Distribution

High Rise Living

Test Experiment II -Network Connection

Open Space

Integration Experiment

Urban Greenery

Programmatic Distribution

Climate

Local Scale

Cluster Selection

Case studies

Water Storage

Local Area Zoning

Conclusion

Planting Distribution

Research Question 6. Design Proposal.....................................231 3. Method...................................................53

Space Evaluation

Overview

Design Translation

Design Method Design Analysis

7. Conclusion.............................................253

Network Analysis

System Refinements Next Step

4. Research Development..........................61 Sai Ying Pun, Site

8. References............................................257

Topography

Bibliography

Transportation Network

Image References

Existing Open Spaces Evaluation

Programme and Building Type

Sunlight Hours and Wind Direction

Storm Water Discharge System

Conclusion Hydrological System

Irrigation Estimation

Rain water harvest system

Planting Strategy

Plant Research

Species Study Structural Consideration Layout Strategy

9. Appendix............................................267

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1 INTRODUCTION

13

14

Introduction | Multi-level Ecology

INTRODUCTION Hong Kong was planned in the early 1900s with the land requirement assessments of the time. This did not account for the post industrialization boom in population.

The rapid densification in the early 1900s coupled with inefficient urban planning with a lack of foresight has deteriorated the quality of life of the inhabitants of Hong Kong.

As the focus of planning is predominantly on satisfying occupancy, Hong Kong faces an acute lack of open space. The open space deficit has stemmed into both physical and mental well-being concerns. Open spaces act as places for interaction, the lack of which leads to a considerable increase in cases of social isolation and mental illnesses.

Inadequate connectivity of spaces is also a shortcoming of the planning. Being limited to ground level does not work in Hong Kong as it is counterproductive and simply unpleasant to be bound to building cores. The built density calls for a three-dimensional network system.

To achieve this system, we carry out our experiments in the area of Sai Ying Pun in Hong Kong. This urban patch comprises of the key issues that we want to address.

Being in the old district, Sai Ying Pun is packed with pencil towers and faces an acute deficiency of open spaces.

connections and create sustainable green social spaces of interest, by conducting experiments on this urban patch. These spaces will act as the new social hotspots and will be deeply integrated with the existing urban fabric.

We understand that by considerably increasing the amount of green spaces, there will be a requirement of a large amount of water to maintain these spaces. We will also propose a rainwater harvesting strategy by creating a potential for the site to self-sustain its water needs.

Public gathering spaces allow for social mixing, civic participation and recreation, which is not achieved by only the provision of space. In order to develop spaces of interaction and social mixing, the provided areas need to incorporate programmatic variation as well as inter-institutional integration, with smooth transitioning spaces from programme-to-programme while offering an array of activities that promote people to occupy them.

This research will conclude with a result of an urban patch that has transitioned from isolated point blocks that can only be associated with each other via ground level connections, to an integrated, three-dimensional, ecological urban fabric that has open spaces which have the potential to support diversified activities and sustain social interaction.

The topography is a major challenge due to its steep slope, and climatic conditions add to the unfavourable pedestrian conditions. Flash floods during peak rainfall months further contribute to the challenge. Sai Ying Pun, like most districts in Hong Kong, does not subscribe to local rainwater treatment and storage.

We aim to explore the untapped strategies of multi-level

15

16

Introduction | Multi-level Ecology

Key Interpretations Multi-level This project aims to transform high density cities from a monotonous urban fabric to an engaging multi-layered environment by achieving programmatic variation at multiple scales. It is not only ‘Multi-level’ in its explicit sense of level differences, but also multi-level in its multilayered approach with multiple environmental, social and programmatic factors driving the design.

The project addresses multiple institutions that form the core fundamental logic of our modern cities such as residential communities, places of work, leisure spaces and spaces for social integration and association.

Ecology Multi-level Ecology recognizes the necessity of the radical reorganization of the sprawling urban landscape into dense, integrated, three-dimensional cities in order to support the diversified activities that sustain human culture and environmental balance.

This design research is the fusion of architecture with ecology, a comprehensive urban perspective. In nature, as organisms evolve, they increase in complexity and become a more compact system. A city should similarly evolve, functioning as a living system co-dependent on its constituent institutions.

Responding to energy, rainwater conservation, solar radiation, plantation and socio-environmental factors, Multi-level Ecology stitches together diverse ecosystems and distinct cultural institutions, connecting north to south and the centre to the periphery.

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18

2 Domain

19

[DOMAIN]

High density high rise living

Problems and potential

Livability

Open space

Urban greenery

Hong Kong Ambition and Climate

Water Shortage

Case Studies

Singapore green social housing

Hong Kong elevated walkway system

High Line, New York

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Research Question

Domain | Multi-level Ecology

OVERVIEW The chapter commences with a discussion on high-density cities, identifying the living conditions and elaborating on the problems of such cities. We will also establish the scope of the project by focussing on aspects that can be improved.

Subsequently, the study will be narrowed down to the high-density city of Hong Kong, conducting in-depth research into how the city adapts and evolves in response to the continuous and rapid densification and land shortage. The potential to drive Hong Kong towards self-sustaining its water needs will also be investigated.

As this study hinges on theoretical concepts of spatial quality, urban livability in our context will be defined. The importance of spatial elements that directly affect the livability of an area such as green open spaces and connectivity drivers will be explored.

Precedent studies will provide us with practical insights and demonstrate the extent to which these spatial elements are currently being utilized.

Consequently, the domain chapter will conclude by summarizing learnings from the studies, explaining the precise focus of the design project, informing the research question based on improving the livability of a high-density city without needing to wipe out the existing urban built structures.

21

22

Domain | Multi-level Ecology

Hong Kong

Mexico City

London

Population Density

Population Density

Population Density

6,766 people/km²

9,800

people/km²

4,542 people/km²

HIGH DENSITY CITIES Problems and potentials The fundamental concept of density reflects the population per unit area. Density is also strongly related to the interactions between space and the people using the space. The perceptual limitations of most high-density cities relate to a negative peoplespace interaction.

It is commonly stated that cities with higher densities are more sustainable than low-density cities.

Much contemporary urban planning, particularly in North America, the UK and Australia cope with urban sprawl systematically by developing sufficient infrastructure preemptively before the inflow of people. However, a region with a perfectly functional model that copes with high density is yet to be seen.

Fig.1. (prev. page) High Density Hong Kong Fig.2. (top) Density of Hong Kong, Mexico City and London

No two high-density cities have the same set of problems, but certain complications are identified as a trend common to most high-density cities.

High-density cities’ residents cope with concrete environments packed with high-rise offices and residential buildings, acutely limited urban open space, a substantial urban heat island effect and high concentrations of roadside pollution that fail to

disseminate from poorly ventilated street canyons.

These factors, combined with crowding at the street level and in public areas have a detrimental impact on the livability of that area.

We must differentiate between ‘density’ and ‘crowding’. While ‘density’ is used to refer to the physical limitation of space, ‘crowding’ is the genuine psychological perception of the limitation of space (Ying-Keung Chan 1999). Social pathology is caused due to stress and social conflict of crowding, whereas high density may not necessarily lead to a perception of crowding or stress. Hong Kong, despite its density, can have high standards of liveability. It is a widespread belief that high-rise living is the driving factor for most of the negatives that relate to highdensity cities.

For the design and planning of high-density cities, the relationship between the dwelling buildings and the surrounding spaces in residential areas must be considered, not only from the physical aspect but also from the social perspective.

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HONG KONG OVERVIEW Understanding the context Hong Kong was planned during the early 20th Century. Since then, the city has gradually grown to transform into a vertical city, due to various factors, such as a rapid population explosion, topographical limitations of hilly and coastal terrain, economic development and the pursuit of sustainable living for its populace (Stephen S. Y. Lau, Qianning Zhang 2015, 117-118).

Hyper-density, multifunctional and integrated development, land preservation, vertical mixeduse, and large vertical scale uniquely constitute the main characteristics of Hong Kong as a vertical city, compared to other global high-density cities.

With a population of over 7.4 million people in an urban land area of just 120 km², Hong Kong is one of the most densely populated places in the world. The city has evolved into the quintessential high-density small-footprint city as it consists of several large mountainous islands, leaving only 30% of the city sufficiently flat to accommodate built form, the result of which is extensive land reclamation that restrains city growth (Barrie Shelton, Justyna Karakiewicz,

24

Thomas Kvan 2011, 4-5). Additionally, more than 75% of this land comprises non-built-up areas (protected area), implying that the entire population must fit on the remaining 24% of the land.

Due to this, the people have no option but to adapt to an overcrowded living environment with depleting open space, less greenery, a lack of privacy and a high occurrence of noise disturbance at the community level. As a result, Hong Kong suffers in the world rankings of livable cities (Stephen S. Y. Lau, Qianning Zhang 2015, 117-118).

Fig.3. High density city and its preserved area, Hong Kong Fig.4. Map of Hong Kong

Domain | Multi-level Ecology

Land Supply of Hong Kong

Density

Build-able Area 76% reserved land 24%

build-able land

Population (2019)

7.496 million

Total Land Area

1,111 km²

Total Build-able

270 km²

Population Density (Build-able area)

27,763 people/km²

Residential Density

95,000 people/km²

Reclaimed Land by Area 18%

non-reclaimed land

6%

reclaimed land

Land Use by Area 6.8%

residential

2.5%

open space

14.7%

other

Population of Hong Kong (2010-2028) 8.2

Population (million)

8.0 7.8 7.6 7.4 7.2 7.0 6.8 6.6 2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

Year

25

build-able land reserved land

HIGH RISE LIVING Pros and cons of high rise living and the evolution of buildings in Hong Kong Living in a highrise building can come with many advantages such as the location, security, in-house amenities, administered maintenance and the view.

It is widely accepted as the ‘efficient’ way of living in terms of space, built quality and resource proximity.

not irreparable. Steps can be taken in planning and design to increase the quality of living in these megastructures.

Though highrise living has its advantages, certain significant limitations can not be ignored. In order to achieve occupancy, high rises are designed to cut down on space as much as possible, reducing the dwelling area and common open areas within buildings which are essential for community living.

Open spaces in highrises promote movement, interaction and create a potential for greenery, lack of access to which, may result in social alienation of a person.

Social deprivation and fragmentation unquestionably play a role in the general mental health of the inhabitants of any given area. The continued densifications of the cities may result in more people shifting to this way of living, further contributing to the high-density and the shortage of space. Although the cons of highrise living are significant, they are

26

Fig.5. (left) A residential precinct in Sha Tin, New Territories, Hong Kong, built in 1970s.

Fig.6. (right) An example of a pencil tower, Hong Kong, built in 2010s.

Domain | Multi-level Ecology

Shop house (1920-1940)

Concrete cantilevered type (1950s)

Sloped, set-back type (1970s)

Block type (1970s)

Podium + tower (1980s)

Hyper podium + tower (1990s)

Podium + Super high rise (2010-present)

Shop house (1920-1940)

Concrete cantilevered type (1950s)

Sloped, set-back type (1970s)

Block type (1970s)

Podium + tower (1980s)

Hyper podium + tower (1990s)

Podium + Super high rise (2010-present)

Shop house

Concrete Sloped, cantilevered type set-back type

(1920-1940)

(1950s)

(1970s)

Block type (1970s)

Podium + tower (1980s)

Hyper podium + Tower (1990s)

Hyper podium + Super high rise (2010 - present)

1920-1940

1950s

1960s

1970s

1980s

1990s

2000-2010

1920-1940

1950s

1960s

1970s

1980s

1990s

2000-2010

Total Population

2M

3M

3.8M

In the case of Hong Kong, the small sites that once used to have lowrise brick houses, today have highrises of the same prior footprint. Because of the lack of policy of land reclamation from private landowners, private developers only aimed at redeveloping the small sites for highest possible towers to maximize occupancy and profit, resulting in the fragmented “pencil” or “toothpick” development in the old districts (Chan, K. R., Chow, T. A., Lee, N. K..

2015).

In the 1980s, to accommodate the rising population, the government released policy to reclaim the land that was utilized to build private mass housing estates. Contrary to the old district renewal, these estates built on the reclaimed flat land were planned with inclusive facilities and were considered to offer a higher quality of life.

4.9M

5.8M

7M

programmes. This building type soon became ubiquitous and to this day, is the most common configuration seen in Hong Kong.

The podium and tower typology impacts the city in ways that the previous typologies did not. A podium with a large site coverage not only obstructs most of the wind to pedestrians but also traps air between podiums, affecting air quality (Edward NG, 2003).

Additionally, the podium also blocks sunlight from reaching the pedestrian level.

The built morphology of Hong Kong adapts and repeatedly evolves to cater to the needs of the time.

As the existing urban fabric is causing several socioenvironmental complications, there is a need for the built structure to evolve yet again.

During the early 1990s, the 15m full plot coverage bye-law was revolutionary to Hong Kong’s architecture and planning as it gave rise to the mixed-use tower + podium morphology; in which the podiums were developed to have commercial

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URBAN OPEN SPACE Importance of open spaces in urban environments Open spaces are open pieces of land that have no buildings or built structures and are accessible to the public. These can include parks, community gardens, school-yards, playgrounds, public seating areas, public plazas and vacant lots. It provides recreational areas for its users and helps enhance the aesthetic and environmental quality of neighbourhoods.

The quality and quantity of open spaces are vital in determining the livability of an open area.

According to the World Health Organization (WHO), an urban open space brings out numerous social and ecological advantages. These spaces encourage exercise in both grown-ups and children, promoting better physical wellbeing.

Living within walking distance from an open space can reduce health imbalances, improve wellbeing, and aid in the treatment of mental illness. Physical activity in a natural environment can help mild remedy depression and reduce physiological stress indicators. Additionally, these spaces encourage interaction, social equality and a sense of community.

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While a larger quantity of urban open spaces is necessary, there is a need for an increase in quality as well. In the context of Hong Kong, many pocket parks are not well designed. These are mainly dark spaces that lack seating and sufficient air circulation. These spaces need to be designed as inviting recreational spaces and must account for pleasurable user experience, irrespective of its size.

Since livability refers to the quality of life in a human living environment, this notion is concerned with optimizing the integrity and the performance of human life (Ellis and Roberts, 2016 Hagerty et al., 2001). An area’s livability can be evaluated in a wide range of contexts within the field of planning such as transportation, community development, resilience, spatial comfort and circulation.

The focus of this study will lie on the physical and mental wellbeing of citizens by introducing and integrating environmentally sensitive green open spaces within the urban fabric.

Fig.7. A pocket park below the highway, Hong Kong

Domain | Multi-level Ecology

Fig.8. Open space on the platform level within a public estate, Hong Kong

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URBAN GREENERY Importance of greenery in urban environments Green spaces are critical elements contributing to the citizens’ health and the sustainability of the city.

Living close to green open spaces assists individuals’ capability to mitigate stress and is related to a lower rate of depression and anxiety.

The environmental and ecological benefits of urban greenery include isolating air pollution particles and greenhouse gasses, facilitating wind circulation in areas with high built density, moderating the urban heat island effect, decreasing storm-water runoff and reducing noise pollution.

Biodiversity is used as a means of measuring how healthy a particular ecosystem is. A healthy ecosystem is capable of sustaining a wide variety of life. Urban biodiversity of a region contributes to creating breathable air to the supply of clean water, even seemingly insignificant insects provide vital ecological services including pest control, pollination, and wildlife nutrition — conservation of biodiversity assists in maintaining ecosystem services that are essential for human life to persist.

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With the increase of carbon emissions and nonnatural materials, it can be difficult for local flora and fauna to thrive. As 51% of the total population of the world now lives in cities, there is a vast carbon footprint being created. One way to offset this carbon footprint is to support a healthy environment by increasing its biodiversity.

Urban environments can be developed to promote the integration of biodiversity with the introduction to green infrastructure. Using local plant species in green infrastructure such as sky gardens, green walls and green roofs can ensure that the local biodiversity in an urban area thrives.

Domain | Multi-level Ecology

Fig.9. Sit-out area with greenery in a high density area, Hong Kong

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CLIMATE Environmental considerations for design Subtropical Hong Kong has four distinct seasons warm and humid spring, hot and rainy summer, sunny autumn and pleasant-dry winter.

The comfortable range of outdoor humidity corresponding to Hong Kong temperatures lies between 30-60%. The humidity, however, is always above that. The highest humidity is generally recorded in April and May at 83% while the lowest is in December at 69%.

Summers The peak summer months are between June and August in Hong Kong, coupled with frequent typhoons.

June has the highest average rainfall, and there is a constant threat of summer showers, typhoons, and thunderstorms. Temperatures usually exceed 30°C during the day. The continuous scorching sun and low breeze result in extreme heat indices, which usually lasts till around July and August. Nights are also warm with an average temperature of 26°C. Winters Winter in Hong Kong by local standards is generally cold with temperatures ranging from 15°C-19°C. Winter usually starts in December and becomes cloudier towards February. The coldest month is January, and the temperature reaches 14°C-18°C. The winter months receive the least amount of precipitation. During these months, due to the lack of water storage systems, Hong Kong imports all its water.

Typhoon and monsoon In September 2017, Hong Kong experienced typhoon Manghut and faced the highest wind speeds recorded in more than a decade.

These high winds take down trees, smash windows and even blow away roofs of smaller accommodations.

Sudden cloud-bursts almost always accompany typhoons. These instant heavy rains lay waste to the

32

drainage system and result in flash floods.

Wind Present in a subtropical hot and humid climate, the wind velocity is dampened due to the perennial high humidity. The humidity, coupled with the building density, further minimizes the wind velocity. Housing estates built in the 1990s were so tall and dense, they were termed as “wall buildings” because they cut off air circulation in the neighbourhoods around them, trapping air pollution and bumping up summertime temperatures by several degrees.

The prevailing wind blows from West to East in Hong Kong. This prevailing wind direction remains constant all year except for three months in the summer. From June to August, the prevailing wind flows from SouthWest.

Domain | Multi-level Ecology

100

40

30

75

32°C

50

20

10

14°C

25

Relative humidity (%)

Temperature (°C)

82%

0

0

Record high temperature Record low temperature Relative humidity

25

452mm

400

20

300

15

200

10

100

5

0

0

Rainy days (d)

Average rainfall (mm)

500

Rainy day (daily rainfall ≥ 0.1mm) Total rainfall

(top) Maximum and minimum monthly temperature and maximum humidity throughout the year in Hong Kong (middle) Average rainfall and number of rainy days in Hong Kong

Number of typhoons

10 8 6 4 2 0 2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

118-149 km/h

(bottom) Number of typhoons and speed in 10 years in Hong Kong

150-184 km/h 185 km/h or more

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WATER SUPPLY AND SHORTAGE Shortage of fresh water supply With no natural lakes, large rivers or underground water, Hong Kong faces the challenge of securing a stable and adequate supply of water to meet its development needs. In the past decade, Hong Kong’s annual water consumption was over 920 million cubic metres. The annual net yield, covering only 20% to 30% of the total consumption, was inadequate to meet the huge demand.

Currently, Hong Kong does not reuse rainwater locally, missing the opportunity for building a selfsustainable system in individual areas .

The gathering of rainwater in an appropriate way can be a permanent resolution to the water crisis in Hong Kong. This basic strategy is particularly workable in Hong Kong where there is a substantial downpour, and both the groundwater supply and surface water resources are inadequate. This is particularly applicable in hilly areas where the channelling of water from higher to lower ground is especially effective without the direct use of pumps.

Hong Kong sees low rainfall during winter and extremely heavy rainfall during summer . With an

34

effective local rainwater harvesting system, the area may have the potential to be self-sufficient even during winter.

Systematic rainwater harvesting can help in irrigation with the minimum use of technology and is, therefore, cost-effective. This straightforward technique can help irrigate plants in green open spaces even during the dry months and can be utilized to revitalize the ground level water and improve its quality. It additionally creates a sense of social responsibility and mindfulness about the environment.

The grey water is also a relatively untapped resource in Hong Kong. The grey water from households is channelled into the storm water drains and ejected.

Bridging this enormous gap between the local yield and the local demand can be attempted by a new local conservation strategy.

Fig.10. Empty reservoirs in Hong Kong

Domain | Multi-level Ecology 8.2

Population (million)

8.0 7.8 7.6 7.4 7.2 7.0 6.8 6.6 2010

8.2

2012

2014

2016

2018

8.0 Population (million)

2020

2022

2024

2026

2028

Year

7.8 7.6 7.4 7.2 7.0 6.8 6.6 2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

Year

25.1%

Service Trades

6.2%

Industrail

8.2%

Flushing

4.4%

600 Government Establishments

1500

2%

Construction

400

1000

200

500

54.1%

Domestic

25.1%

Service Trades

6.2%

Industrial Industrail

8.2%

Flushing

4.4%

Government Establishments

2%

Construction

1200

3000

1000

2500

800

2000

0 2012

1500

400

1000

200

500

0 2011

2012

3000 2013 2014

Annual water consumption Annual rainfall

600

Water imported from China Water from Hong Kong’ s catchment

400

2000 1500 1000 500

200 0

2016

2015 2016 Water from China

Pitched roof

0.8 0.7

0 2012 2013 2014 Water Consump�on

2015

Asphalt surfaced area

0

0.9 2016

2015

Run-off Coefficient

800

2014

Annual rainfall

600

2010

2013

3000

2500

2011

2011

Annual water consumption

1000

2010

2010

800

2009

2009

0 2009

Water imported from China 2500 Water from Hong Kong’s s catchment 2000

1000

Annual Rainfall (mm)

Domestic

Annual Water Consumption (million m³)

54.1%

Annual Rainfall (mm)

Annual Water Consumption (million m³)

1200

1200

Annual fresh water consumption, water supply and rainfall

Annual Rainfall (mm)

Annual Water Consumption (million m³)

Annual Fresh Water Consumption 2013 by sectors in million m 3

Hong Kongs Catchment

Block pavement

Moss

Concrete flat roof

Herbs

0.6

Lawns

0.5

Shrubs

0.4

Sedum

0.3

Sedum/ gass Grass

0.2

Trees

0.1 Annual water consumption Annual rainfall

0 0

100

200

300

400

500

600

700

Substrate thickness (mm)

Water imported from China Water from Hong Kong’ s catchment

Surface with vegetation Hard surface

35

36

Domain | Multi-level Ecology

CASE STUDIES

37

MULTI-LEVEL PUBLIC SPACES IN SINGAPORE’S PUBLIC HOUSING Case study of Skyville and Pinnacle@Duxton This case study demonstrates what happens when public spaces with specific priority are located on high levels within the building structure and their impact on privacy. Pinnacle@Duxton and Skyville at Dawson were chosen as case studies, as the estates are in a similar context of Singapore and because they have integrated sky gardens within their highrise, high-density housing typology. These projects are situated in a mixed public and private area in high-density high-rise buildings, challenging the norms of high-rise development by demonstrating that high-density towers can also be high amenity by clearly establishing community living and sustainability as their central themes.

Open spaces that are present on the ground level in generic projects are present at every five stories in Skyville and two levels in the Pinnacle. These green open spaces have increased accessibility and usage compared to projects with only ground floor access.

The open spaces promote a sense of community and promote social interaction.

The multi-level social spaces in Skyville are strongly influenced by the structure of the building and

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are designed to compose many small pockets of greenery. This greenery does not only serve as landscape elements but also facilitates privacy, acting as barriers between public spaces and private accommodations. The Sky Garden on the roof is the most frequently used space by the residents as it provides excellent city views and is accessible to the public. On the other hand, the Pinnacle provides a broader array of amenities in the two levels of sky gardens including jogging tracks, playgrounds and sky gyms with well-shaded, open and breezy rest areas.

The higher accessibility of sky gardens at the Pinnacle may have a negative impact on its residents.

Sky gardens isolated from the residential units may be preferred due to concerns over privacy and the related issues of noise and littering. The accessibility is not a pressing concern at Skyville as the public spaces programme is sedentary, which limits the use of the spaces (Dr Swinal, Na Hsi-En, 2017). A bioswale present on-site at Skyville treats site storm water then discharges it into the city’s drainage system. No such sustainability measure is taken at the Pinnacle.

Fig.11. (next page top left) Exterior of The Pinnacle@ Duxton in Dawson, Singapore Fig.12. (next page bottom left) Sky garden of The pinnacle@Duxton in

Dawson, Singapore Fig.13. (next page top right) Exterior of SkyVille in

Dawson, Singapore Fig.14. (next page bottom right) Sky garden of SkyVille in Dawson,

Singapore

Domain | Multi-level Ecology

The Pinnacle @ Duxton

SkyVille

Location Architects

Location Architects Client

Dawson, Singapore WOHA Housing & Development Board, Singapore

Year

2015

Client Year

Dawson, Singapore ARC Studio Architecture + Urbanism Housing & Development Board, Singapore 2010

39

o Community entre

The two projects also show that a balance of sustainability, communal living and occupancy can Public Space Evolution In High-Density Living In Singapore 175 be achieved that may be in favour of the city as well as the residents.

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Staircase Stop Community Center (Enclosed)

Urban Street

Elevator Stop Multi-Functional Pavilion

Elevator Shaft

Void Deck Resident Corner

Stairwell

Commecial Unit Sitting Pavilion

Jogging Track

Multi-Storey Car park

Uncovered Pedestrian Networks

Community Garden

Open Green Space

Covered Pedestrian Networks

Hard Court

Fitness Corner

To Community Centre

BLK 1D

To Bus Stops and Overhead Bridge

BLK 1G

BLK 1F

Floor 2

BLK 1E

Floor 3

BLK 1C

Public Space Evolution In High-Density Living In Singapore

175

Floor 51

To Neil Road

Floor 1

To Cantonment Road

Access Diagram

In order to maximize the sky garden’s potential as a well-utilized leisure space, a variety of amenities need to be incorporated and that these adjustments to the programme should ideally be complemented with favourable design characteristics, such as the provision of adequate shelter, a variety of scales, and ease of access. Direct visual connectivity between residential units and the sky gardens should be avoided to maintain occupants’ privacy. The degree of regulation of the gardens also needs to be managed to avoid the unreasonable limitation of the activities available to residents (Dr Swinal, Na Hsi-En, 2017).

BLK 1A

In high-density cities, the residue space left after site development can no longer sustain the open space requirements of the populous. Skyville exhibits that private developments can be utilized to create open spaces for its residents as well as the public.

BLK 1B

Conclusion

Playground

Residential Unit

Floor 51 Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor 28 29 30 33 35 31 32 34 36 37 38 41 43 39 40 42 44 48 45 46 49 47 50 Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor 20 4 5 6 9 11 12 15 16 18 7 8 10 13 14 17 19 21 22 25 23 24 26

Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor 28 29 30 33 35 31 32 34 36 37 38 41 43 39 40 42 44 48 45 46 49 47 50

Basement

Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor Floor 20 4 5 6 9 11 12 15 16 18 7 8 10 13 14 17 19 21 22 25 23 24 26

Playground

Hard Court

Residential Unit

Fitness Corner

Community Garden

Covered Pedestrian Networks

Open Green Space

Multi-Storey Car park

Uncovered Pedestrian Networks

Sitting Pavilion

Commecial Unit

Jogging Track

Resident Corner

Void Deck

Stairwell

Multi-Functional Pavilion

Elevator Stop

Elevator Shaft

Community Center (Enclosed)

Staircase Stop

Urban Street

Domain | Multi-level Ecology

Sky garden

Sky garden

Podium park

Rooftop garden

Sky garden

Sky garden

Fig.15. (prev. page top) Access diagram of The Pinnacle@Duxton Fig.16. (top) Section through The Pinnacle@ Duxton showing green spaces at various levels Fig.17. (bottom) Section through SkyVille showing green spaces at various levels

Sky garden

Link Bridge Podium Park

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ELEVATED WALKWAY SYSTEM IN CENTRAL, HONG KONG Case study of pedestrian connections, Central, Hong Kong Hong Kong’s central business district, also known as Central, is connected with an effective pedestrian network, the development of which began in the 1960s.

The elevated pedestrian network was initially created to channel internal circulation within commercial centres when the city was undergoing rapid growth in the 1960s and 1970s. This pedestrian network prioritised pedestrian movement within Central’s commercial zone to encourage a consumer-oriented economy.

As the number of domestic buildings continued to grow, the city was unable to provide adequate public communication at ground level. Thus a framework of pedestrian planning was released that called for the provision of a three-dimensional pedestrian network comprising of multi-level links by elevated walkways and escalators, facilitating pedestrians to be able to move freely over vast areas segregated from vehicular traffic (Zheng Tan, Charlie Q., 2016).

Central’s Transit stations, open spaces, malls, parking structures, and streets are all independently operated urban systems that were envisioned to connect to and comply with each other at different levels through tunnels, ramps, escalators, conveyance belts, and lifts.

One of the main drivers for this was to address the two main problems of the traffic situation in

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Central. Firstly, the limited widths of walkways were challenged to accommodate pedestrians during peak hours. Secondly, the limited access and the social hierarchy limited the connectivity with the streets below.

The Central Mid-level Escalator is a prime example of how a creative solution of inaccessibility up the steep slopes resulted in the construction of escalators that have today become tourist attractions and iconic to Hong Kong. It provides the fastest way to reach the highest elevations of the urbanised area, which takes only 20 minutes. In contrast, it takes 27 minutes for a taxi (Wang Han, 2018).

In the southwest part of the walkway system, there are mainly short span sky bridges connecting private commercial buildings. These are enclosed, protecting pedestrians from the weather elements and providing them with a continuous and comfortable climate-controlled space (Wang Han, 2018). While an array of covered pathways and escalators provide access to areas that are at a higher elevation.

Furthermore, the usage of the proposed open spaces is designed to be dynamic. In the current scenario, during the weekends, the underprivileged gather in these areas to utilise them as a shaded communal space.

Fig.18. (top) Elevation of the Central Mid-level escalator and walkway system Fig.19. (right) Location of the Central Mid-level escalator and walkway system

Domain | Multi-level Ecology

Fig.20. (top) Elevated walkways and underground tunnels of Central Fig.21. (middle)Elevated walkways being utilized as social meeting spaces Fig.22. (bottom) Complex circulation under and over ground in Central

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HIGH LINE, NEW YORK Case study of a public promenade in New York Overview A public park above the hubbub, a space where nature softens the city’s abrasiveness, the High Line is a 2.33-km-long elevated linear park and green-way created on a former New York Central Railroad spur on the west side of Manhattan in New York City. The project itself is rather simple and modest in design. It serves as a skeleton for a place just swelling with horticultural wonder, diverse programmes designed for the pedestrian.

The success of High Line is based on an easily understandable and sustainable model of community engagement.

The framework made up of plants, paths, staircases, social spaces and vistas is one that the community has utilized to bring together social, economic, and environmental value opportunity with respect to their existing space and culture.

It is not merely another park, but represents the ability of a community to come together and connect their objectives to a framework in a new and innovative way in order to create and distribute economic prosperity.

It exemplifies a new-found freedom from the hustle and bustle of city life allowing many New Yorkers especially to feel a part of something different that is so well-integrated within their ordinary existing environment just 30 feet above them.

Fig.23. (top) View of the socially active park High Line, New York

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Domain | Multi-level Ecology

Viewing gallery [1] The ends of High Line were conceived as viewing galleries away from the heavy pedestrian flow where people can stop and look down onto the city. Nodes that are not an integral part of a network are utilized as leisurely spaces.

Narrow Walkway [2] The width of the High Line varies between 9 metres and 15 metres with its walkway width between 2.5 metres to 6 metres at the junction with the remainder occupied by plantation. The narrow walkway fails to smoothly channel its pedestrian load.

Mile-long opera [3] The Mile-long Opera is a citywide public engagement project that brought together 1,000 singers from across New York for free performances on the High Line.

It invites audiences to move in and out of groups of singers as they walk along the High Line.

Seating [4] Benches protruding from the pavement are scattered in small pockets away from the primary walkways.

These spaces also allow people to meander away from the heavy pedestrian flow, often brimming with tourists.

Fig.24. (1 from top) Viewing gallery at the Eastern end of High Line Fig.25. (2) View of the narrow walkway at High Line Fig.26. (3) View of the Milelong orchestra, late night performances at the city that never sleeps.

Fig.27. (4) Wooden benches scattered at the High Line Fig.28. (5) People spilling out onto the lawns at High Line Fig.29. (6) Amphitheatre at High Line during lunchtime.

Fig.30. (7) Stepped seating along existing facades at High Line

Spill-out spaces [5] There are also patches of turf adjacent to the walkway where people can step away from the scurry. These patches are however sandwiched between the walkway and building facades and have poor horizontal and sky view factors.

Amphitheatre [6] The amphitheatre is arguably the most widely used space at the High Line. It is located away from the promenade, overlooking a small stage with the bustling street in the background. This space is primarily utilized for performance arts and by corporate crowds during lunch breaks.

Group Seating [7] Small pockets of seating are provided alongside existing facades that look onto the vista of the promenade. These spaces are vital as they function as spill-out areas with the most potential for social interaction.

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Limitations The High Line project over the years has transformed into predominantly a tourist attraction. It experiences pedestrian loads that it was not designed to withstand.

The narrow width of High Line limits activity and restricts its pedestrian users to slow down or halt in most of its constituent spaces. It is evident that wider segments of the linear pathway perform the best in terms of promoting social interaction.

The lack of exit points apply further emphasis on its slenderness. Swarms of people often clog these exit points with crowds spilling out onto the streets.

The project stands in isolation and does little in integrating with the adjacent buildings losing the opportunity to build spatial relationships in the urban fabric.

Conclusions The project is not conceived to provide shorter or faster routes for pedestrian commute. Instead, it provides an ecological platform that helps sustain the socio-environmental landscape of New York.

The High line combines the vegetation and walking pavements of different proportions into a shared meandering surface such that people and plants can fluidly commingle. Blurring the line between plants and hardscape breaks the monotony of New York’s hard grid layout.

The High Line project is primarily a destination and functioning primarily as a tourist attraction, it has become a tourist-clogged promenade and

46

a catalyst for some of the most rapid gentrification in the city’s history.

According to the park’s Web site, about 4 million people visited the High Line in 2015, only less than half of them New Yorkers. The High Line has become a tourist-clogged promenade and a catalyst for some of the most rapid gentrification in the city’s history. It is not just overcrowding aboard the High Line, but also on the streets around it. This crowding disrupts the envisioned, early year ecosystem of High Line.

There are small pockets of spaces where seating has been provided. These spaces are scarce and insufficient for even small groups that want to sit together.

This raises two questions pertaining to the integration of public spaces with the urban fabric: 1. How can a maximum width deeper than 4 metres, affect the spatial character, pedestrian movement and the programmatic variation on the promenade?

2. How would a similar spatial arrangement perform if its spaces were connected at multiple levels?

Domain | Multi-level Ecology

Plan of High Line cutting into existing buildings

Existing High Line section

Connected at multiple levels

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DOMAIN CONCLUSION Problems and ambition Summarizing the domain, three crucial issues are identified, which will guide the studies in the research development stage. Further, the issues will be addressed by the corresponding strategies for the development of an integrated system. The three key aspects that will be addressed are: 1.

Lack of open space Open space deficiency is one of the most pressing issues in high-density cities like Hong Kong.

As land space resources approach saturation, elevated open spaces may be a viable solution.

Assuming that introducing public spaces connected to private development is feasible, we aim to improve the current standards by introducing a system of multi-level open spaces.

2.

Connectivity of open spaces It is imperative that these open spaces are well connected. Linked open spaces are not only beneficial for social interaction, but they also contribute to improving the urban ecology of the city. Being integrated or in proximity to primary pedestrian walkways increases both users and usability.

3.

Lack of freshwater resources It is understood that the new infrastructure at this scale cannot be created in isolation. The increased amounts of open spaces would require a manifold increase in the water demand for the area. We aim to meet this water demand by introducing a currently non-existent rainwater harvesting strategy in order to drive Sai Ying Pun to not only be self-sustaining during the summers when rainfall is abundant, but also the winter when rainfall is scarce.

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4.

Lack of integration of public spaces with the urban fabric Open spaces currently are primarily considered as destinations, and are not incorporated in the users’ daily rhythms. In order to maximize on the benefit that the public spaces prove, they must be integrated with the urban fabric, within the users’ daily commute and overlap with existing institutions.

The four issues incorporate both social and environmental aspects and will be tackled at both urban and architectural scale. In the research development chapter, these issues will be explored in detail, pertaining to the selected site.

The ambition of this design research is to develop an ecological multi-level open space system for existing high-density areas.

Domain | Multi-level Ecology

49

50

Domain | Multi-level Ecology

RESEARCH QUESTION How can innovative configurations of dynamic multi-level open spaces enhance social interactions in high-rise high-density urban environments?

51

52

3 Method

53

Global

Proposed

Water Storage Tank

Open Space Elements

Distribution

Cluster design

Test experiments

Integrated System Experiment

Local Area Zoning

Open space distribution

Lawn

Network connection

Pavement

Hydrological strategy

Determined programme

Open Space Distribution

Network Connection

Local

Output

Planter

Open space with connection hierarchy Space cluster for water storage tanks

Programmatic Distribution

Hydrological system

Multi-level Open Spaces

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Planting Distribution

Local Topography

Method | Multi-level Ecology

OVERVIEW The information gathered from the domain comprises constructive input for formulating experiments to explore our research focus. To make use of its full extent, this data needs to be thoroughly studied, analysed and broken down. These involve digital tools as well as research of existing practices.

The complex systems in this project require the integration of several design and analysis tools at various scales. The methodologies incorporated to develop a systematic design strategy, have been essential to the process followed throughout our exploration. We believe it is imperative to develop the research at both global and local scale to get a comprehensive understanding of the site.

At the urban scale, to understand the composition and organisation of the existing urban tissue, two test experiments are conducted. A GA (Generative Algorithm) is used to find the optimal location and size of the open spaces. The result of this experiment is then used as the input for the network generation experiment. The network generation experiment is devised to create and optimise the network.

and size of the open spaces. As it is imperative for the open space and network generation to inform the other, an integration experiment is conducted that simultaneously creates the open spaces as well as the connection network. Additionally,the hydrological system is incorporated within this experiment by locating and determining capacity of underground water storage tanks.

At the local scale, three clusters of diverse spatial character and programme are selected which are then zoned into areas that incorporate pavements, planting and the designated programme. This is done by conducting a series of environmental analysis as well as a thorough pedestrian mapping on the open space network. The planting strategy is incorporated in these public spaces. The topography of the public surfaces are varied based on factors such as the planting strategy, shading, privacy to residential units as well as environmental factors. The activity in the spaces are then detailed, highlighting materiality and activity in the spaces. The results from the urban and local scales are then combined to form the design proposal.

The solutions of global test experiments are selected and studied individually through conducting a series of postanalysis on them. The post-analysis result will drive the selection of the fittest solution for the design proposal.

From the results of the test experiments, we learn that the chronology of experiments favours the open space generation while the network generation only supplements the spaces. This does not produce a desired result as the network generation must be an equally important driver in determining the position

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DESIGN METHOD

Open Space Generation GA Multi-criteria optimization is used to combine different evaluation parameters into a physical design. Evaluating multiple criteria in a GA provides a range of solutions that can be individually evaluated and ranked based on the criteria. As no single solution is the best solution, the advantage of using this evaluation method is that it provides designers with the opportunity to decide which solution out of a plethora of iterations they deem fit.

These algorithms are designed to find the best combination of variables (genes) to produce fit solutions (phenotypes), using genetic principles of mutation, crossover and elitism to increase the speed of the process.

Pareto front which is a set of solutions, being chosen as optimal, if no objective can be improved without sacrificing at least one other objective.

DESIGN ANALYSIS

Pedestrian mapping Pedestrian simulation is an accurate representation of the human walking behaviour and dynamics in a virtual environment. In rule-based pedestrian simulation models, the focus is set on the pedestrians’ intrinsic behaviour, implementing a decision-making based on predefined rules, often justified from psychology, according to the current situation, the neighbourhood and the agenda of the individual pedestrian. Wayfinding, population density at a given time, varying pace of the agents and crowding can be quantified and visualized and aid in designing spaces as per the movement patterns.

Example of pedestrian mapping performed on a built cluster in Sai Ying Pun

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Method | Multi-level Ecology

Sunlight Hour Analysis Sunlight hour analysis calculates the number of hours of direct sunlight received by input geometry using sun vectors from the simulated sun path of a region and during a target period.

This tool can be used to evaluate the number of hours of sunlight received by vegetation in an open space or the hours where direct sunlight might make a specific outdoor space comfortable or uncomfortable.

Example of sunlight hour analysis performed on for an analysis period of 14 hours

Shading Analysis Shading analysis helps determine the areas of the input geometry that will receive less sunlight or remain in a shadow during a particular time of the year. With input data such as location, day of the year and time of the day, an overlapping range of shadows is created which indicates the amount of time a particular area is in the shade over the day.

A shadow analysis done on the existing urban fabric of the site depicts the impact of the generated spaces on the site.

Example of shading analysis performed on for an analysis period for 14 hours

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Computational Fluid Dynamics (CFD) Computational Fluid Dynamics uses the ability of computers to quickly and efficiently tackle finite elements to analyse fluid flow-related problems in a specific environment.

Surface pressures and velocity vectors can be calculated using this tool. Autodesk Simulation CFD software is used in this project first to analyse the wind flow on the selected site, the result of which is compared to the design proposal.

CFD allows us to inform the design by quantitatively analysing wind velocities.

Wind velocity analysis on urban patch in simulation CFD

Horizontal View Factor (isovist) Shading analysis helps determine the areas of the input geometry that will receive less sunlight or remain in a shadow during a particular time of the year. With input data such as location, day of the tear and time of the day, an overlapping range of shadows is created which indicates the amount of time a particular area is in the shade over the day.

A shadow analysis done on the existing urban fabric of the site depicts the impact of the generated spaces on the site.

Isovist factor represents horizontal openness

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Method | Multi-level Ecology

Sky View Analysis (SVFs) A Sky View Factor represents the ratio at a point in space between the visible sky and a hemisphere centred over the analyzed location.

Studying the SVF is essential since it is a measurement that can be used as a proxy for radiation, which influences air temperature and other related weather phenomena.

SVF is a crucial ingredient to study urban climate and urban heat island effects, elements that are important for citizen well-being.

The SVF is a measure of how much sky is visible at a given location

NETWORK ANALYSIS

Graph theory To evaluate topological relationships between the generated spaces and the existing urban fabric, a quantitative theoretical frame is used, namely the Network Theory, the principles of which are derived from Graph Theory.

Betweenness centrality in graph theory, is a measure of centrality based on the shortest paths. In the case of this project, it shows how often an edge (path) happens to be present close to the shortest path between an origin and a destination. In a connected graph, closeness centrality of a node is a measure of centrality in a network, the more central a node is, the closer it is to all other nodes. The degree of closeness and betweenness centrality is measured within the GA and forms the basis for the network system.

Syntactical analysis of topological relationships between nodes

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4 Research Development

61

3

2

4

1

1

Hong Kong Island

2

Kowloon

3

New Territories

4

Lantau Island Sai Ying Pun People's Republic of China (PRC)

SAI YING PUN Introduction to the selected site Sai Ying Pun is located in the old district of Hong Kong, sandwiched between the Belcher Bay and the Lung Fu Shan mountain range. This area is part of the old district planned in the early 1900s. The site division of the time is noticeable in today’s buildings as well. The small sites which formerly comprised of low-rise brick houses, now have skyscrapers of similar footprints. These slender skyscrapers are also called ‘Pencil Towers’.

Even though the commute via these stairs may be unfavourable, they are vital to the urban fabric of Sai Ying Pun.

Located at the foothills of the mountain range, the site has a steep slope. The slope, coupled with the unfavourable climate makes pedestrian movement extremely strenuous.

The datum of the buildings are generally created by cutting into the sloped land to create horizontal platforms. This method creates substantial differences between adjacent levels in the direction of the sloping terrain(N-S).

These level differences are bridged by a series of stairs throughout the area, with clear pedestrianized multi-level connections. These stairs are seldom used when it rains and during peak summers.

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Fig.31. Location of Sai Ying Pun in Hong Kong

Research Development | Multi-level Ecology

General Data site

0.423 km2 population

41,748 population density

98,695 people/ km2

Fig.32. Aerial view of Sai Ying Pun, Hong Kong

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TOPOGRAPHY AND TRANSPORTATION NETWORK Accessibility study of the site The area is well served by minibuses, city buses, taxis, and the traditional Hong Kong tram. Many bus routes run along Des Voeux Road and Queens Road West which are located at the top and bottom of Sai Ying Pun respectively. Buses are limited to the two main roads due to the restrictions of the steep slope.

Residents are forced to commute up and down the slope to gain access to the buses.

The Mass Transit Railway (MTR) is considered to be the most efficient means of public transportation in Hong Kong. It is regarded as one of the world’s leading railways for safety, reliability and costefficiency. Unlike other modes of public transport, the operational reliability of MTR trains is unaffected by traffic conditions. Compared to the road mass transit means, the MTR is also more accessible to residents on-site as there are four MTR exits within Sai Ying Pun. In the adjacent diagrams, the centres of the circles mark the exits to the MTR stations, and the circles represent a range of 5 minutes walking distance from the exits. This 5 minutes radius varies from different

64

stations due to the variation in the sloped topography.

While generating the proposed multi-level network, important programmes such as the MTR exits will hold priority, such that connectivity to these places is enhanced.

Research Development | Multi-level Ecology

+310m

+150m

+4m -50m

Section through Sai Ying Pun

Map showing road and transportation network ROAD NETWORK

TRANSPORTATION

primary (district)

MTR entry/exit point

bus route

primary (local)

MTR Station

bus station

secondary

MTR rail

flyover

tram rail

cross harbour tunnel

tram station

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A

B

C

D D’ A’

B’

C’

Legend sloped road stairs stairs + landing escalator

Map showing types of pedestrian road

PEDESTRIAN CIRCULATION Walkability study of the site The pedestrian circulation in Sai Ying Pun is bound to street level. Due to the steep topography, there is widespread usage of staircases and escalators on site.

The average inclination of pathways at the lower end of the site is 1:10 (height:length) ratio, while the standard for barrier-free (accessible to the disabled) is 1:12. Higher up the site, the slope gets steeper, which brings about the need to incorporate stairways in the pathways.

In the southern regions of the site, the slope gets as steep as 1:4. To access these areas, escalators are constructed as this ratio is too steep for stairways.

Vehicular traffic does not have access to this area as the slope may cause a blockage. Furthermore, though the streets get steeper up the site, the width continues to measure just 1.5 metres.

As the access to public buses is only on the north and south ends of the site, walking along the steep slope is unavoidable. These street conditions, coupled with environmental factors, makes the commute physically taxing.

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Fig.33. (next page left) Secondary Street (First Street) Fig.34. (next page middle) Central Street (Third Street) Fig.35. (next page bottom) Central Street (Queens Street)

Research Development | Multi-level Ecology

13.04° 20.48°

1.5

7 10

1.5

1.8 1

1.5 20.48°

20.48°

3.5 8.5

13.04°

13.04°

5.17°

5.17°

Section D-D’ Central street

Section A-A' Queens street

Section B-B' Third street

Section C-C' First street

13.04°

5.17°

Legend residential commercial

1.5

7 10

1.5

1.5

7 10

1.8 1

1.5

3.5 8.5

1.5

Sloped Pedestrian Roads gradient altitude

Stairs + Landing gradient

altitude

Escalator & Stairs + Landing gradient altitude

1:10

1:5

+15.9 m

1:4

+7.1 m

+30 m

1.5

7 10

7 10

5.17°

1.5

1.5

1.5

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LEGEND Residential residential - low rise residential - tower Commercial commercial - podium offices hotel Amenity hospital/ clinic government school wholesale market car park community/ recreational/ market

Map of Sai Ying Pun showing the building types and programme

Programmes AND TYPES OF BUILDINGS The strategy of building on top of the existing structure By analysing the programmes, the built form corresponding to the programmes and their structure, we will derive strategies to integrate the elevated open spaces with the existing built structures.

Sai Ying Pun mainly comprises of two types of development - the pencil tower and the tower podium type. Most of the buildings on site belong to the pencil tower category. Since the site is part of the old development, small plot footprints are retained to the day resulting in slender towers. There are only a few cases of podium tower typology as this is part of the newer development.

Shophouses present on-site are part of the old development as well and are going to be redeveloped in the near future. Commercial buildings are mainly developed on the seaside or in proximity to main roads, whereas up the hill, it is mostly residential areas.

Most buildings on the site are either concrete framed structures or hybrids of concrete framed and shear

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wall structures. The external and the internal walls, windows etc. are non-structural elements and can be modified as per the user need. This gives us the opportunity to create open spaces on the existing buildings by removing the non-structural elements without compromising on the structural integrity of the building.

Research Development | Multi-level Ecology

FLOOR PLAN

PROGRAMME

STRUCTURE

shop house

commercial + residential

concrete frame

pencil tower

residential

concrete shear wall

cruciform tower

residential

concrete shear wall

tower + podium

commercial + residential

concrete frame + shear wall

tower

office/ commercial

concrete frame

concrete shear wall structure

concrete frame structure

Removal of non-structural elements to create new open spaces in existing buildings

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site building foot-print open space

Map showing open space and building footprint in Sai Ying Pun

OPEN SPACES IN SAI YING PUN Assessment of existing open spaces The current open space standard in Hong Kong recommended by their government is 2m²/person, which is low considering that the current WHO standard of open space area is 9m²/person.

Furthermore, the existing green open spaces do not match the international standards in terms of user experience as well. These spaces are rendered unpleasant due to Hong Kong’s high built density.

These are, for the most part, tiny pockets of dark areas that lack sufficient air circulation.

There is a rare spillage of sports facilities such as outdoor basketball or tennis courts with next to no surrounding vegetation.

Individual blocks currently do not have a standard regulation of the amount of Open Space that they must comprise of.

One of the largest parks on site is the Sun Yet Sen Memorial Park, the usage of which is low considering the available green area ratio of Sai Ying Pun. It is suspected that this is due to its location.

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Currently, the location of this park is entirely isolated sandwiched between the highway and the sea.

The usage could have been much higher if it were integrated with the rest of Sai Ying Pun.

Research Development | Multi-level Ecology

Fig.36. stairs between buildings

Fig.37. Urban open space created from residue gap remaining from the redevelopment of the adjacent building.

Existing Open Space Assessment open space

46,000 km2 open space per person

Open Space Quantity Ambition

1.1 m /person 2

new open space provision site

423,000 km2 population

41,748

+200% target open space per person

>5 m2/person

population density

98,695 people/ km2

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EXISTING OPEN SPACES IN SAI YING PUN Evaluation of existing open spaces based on sunlight hour, sky view and isovist

Pocket Parks Due to the steep slope of the site, this park is situated on an incline that makes it difficult for certain groups of people to access. The incline is higher on the southern edge of the site because of the topography. A portion of the park receives a meagre amount of sunlight since high rise towers surround it.

Elements: Stairs, Light, Greenery, Benches General Data Length 50m Width 50m Area 1360m2 Type Park Fig.38. Street view of a pocket park

Stairways The stairways in Sai Ying Pun are a component of the street walkways and are incorporated to make the undulating topography accessible. These stairways take the width of the walkway and are generally quite narrow considering the pedestrian load. Staircases are generally sandwiched between the narrow streets and the building, resulting in a low sky view and are mostly dark spaces.

Elements: Stairs General Data Length 10m Width 5m Area 100m2 Type Aisle Fig.39. Street view of a stairway

Side Walks The sidewalks in Sai Ying Pun account for 70% of the lateral pedestrian circulation. The narrow paths in some areas along the slope are exceedingly steep and make pedestrian circulation particularly tasking. These pathways have a higher sky view and receive more sunlight compared to other open spaces as they are situated next to roads.

Elements: Stairs, Light, Greenery, Benches General Data Length 50m Width 2m Area 200m2 Type Aisle Fig.40. Street view of a side walk

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Research Development | Multi-level Ecology

Alley As most buildings now have a frontage facing the streets, alleys are seldom accessed. These narrow alleys are mainly used for collecting garbage and service entrances as they have low spatial quality. In some instances in the old district, due to the lack of open spaces, people are forced to use these dark alleyways as spill out areas. The alleys in Sai Ying Pun are perceived to be dangerous due to the lack of usage and cases of unethical activities.

Elements: Steps, Small Shops

Fig.41. Street view of an alley

General Data Length 30m Width 10m Area 300m2 Type Aisle, Market

POSPD (Public Open Space in Private Developments) The provision of POSPD assists in achieving an integrated design, optimises land use and synchronises the availability of public open space and the community’s needs. Creating open spaces in private developments for public use is an efficient way to enhance the urban environment. As these spaces are part of private development, they have built structures on top, due to which they receive a low amount of sunlight.

Elements: Stairs, Light, Greenery, Benches

Fig.42. Street view of a POSPD

General Data Length 20m Width 15m Area 350m2 Type Aisle

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Open Space Quality Assessment

wandering

with attractors

passing through

Social space

open space network

meandering

Circulation space

sufficient sunlight

higher spatial openness

Conclusion A quality open space should perform well environmentally, be well connected to an efficient open space network, have a high perception of openness and urban greenery either directly or indirectly linked to space.

Most spaces in Sai Ying Pun do not perform well environmentally. Parks, alleys, staircases and privately developed areas do not receive sufficient sunlight and lack ventilation. Additionally, these spaces are not shaded, making pedestrian commute during rain and strong sunlight difficult.

Open spaces such as alleys and individual staircases are not part of the primary routes that pedestrians take. Dark, secluded spaces as such are considered unsafe for occasional usage.

Openness is a perceptual quality of a space and is associated with analyzing the space to the physical size perceived by a user. Pocket spaces in Sai Ying Pun that have a low openness and/or are occupied by many users may evoke a feeling of claustrophobia.

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None of the above categories of open spaces in Sai Ying Pun performs well in the spatial quality analysis.

In subtropical climates, open spaces must shelter its users from the harsh sun as well as the rain. At the same time, the urban conditions dictate that there must be bright spaces that receive an ample amount of sunlight despite the wall effect imposed by the high-rise.

Research Development | Multi-level Ecology

POCKET PARK

POSPD

STAIRCASE

SIDE WALK

ALLEY

>14h

0h

High

Low

High

Low

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SITE ENVIRONMENTAL PERFORMANCE Sunlight hours and wind study Summer During summers, the site receives sunlight in abundance. However, since the sun path is on North and not directly overhead, the streets and lowrise building in Sai Ying Pun receive insufficient sunlight.

From June to August, the prevailing wind flows from the south-west, which is obstructed by the hill. The lack of ventilation on-site further contributes towards the high humidity during these months.

Winter During winters, there is a shift in the sun path to the south. As the sunlight is received from the south, a large portion of it is obstructed by the hill, especially when the sun is low. Due to this, the northern faces of buildings receive a very low amount of sunlight.

The prevailing wind from September to April flows from the east. This wind carries moisture from the sea onto the site, contributing to the humidity.

This data is essential for our later research, as it informs the planting strategy incorporated in the open spaces.

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N

Research Development | Multi-level Ecology

Sunlight hour analysis Summer solstice 21st June 6:00-18:00

Sunlight hour analysis

m/s

11.0< 9.94 8.88 7.82 6.76 5.70 4.64 3.58 2.52 1.46 <0.40

8.00< 7.20 6.40 5.60 4.80 4.00 3.20 2.40 1.60 0.80 <0.00

N

m/s

Summer

N

Winter solstice 22nd December 6:00-18:00

Winter

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SUNLIGHT HOURS ANALYSIS Seasonal sunlight hour analysis The solar hour analysis has been carried out during the summer and the winter solstice. These two days have been selected as these days correspond to the extremities in sunpath shifts.

With this analysis we aim aim to understand the amount of sunlight received by the existing buildings and the seasonal change in ground level pedestrian conditions.

The analysis will be setup in two ways. Firstly, sunlight hours will be measured on the built structures during the two time periods and secondly, sunlight hours will be measured on the street.

Since the sun path during the summer solstice is on the North of Hong Kong, 70% of the north facing facades receive more than 9 hours of sunlight.

However, this implies that south facing building facades receive significantly lower incident sunlight.

80% of the south facing building facades receive less than 4 hours of sunlight.

As the sun path during the winter solstice is on the North of Hong Kong, 100% of north facing building facades receive less than 4 hours of sunlight.

55% of the north facing facades however receive more than 7 hours of sunlight.

The ground level sunlight hour analysis during the summer solstice shows that since the sun path is relatively overhead, the streets receive about 5-7 hours of sunlight. The ground level on the site receives very low sunlight when the sun is at lower angles.

It is evident from the ground level sunlight hour analysis during the winter solstice that the streets barely receive any sunlight. Only a small percentage of land, in West Sai Ying Pun receives more than 3 hours of sunlight.

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Conclusion The solar hour analysis on the buildings demonstrates that as the seasons change, different regions of the site will receive high and low amounts of sunlight. To address this phenomenon, a dynamic will be explored that will account for the summers as well as winters.

The result portrays that though the ground level does not receive sufficient sunlight, higher levels of the buildings receive ample sunlight at least on one side, all year long. This further reinforces our decision to introduce multi-level open spaces on site.

Research Development | Multi-level Ecology

Summer solstice 21st June 06:00-18:00

Winter solstice 22nd December 06:00-18:00

view from north-east

view from north-east

view from south-west

view from south-west

plan view

plan view

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URBAN VENTILATION Wind flow at different altitudes CFD Analysis has been conducted to evaluate the air ventilation of the existing site. As the intent of the project is to introduce a network of multi-level open spaces, it is important to analyse the wind flow concerning different altitudes.

Setup Two types of incident winds are experienced at Sai Ying Pun. The prevailing wind in Sai Ying Pun flows from the east with an average velocity of 3m/s. As the site is located on the foothills, it experiences a downdraft from the mountains that flows from the south. The average velocity of this wind is set up to be 1.5m/s In the urban ventilation study, wind velocity through Sai Ying Pun is analysed at the height of 2 metres, 30 metres, 50 metres, 70 metres and 90 metres. The lowest point on the site has been considered to be level 0 to measure these heights.

Analysis Analysing the wind flow at multiple levels helps study the ventilation at the pedestrian level as the topography is undulating, and a single sectional plane does not show an overall picture. The analysis is implemented on a highly dense urban patch without the great potential of air ventilation. The wind speed inside these patches goes lower than 1m/s, which is not perceived by the human body.

The 2m height analysis shows the ventilation conditions on the northern end of the site. The wind velocity is not higher than 1m/s. The existing open spaces surrounded by buildings receive a negligible amount of wind flow. At lower levels, streets oriented in the East-West direction experience higher wind velocity than streets oriented in the North-South direction.

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Since there is less density of high rise buildings in the east of Sai Ying Pun, the area experiences higher wind velocities as we can see at the 70m level.

It is noticeable that the â&#x20AC;&#x2DC;wallâ&#x20AC;&#x2122; effect on site is responsible for the poor low ventilation in most of the areas on site. However, as observed in level 70 and 90, wind funnelling through buildings may also increase wind velocity.

Conclusion Specific strategies are extracted that can be utilised in the design proposal to improve urban ventilation.

Streets oriented in the prevailing wind direction, East-West, enhance air ventilation in the urban fabric. The same principle can be applied to elevated open space for cross-ventilation.

As the wind velocity goes up with altitude, multilevel open spaces at higher altitudes will have better ventilation compared to open spaces at lower altitudes.

Open spaces that are situated at lower altitudes around East Sai Ying Pun would receive sufficient ventilation.

Research Development | Multi-level Ecology

N

m/s

Dominant wind direction in Summer

N

11.0< 9.94 8.88 7.82 6.76 5.70 4.64 3.58 2.52 1.46 <0.40

+110m

+90m

+70m

+50m

+30m

+10m

m/s

Dominant wind direction in Winter

8.00< 7.20 6.40 5.60 4.80 4.00 3.20 2.40 1.60 0.80 <0.00

m/s 7.00 6.00 5.00 4.00

EXPERIMENT SETUP Wind direction: Wind speed:

3.00

East

2.00

3 m/s

1.00 0.00

+110m +10m

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STORM WATER DISCHARGE SYSTEM Problems and ambitions Located at the foothills, the site is vulnerable to floods during heavy rain. The existing sewage system is located on the hillside above Sai Ying Pun to protect the urban area from stormwater runoff. Within the urban area, there is a network of drains that collect stormwater and discharge it into the ocean.

There exists an underground water chamber that collects stormwater during heavy rains to prevent floods. This water is subsequently expelled into the ocean as well.

Since the concrete surface does not absorb, retain or slow down the water, the drainage system receives the complete load of the surface runoff. Often due to blockage or exceedingly high stormwater loads, the site experiences flash floods. There are currently no existing water retention or harvesting techniques incorporated on-site.

In our proposal ahead, we aim to introduce a rainwater collection system. Since the site receives heavy rainfall during the summer months, rainwater can be collected by the open spaces and stored on site. This stored water will be pumped up during the winter months of scarce rainfall and will be utilized for the irrigation of open spaces.

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Research Development | Multi-level Ecology

UNDERGROUND DRAINS

UNDERGROUND STORAGE TANK

SEA (LOCAL COAST)

STORM WATER DRAINAGE TUNNEL

SEA (HONG KONG SOUTH)

SEWAGE WATER Stonecutters Island Water Treatment Work Tunnel connection chamber Preliminary Treatment Plant (PTW) STORM WATER (WESTERN DRAINAGE TUNNEL) Intake Western drainage tunnel

20.48°

13.04°

5.17°

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SITE CONCLUSION The array of complications associated with Sai Ying Pun stem from the initial ineffective planning of the old district. The tightly packed towers have saturated the land available, forcing the city to compromise on elements that are essential for a healthy society.

The lack of open space in Sai Ying Pun is a pressing concern that cannot be solved with current ground level open space distribution. The multi-level open space system that we propose will not only increase the amount of open space in Sai Ying Pun but also the spatial quality of the open space.

Our analysis points out that a majority of the existing open spaces in Sai Ying Pun are dark, isolated spaces that are not integrated with the circulation routes.

In order to address this, we aim to enhance urban ecology by connecting the open spaces and ensuring that they perform well environmentally. While providing shading for the spaces, a balance must be achieved such that there are ample sunlight and rain shade simultaneously.

Unfavourable climatic conditions, inefficient pedestrian infrastructure and the steep slope make the commute incredibly tricky. The proposed multilevel open space network will be designed to offer an easy, quick and a barrier-free walking through the site, especially along the slope.

The existing pedestrian circulation does not have a programme based hierarchy, which means that links close to essential programmes have been given the same emphasis as links that receive a minimum pedestrian flow. It is essential to prioritize circulation elements that are in proximity to spaces with an important programme or high pedestrian flow.

As we aim to increase the amount of open space onsite, it is apparent that the water requirement of the site will go up manifold. Introducing a water retention system may be a step toward sustainability.

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Research Development | Multi-level Ecology

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Research Development | Multi-level Ecology

HYDROLOGICAL SYSTEM Definition and value projections The hydrological system is the entire cycle of water movement. It is a system of interrelated components, including the processes such as precipitation, evaporation, absorption and transpiration, in addition to those structures and devices that are used to manage the system. The hydrological system is subject to different kind of weather pattern and spatial complexity and is dynamic.

Overview The aim of devising this strategy is to address the lack of freshwater issue by introducing techniques of recycling water. The scope of this system is to establish a relationship between stormwater received, grey-water and the irrigation requirements in Sai Ying Pun.

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Surface Runoff The runoff coefficient (R) is a dimensionless coefficient relating the amount of runoff to the amount of precipitation received. It is a larger value for areas with low infiltration and high runoff (pavement, steep gradient), and lower for permeable, well-vegetated areas (forest, flat land).

Runoff coefficient is a multiplication factor used to establish the proportion of the volume of rainwater that can be collected relative to the volume that falls on the surface. It accounts for losses of rainwater due to evaporation and absorption by the construction materials.

The runoff coefficient is high when measured in areas with hard surfaces as the surfaces do not absorb or retain water. While in areas with widespread vegetative surfaces, the surface runoff coefficient is low due to the tendency of plants and soil to absorb water. The soil depth and plant height/spread are inversely proportional to their corresponding runoff coefficient.

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As Sai Ying Pun is a concrete jungle, it mostly comprises of hard surfaces with very low water permeability. The runoff coefficient of urban areas as such is considerably high.

2009

2010

2011

2012

2013

2014

2015

2016

Research Development | Multi-level Ecology

Annual water consumption Annual water consumption Annual rainfall Annual rainfall Water imported from China Water imported from China Water from Hong Kong’ s catchment Water from Hong Kong’ s catchment

Runoff Coefficient (Cr) of different surface types

0.9 0.8

Asphalt surfaced area Asphalt surfaced area Pitched roof Pitched roof

0.9 0.8

Block pavement Block pavement Concrete flat roof Concrete flat roof

0.7

Run-off Coefficient Run-off Coefficient

Moss 0.7 Moss Herbs 0.6 Herbs 0.6 0.5

Lawns Lawns Shrubs Shrubs

0.5

0.4

0.4 Sedum Sedum Sedum/ gass 0.3 Sedum/Grass gass 0.2 Grass 0.2 0.1 0.1 0 00 100 200 0.3

0

100

200

Trees Trees

300 400 300 400 Substrate thickness (mm) Substrate thickness (mm)

500 500

600 600

700 700

Surface with vegetation Surface with vegetation Hard surface Hard surface

Rainwater runoff equation

Rain water yield equation

R = P + I - ET - ΔS

Yr = Ac x Rm x Cr

Water Required (l/ day) Water Required (l/ day)

R = Rainwater runoff P = Precipitation (rainfall) I = Irrigation (artificial) 10 10 ET = Evapotranspiration 9 9 ΔS = Change in storage 8 8 7 7 Rainwater runoff is the resultant sum of precipitation 6 6 and the water required for irrigation, minus 5 5 evaporation and storage change value 4 4 3 3 2 2 1 1 0 0 Tree Mixed Ground Cover Tree Mixed Ground Cover April - Oct April - Oct

where: Yr = the weekly average rainwater yield (litre/week) Ac = the collection area (m2) Rm = the average weekly rainfall (mm) Cr = the runoff coefficient

The volume of water that can be captured from the proposed open space can be estimated using the rainwater yield model.

Shrubs Shrubs

Turf Grass Turf Grass

Nov -March Nov -March

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Record low temperature

3000

Relative humidity

1000

2500

800

2000

600

1500

400

1000

500 200 0 400

25

500

452mm

0 2009

2010

2011

2012

2013

2014

2015

20

2016

300

15 Annual water consumption

200

10

Annual rainfall Water imported from China

100

5

Water from Hong Kong’ s catchment

0

0

Rainy day (daily rainfall ≥ 0.1mm) Asphalt surfaced area

Total rainfall 0.9

Pitched roof

0.8

Number of typhoonsRun-off Coefficient

0.7

Block pavement

Moss

Concrete flat roof

Herbs

0.6

Lawns

0.5 10 0.4

Shrubs

Type of Development Sedum

8

0.3

People/Hectare

Estimated Grey Water Yield (litres/person/day)

Sedum/ gass

0.26

Public Housing Grass

1740

0.1

Private Housing

1050

4

0

0

Villas and Bungalows 100

2 Village Houses 0

470

200

300

Trees

90 111 138

400

500

Schools

700

6.9

Surface with vegetation

2009 Offices

600

138

Substrate thickness (mm)

2010

Hard surface

2011

2012

2013

2014

Services

2015

2016 16.5

2017

2018

21

118-149 km/h 150-184 km/h 185 km/h or more

10 Water Required (l/ day)

9 8 7 6 5 4 3 2 1 0 Tree April - Oct

90

Mixed Nov -March

Ground Cover

Shrubs

Turf Grass

Rainy days (d)

1200

Annual Rainfall (mm)

Average rainfall (mm) Annual Water Consumption (million m³)

Record high temperature

Research Development | Multi-level Ecology

Precipitation During summer months from May to August, Hong Kong receives heavy rainfall going up to 450mm; while during the winter months from October to March, precipitation low with a maximum of 150mm.

The precipitation received during the summer months is enough to irrigate 200% of the current open spaces. However, the rainfall received during the winter months falls short of the irrigation requirement.

With an effective local rainwater harvesting system, the area may have the potential to be self-sufficient even during the winter months.

Irrigation Demand The irrigation demand of the area is calculated by the total amount of water required by the plants on site.

To estimate the amount of water that needs to be produced, this annual demand is subtracted by the rainwater utilized by the plants.

As summer months receive a high amount of rainfall, the resultant irrigation demand is low, and since winter months receive low rainfall, the irrigation demands are high.

Precipitation + Irrigation demand Evapotranspiration = Surplus water Overall system

Greywater Greywater is relatively clean wastewater from baths, sinks, washing machines, and other kitchen appliances. This water has the potential to be locally treated and reused for irrigation of plants.

The local yield of grey water in Sai Ying Pun is higher than the total irrigation demand as the area is mostly residential, and the greywater yield remains virtually constant year long.

Annually, more than 300,000mÂł of greywater can be utilized for irrigation with an efficient treatment system.

The objective of this strategy is to enable the site to meet its water irrigation needs locally.

The summer months receive high rainfall that exceeds the irrigation requirements by 127,000mÂł.

This excess water will be treated and stored in underground storage tanks for future use.

During the winter months, the rainfall falls short of the irrigation demand by 150,000mÂł. In this case, water previously treated and stored is pumped up to the open areas for irrigation purposes.

The underground water storage containers will be clustered according to the buildings and the morphology of the urban grids. As high-rise towers have deep foundations, the storage will be located under roads or existing open spaces at a safe offset from built structures.

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Research Development | Multi-level Ecology

RAINWATER HARVESTING SYSTEM Overview As established before, Hong Kong has a deficiency of freshwater resources. Having increased the green open space area by 240%, the demand for water has risen manifold as well. This has been addressed by proposing a local water harvesting strategy that will drive the site towards selfsatisfying its water needs.

This system will need to be dynamic, functioning differently during different seasons based on precipitation received.

The driving principle of this system is to collect and store the excess surplus rainwater received by the site during the summer months and use this excess water during winter months when the precipitation is low.

As established with the result of the open space generation experiment, 66% of the total open space area is subject to vegetation (41000m2) based on this area. Irrigation requirement and water catchment values have been derived.

93

green spaces

precipitation

94

reduce surface runoff

city surface storage tank

excess water

existing sewage system

sea

January

December

November

October

September

Precipitation vs Irrigation Demand

2015

2016

2017

2018

0

1 3

Total Rainfall (m)

2

4

5

Quarterly Requirement Difference

Recycled Grey Water

Existing sewage system

August

July

June

May

April

March

To Stormwater Storage System

Granular Base

Sloped Perforated Asphalt Pavement

+167,925 m3

284,925 m3

140,000 m3

+

April - June 312,550 m3

-73,925 m3

284,925 m3

140,000 m3

+

Oct - Dec 71,000 m3

+151,180 m3

of water

-69,825 m3

284,925 m3

140,000 m3

+

Jan - Mar 75,100 m3

Rainfall Collected in Winter 146,100 m3

Water Required/5m2/year 1,139,700 m3

Green Area 60% of Total Open Space 146,118 m2

Population 41,748 People

This system Annually stores

Stored for winter usage

+127,005 m3

284,925 m3

140,000 m3

+

July - Sept 271,930 m3

Rainfall Collected in Summer 584,480 m3

More than the required amount

Water Required/5m2/year 0.75m3 x 52 weeks

Green Area Standard 5m2/person

Per Person

Water Requirement Calculation

Recycled water to building

February

building use Curb Pavers to be removed as Tree Grows

precipitation > irrigation demand

Sloping concrete base to guide the water to the drainage pipes

Red Clay

Sandy Loam Soil

Setting Bed with Filter Fabric

Bark Mulch Permeable Concrete or Pavers

Typical Section detail of a Generated Open Space

This amount of water stored lasts for 1 month before the tanks empty out completely

Total Volume of Storage Required 127,070 m3

2 weeks of Recycled Grey-water 21,538 m3

2 weeks of maximum rainfall 43,830 m3

Excess water for winter 127,005 m3

Factors affecting Volume of Storage Tank

Precipitation

Rainwater runoff from green spaces

Excess rainwater

Rainwater runoff from city surface

Existing sewage system

Research Development | Multi-level Ecology

Summer During the summer months from May to September, Hong Kong receives heavy rainfall going up to 450mm.

During these months, green open spaces can potentially reclaim approximately 58,500mÂł of water through the generated spaces and surface runoff.

The irrigation requirement for the vegetation on the open spaces during these months is 38,000 mÂł which is 65% of the total rainwater collected.

This implies that there is an excess of 20,500 mÂł (35% of the rainwater collected) of rainwater that can be collected, treated and stored for future use.

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precipitation

96 green spaces storage tank

city surface

existing sewage system

sea

January

December

November

October

September

2015

2016

2017

1 3

Total Rainfall (m)

2

building

2018

0

4

5

Quarterly Requirement Difference

Recycled Grey Water

Existing sewage system

August

July

June

May

April

March

Granular Base

Sloped Perforated Asphalt Pavement

+167,925 m3

284,925 m3

140,000 m3

+

April - June 312,550 m3

-73,925 m3

284,925 m3

140,000 m3

+

Oct - Dec 71,000 m3

+151,180 m3

of water

-69,825 m3

284,925 m3

140,000 m3

+

Jan - Mar 75,100 m3

Rainfall Collected in Winter 146,100 m3

Water Required/5m2/year 1,139,700 m3

Green Area 60% of Total Open Space 146,118 m2

Population 41,748 People

This system Annually stores

Stored for winter usage

+127,005 m3

284,925 m3

140,000 m3

+

July - Sept 271,930 m3

Rainfall Collected in Summer 584,480 m3

More than the required amount

Water Required/5m2/year 0.75m3 x 52 weeks

Green Area Standard 5m2/person

Per Person

Water Requirement Calculation

Grey water to green space

February

To Stormwater Storage System

Curb Pavers to be removed as Tree Grows

precipitation > irrigation demand

Sloping concrete base to guide the water to the drainage pipes

Red Clay

Sandy Loam Soil

Setting Bed with Filter Fabric

Bark Mulch Permeable Concrete or Pavers

Typical Section detail of a Generated Open Space

This amount of water stored lasts for 1 month before the tanks empty out completely

Total Volume of Storage Required 127,070 m3

2 weeks of Recycled Grey-water 21,538 m3

2 weeks of maximum rainfall 43,830 m3

Excess water for winter 127,005 m3

Factors affecting Volume of Storage Tank

Precipitation

Rainwater runoff from green spaces

Excess rainwater

Rainwater runoff from city surface

Existing sewage system

Precipitation vs Irrigation Demand

Research Development | Multi-level Ecology

Winter During the winter months from October to March, Hong Kong receives scarce rainfall going up to 150mm; During these months, green open spaces can collect 155,000m3 of water through the generated spaces and surface runoff.

The irrigation requirement for the vegetation on the open spaces during these months is 380,000 m続. This implies that the collected precipitation during the winter falls short by 225,000 m続.

During these months, the 205,000 m続 of water treated and stored will be pumped up to the spaces and will be available for use, resulting in only a 20,000m続 shortage.

With this system, more than 94% of the irrigation demand is met by locally storing rainwater.

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Research Development | Multi-level Ecology

PLANTING STRATEGY Overview The objective of this research is to develop a set of holistic planting strategies that maximize the benefits of urban plantation and minimize the negative impacts that arise from developing hard infrastructure to bear such plantations.

By collecting, analysing and comparing the parameters that support growth of the plants, a catalogue of plants is developed for the open space system. This will allow the establishment of a set of criteria for selecting the suitable plants for the proposed spaces to achieve various design objectives.

99

DESIGN OBJECTIVES AND CHALLENGES Importance of urban greenery Design Objectives The main goals of the proposed multi-level open space system are to provide quality spaces for social interactions and to mitigate the flooding problem on-site by reducing stormwater runoff.

Appropriate planting design can help enhance the spatial quality of proposed spaces, reduce stormwater runoff as well as enhance ecological biodiversity.

1. Enhanced spatial quality Plants can help to improve the spatial quality by providing adequate shading at the required area. Plants also offer substantial social benefits to open spaces, improving air quality, absorbing noise and enhancing aesthetics.

2.

Reducing stormwater runoff A vegetated surface can reduce stormwater runoff by retaining the water in the plants and the soil. By intercepting and retarding precipitation hitting the ground, vegetation substantially diminishes both the volume and rate of stormwater runoff. This helps in protecting the soil from erosion and reducing flash floods.

3.

Enhance ecological biodiversity The coexistence of different urban plants can enhance the overall health of the urban environment. By creating layers of connected spaces with vegetation, plants can establish an ecological corridor between animals of different tiers in the food chain. A recent study shows that a variation of tree height can enrich the urban bird species(Huang, Qiongyu, Swatantran, Dubayah, and Goetz, 2014).

100

Design Challenge There are substantial challenges faced pertaining to planting on high-rise buildings. As different plants have different requirements to thrive, there is a need to select appropriate species for different environmental conditions such as incident sunlight, wind resistance and altitude limitations.

Additionally, different plants also bear different properties that specifically relate to the requirements of distinct programmes. For example, plants around residential areas must have a widespread canopy to increase privacy and noise insulation.

The structural limitations of the provided infrastructure are also a practical challenge.

Generally, open spaces at high altitudes comprise of lightweight plants that require a shallow soil depth.

Research Development | Multi-level Ecology

Enhance spatial quality precipitation

retention

Storm water management

to storage tank

infiltration

infiltration

tion

pira

ans potr

Eva

interception

run-off

black kite

sparrow fruit bat

Ab

spider

Tre e

ove Tre e La

La

yer

yer

beetle/ Earth worm butterfly

Sh

rub

Enhancing ecological biodiversity

Gr ou

La

yer

nd

cov er

La

yer

101

SPECIES AND THEIR PARAMETERS Data collection and cataloguing The principal environmental requirements to sustain plant growth include sufficient space for root and canopy development, adequate sunlight, water, mineral elements, and suitable temperatures for essential physiologic processes.

The planting strategy will give a higher priority while situating plants to essential parameters that are critical to the plantâ&#x20AC;&#x2122;s growth. Satisfying the essential parameters, such as shade cast and enhancing biodiversity, will be addressed.

In-depth research has been carried out to study local species that thrive in the climate of Hong Kong. These species are categorized based on their essential parameters. These parameters can be correlated to specific requirements of planting sites to develop a planting strategy.

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B B RURU SHSH

TREE TREE

Research Development | Multi-level Ecology

Hong Kong Orchid Tree Hong Kong Orchid Tree Sunshine Tree

Glory Bush

Dwarf UmbrellaGlory TreeBush DwarfNaupaka Umbrella Tree Beach Mother -in-Lawâ&#x20AC;&#x2122;s Tongue Beach Naupaka Mother -in-Lawâ&#x20AC;&#x2122;s Tongue Snake Plant Snake Plant Sanchezia

Sanchezia Coral-plant Coral-plant Red Azalea Red Azalea Lovely Azalea Lovely Azalea White Azalea White Azalea Rhapis humilis Rhapis humilis Lady Palm Lady Palm Cape Leadwort Cape Leadwort Myrte-leaved Leaf-flowe Myrte-leaved Leaf-flowe

1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0 0

Sunshine BullTree Bay Michelia chapensis Dandy Bull Bay Michelia chapensis Rose Apple Dandy Rose Honey Apple Myrtle

Honey Myrtle Weeping Fig Weeping Fig Variegated Weeping Fig Variegated Weeping Fig Batavia Cinnamon Batavia Cinnamon Hainan Elaeocarpus Hainan Elaeocarpus Common Garcinia Common Garcinia Cuban Bast Cuban Bast Queen Crape Myrtle Queen Crape Myrtle Kwai-fah Kwai-fah Frangipani Frangipani

Swiss Cheese Plant Swiss Cheese Plant

Chittagong Chickrassy Chittagong Chickrassy Scaly Tree-fern Scaly Tree-fern Sago Palm Sago Palm Chinese Fan-palm Chinese Fan-palm Dwarf Date Palm Dwarf Date Palm Dragon Juniper Dragon Juniper Buddhist Pine AglaiaBuddhist odorata Pine var. microphyllina

Ceriman Ceriman Red Strap Flower Red Strap Flower Lantana Lantana Dwarf Ixor Dwarf Ixor Chinese Ixora Chinese Ixora Chinese Hibiscus Chinese Hibiscus Golden Leaves Golden Leaves Perfume Flower Tree

EE EE TR TR B B RU RU SH SH

Allamanda Variegated Aglaia odorata var. microphyllina Perfume FlowerSky TreeFlower Allamanda Variegated Sky Flower Brazil Raintree Golden Dewdrop Brazil Raintree Golden Dewdrop Japanese Camellia Garden Croton Camellia Garden Croton Bleeding Heart Vine FukienJapanese Tea Bleeding Heart Vine Fukien Tea

Strong wind Strong wind

Irrigation demand Irrigation demand

Drought Drought

Shadow Shadow

Soil Depth Soil Depth

intensive/extensive intensive/extensive

Radar chart showing species and species parameters Species Parameters Functional Parameters

Essential Parameters Climatic Parameters 2.5

2.5

4.0

2.5

4.0

2.5

4.0

4.0

2.5

4.0

4.0

2.5

Drought Drought Drought tolerant tolerant Drought tolerant Height & soil volume Height Height & soil & Height soil volume Sunlight volume & soilhour volume requirement Sunlight Sunlight hourhour Sunlight Height requirement requirement &hour soil requirement volume Wind tolerance Height &Wind soil Sunlight Wind volume tolerance tolerance hour Windrequirement tolerance ShadeSunlight cast hourShade requirement Shade cast Wind cast Shade tolerance cast tolerantWind tolerance ShadeBiodiversity cast -high(6m)

-high(6m) -high(6m)-high(6m) -more than 6 hours-more -more thanthan 6-more -high(6m) hours 6 hours than -more 6 hours than 10m/s -high(6m) -more -more than -more than 10m/s -more than 10m/s than 6 hours -high 10m/s

-midium(4m)

HEIGHT -low(2m)

-more than -high 6 -high hours -more -high than 10m/s -high

-more than -high 10m/s -high-high-high

-midium(4m) -midium(4m) -midium(4m) -less than 6 hours -less-less thanthan 6 hours -less -midium(4m) 6 hours than-less 6 hours than 10m/s-midium(4m) -less-less than -less than 10m/s -less than 10m/s than 6 hours 10m/s -middle -less than-middle 6 hours -middle -less than -middle 10m/s-moderate -less than-moderate 10m/s -moderate -middle -moderate

& -low(2m) SOIL VOLUME -low(2m) -low(2m)

High [6m] Medium [4m] Low [2m]

SUNLIGHT HOUR -low(2m) REQUIREMENT

-500kg/m2 -500kg/m2 -500kg/m2

-low TOLERANCE

> 10m/s < 10m/s

> 6hrs < 6hrs

Height & structuralHeight limitation Height & structural & Height structural limitation & structural limitationlimitation -500kg/m2

-low(2m)WIND

Height Sunlight & hour structural analysis Sunlight limitation Sunlight Height hourhour Sunlight &analysis structural analysis hourlimitation analysis -500kg/m2

-500kg/m2

-low-low

-low -low -low-low -low-low DROUGHT TOLERANCE

high low

Wind velocity Sunlight hour Wind analysis Wind velocity velocity Wind Sunlight velocity hour analysis

tolerant Biodiversity Shade Biodiversity cast Drought Biodiversity

Drought tolerant Biodiversity

-high

-high

-high

-middle

-moderate

-moderate

-low

-low

-low CAST SHADE

BIODIVERSITY

high low

Wind velocity

Biodiversity

high low

Wind velocity

103

SOIL PARAMETERS & WATER RETENTION PERFORMANCE There is a direct relation between the size of the plant, soil volume and its water retention capability.

The diagram shows the relationship between the plant height, its mature canopy diameter, soil depth, volume and weight and the corresponding water retention capacity.

As the plant height, the mature canopy diameter, soil depth and volume increase, the water retention capacity exponentially increases as well.

In the case of this project, there is a requirement to maximize water retention, to reduce runoff, resulting in reduced chances of flash floods. It is evident from the graph that larger trees account for higher water retention.

Taking into consideration the structural and spatial limitations of the planting site, a balance of functional limitations and water retention requirement needs to be achieved.

104

Research Development | Multi-level Ecology

TREE Height: Mature canopy dia: SOIL Depth: Volume: Weight:

3m 2.0m

TREE Height: Mature canopy dia:

1.0m 1.89 m3 567kg

SOIL Depth: Volume: Weight:

3m 2.0m

TREE Height: Mature canopy dia:

1.0m 1.89 m3 567kg

SOIL Depth: Volume: Weight:

3m 2.0m

TREE Height: Mature canopy dia:

3m 2.0m

TREE Height: Mature canopy dia:

3m 2.0m

1.0m 1.89 m3 567kg

SOIL Depth: Volume: Weight:

1.0m 1.89 m3 567kg

SOIL Depth: Volume: Weight:

1.0m 1.89 m3 567kg

Soil Parameters & Water Retention Performance

GROUND COVERING

SHRUB

TREE/ SHRUB

TREE

TREE

TREE

height: >0.5m Mature canopy dia: NA

height: 1m Mature canopy dia: 0.6m

height: 2m Mature canopy dia: 1.3m

height: 3m Mature canopy dia: 2.0m

height: 4m Mature canopy dia: 2.5m

height: 5m Mature canopy dia: 3.1m

SOIL depth: 0.2m volume: 0.09m3 weight: 40kg

SOIL depth: 0.5m volume: 0.17m3 weight: 60kg

SOIL depth: 1.0m volume: 0.80m3 weight: 250kg

SOIL depth: 1.0m volume: 1.88m3 weight: 567kg

SOIL depth: 1.5m volume: 2.92m3 weight: 980kg

SOIL depth: 1.5m volume: 4.52m3 weight: 1,520kg

water retention [%] 100

4

80

3

60

2

40

1

20

0

0

1

2

3

4

5

percentage (%)

5

plant height [m] soil volume [m3]

mature cannopy dia. [m] soil depth [m] soil weight [tn]

0

plant height (m)

Vegeta�on Height and Soil Weight Comaprison 6 5 4 3 2 1 0

1

2 Tree H eight

3 Ma ture Ca nnopy Dia.

4 Soil Weight

5 Soil Depth

6 Soil V olume

105

STRUCTURAL CONSIDERATIONS Load bearing capacity of the structure The majority of open spaces are cantilevered extensions on existing structures, structural restrictions limit the span and the load carrying capacity of these extensions. The plantation load, soil load, water load, live load and dead load are subject to these structural restrictions.

The cantilever is considered to be structurally sound if the maximum deflection falls within contemporary standards. An acceptable deflection (δ) in a cantilever is a 250th fraction of its span (L). The load bearing capacity of cantilever slabs is a factor of its beam cross section.

Since the load bearing capacity of structures decreases with increase in altitude, the span of the cantilever decreases as well. The span is determined by considering a constant beam cross section, the maximum permissible uniformly distributed load is calculated. This maximum permissible load, will provide the limiting factor for the planting experiment.

106

Keeping the beam cross section constant and reducing the cantilever span with increasing altitude increase the load per unit area. In contemporary high-rise buildings, the beam cross section increases with increasing span to be able to withstand higher load, keep a low centre of mass and maintain the integrity of the structure. Similarly, we associate a specific beam depth with cantilever span. More the cantilever span, more the beam depth.

Research Development | Multi-level Ecology

Total uniform load (N/m2) is a summation of:

Structural dead load

Soil load

Water load

Live load (people)

Plant load (at peak growth)

107

CANTILEVER AND HYBRID TYPE The aim of this structural calculation is to determine the load permissible (q) on cantilever overhang to achieve minimum deflection. The resulting load limitations are implemented in the planting experiment so that the plantation does not exceed the load bearing capacity of the structure

δ = (qL4) / 8EI δ= deflection (acceptable deflection is L/250) q= load per unit length of beam L= length of beam E= Young’s modulus of the material of the beam (2e+11GPa=200000000000N/m2) I= Second moment of area of the beam

‘I’ is the capacity of a cross-section to resist bending. It depends on the shape and dimensions of the beam cross section.

For a square section beam of side length ‘x’, the second moment of area is Iy= x4/12.

For an I-section beam b d hH

a

Ix = (a h³ / 12) + (b / 12) (H³- h³) Iy = (a³ h / 12) + (b³ / 12) (H - h)

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Research Development | Multi-level Ecology

Variation in cantilever span according to altitude

0.5m light plantation

3m pathway

1.5m heavy plantation

3m pathway

5m total length

2m pathway

1.0m heavy plantation

3m total length

4m total length

Altitude: 0-75m

1.0m heavy plantation

Altitude: >210m

Altitude: 75-210m

Beam depth assumed based on cantilever span

250

250

20

250

20

360

20

20

400

310

Beam depth: 0.4m Altitude: 0-75m Cantilever span: 5m

20

350

260

Beam depth: 0.35m Altitude: 75-210m Cantilever span: 4m

15

300

Beam depth: 0.3m Altitude: >210m Cantilever span: 3m

Total Load

Permissible Loads:

5m Cantilever Beam depth: 0.4

4m Cantilever Beam depth: 0.35

3m Cantilever Beam depth: 0.3

(N/m2)

(N/m2)

(N/m2)

Dead load

1800

1600

1400

Soil load

1300

2100

2600

Plant load

900

1900

2800

Water load

1200

1800

1800

Live load

900

900

900

Summation

6100

8300

9500

109

denser canopy trees to provide shade for north facing space

less dense canopy trees as winter sun is desirable Pla

Su

nt

rfa

Tre e

denser canopy and shorter trees

&

fix

ce M

/s

less dense canopy and taller trees

tur es

a te

hru

bs

ria

ls

sta

bil

isa

Su sto bstra r m te wa for te r p l a co nt + ntr ol

Str

large trees as visual anchors

alternate species to create urban rhythm

Planting layout and placement strategies

110

uc

Cla

tur e

dd

ing

Typical planting structure and their functional layers

tio

n

Research Development | Multi-level Ecology

North

South Embedded planter and raised planter facing south and north respectively

PLANTING STRATEGIES Overview The planting layout strategy combines the previously selected vegetation and infrastructure design. This infrastructure not only supports the vegetation but also contributes to spatial quality.

The planting strategy incorporated is dynamic in nature to respond to the environmental changes and due to the varied requirements of different types of spaces.

Design Strategies As illustrated in the adjacent diagrams, different spaces are designed with varying parameters that are based on essential growth parameters, direction of sunlight, shading and altitude.

Since the sun path during the summer is on the North of Hong Kong, the North facing facades receive excessive sunlight. This issue is addressed by planting trees with dense canopies on the north facing open spaces.

The sun path during the winter months is on the South of Hong Kong, however since the sunlight hours are reduced, this sunlight is desirable. Therefore trees with less dense canopies are planted on the South facing open spaces.

Additionally, due to structural limitations, taller trees with dense canopies that weigh more are planted at lower altitudes while lighter trees that can withstand high wind velocities are planted at higher altitudes.

111

NORTH summer sun

Tree layer

4m

3.7m

3.7m

Shrub layer Herbaceous/ groundcover layer

4m

4m

A

B

3.7m

C

NORTH FACING SPACE

The above diagram is a design of a sample cantilever type open space that faces the summer sun. The open space receives high sunlight hours during summer months, and therefore, the open space needs to be shaded.

To provide shading, planters are designed to stand above ground. This enables the tree canopy to provide greater shading as well as provides public seating for space.

Additionally, taller trees with more extensive canopies are planted on the periphery of the open space in order to block direct incident sunlight while shorter trees are planted away from the periphery to increase shading.

112

B

Research Development | Multi-level Ecology

SOUTH

winter sun

Tree layer

3.5m

3.5m 3.2m

3m

Shrub layer Herbaceous/ groundcover layer 3.5m

3.2m

3.5m

SOUTH FACING SPACE

In the above scenario, a sample cantilever type open space that faces the winter sun has been designed. Hong Kong receives low sunlight during winter months and thus, it is desirable to allow sunlight onto the open space.

The subsurface planters are used in these areas to allow the entire space to be accessible. Elevated planters are not used as there is no need to increase tree height.

Short trees and shrubs are planted to allow the sunlight to penetrate the open space.

113

HIGH FLOOR

Tree layer

3.3m

3.4m

2.3m

2.5m

2.5m

Shrub layer Herbaceous/ groundcover layer

3.3m

3.2m

TREE A

2.5m

TREE B

2.5m

TREE C

3.4m

TREE B

TREE A

LOW FLOOR Tree layer

5.8m

4.2m 2.5m

Shrub layer Herbaceous/ groundcover layer

5.8m

TREE D

114

4.2m

TREE E

TREE F

Research Development | Multi-level Ecology

TREE A

TREE B

TREE C

Wodyetia bifurcata

Elaeocarpus hainanensis

Adenanthera microsperma

height: 3.5m Mature canopy dia: 1.6m

height: 2.5m Mature canopy dia: 2.0m

height: 2.5m Mature canopy dia: 2.3m

SOIL depth: 1.4m volume: 2.92m³ weight: 980kg

SOIL depth: 1.0m volume: 1.88m³ weight: 567kg

SOIL depth: 1.0m volume: 1.88m³ weight: 567kg

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Low

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Mid

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Mid

TREE D

TREE E

TREE F

Elaeocarpus hainanensis

Elaeocarpus hainanensis

Adenanthera microsperma

height: 6m Mature canopy dia: 4m

height: 2.5m Mature canopy dia: 2.0m

height: 2.5m Mature canopy dia: 2.3m

SOIL depth: 1.4m volume: 4.52m³ weight: 1,250kg

SOIL depth: 1.0m volume: 1.88m³ weight: 567kg

SOIL depth: 1.0m volume: 1.88m³ weight: 567kg

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Mid

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Mid

Shade cast: Low S.H.R.: >6hrs Wind tolerance: >10m/s Ecological: Mid

High Floor The above diagram is a design of a sample cantilever type open space that faces the summer sun. The open space receives high sunlight hours during summer months, and therefore, the open space needs to be shaded.

To provide shading, planters are designed to stand above ground. This enables the tree canopy to provide greater shading as well as provides public seating for space.

Additionally, taller trees with more extensive canopies are planted on the periphery of the open space in order to block direct incident sunlight while shorter trees are planted away from the periphery to increase shading.

Low Floor Diagram at the top is a design of a sample open space that is situated on the third floor of a highrise tower.

Heavy trees with a wide canopy are planted at this level to reduce noise pollution, improve air quality and enhance privacy.

115

116

5 Design Development

117

Global

Proposed

Water Storage Tank

Open Space Elements

Distribution

Cluster design

Test experiments

Integrated System Experiment

Local Area Zoning

Open space distribution

Lawn

Network connection

Pavement

Hydrological strategy

Determined programme

Open Space Distribution

Network Connection

Local

Output

Planter

Open space with connection hierarchy Space cluster for water storage tanks

Programmatic Distribution

Hydrological system

Multi-level Open Spaces

118

Planting Distribution

Local Topography

Design Development | Multi-level Ecology

DESIGN STRATEGIES Development of working design models GLOBAL EXPERIMENT

OPEN SPACE ELEMENTS Based on the structural learning from the buildings on site, types of open spaces will be designed, which will define the relationship of the open spaces with the corresponding building.

LOCAL SYSTEM

CLUSTER SELECTION The local scale design is carried out on clusters with varying spatial character. Multiple clusters are chosen as a single block may not comprise of the range of programmatic and functional variation that different spaces comprise of.

OPEN SPACE GENERATION I The types of open spaces previously designed will be distributed on site. Using generative algorithms, the size and location of these open spaces will be optimized.

NETWORK GENERATION A selected result from open space generation I experiment is used as a primitive to conduct this experiment. A network is created to connect the generated open spaces to enhance urban connectivity and ecology.

INTEGRATION EXPERIMENT Design insight is gained from analysis of network generation experiment result. To achieve a comprehensive, interrelated design system, adjustments are applied to the open space generation experiment by modifying the script.

SPATIAL ZONING The surface of open spaces in the clusters are zoned, determining the planting area, pathways and the public spaces.

PLANTING DISTRIBUTION With the result of the local zoning, the plantation area is extracted on which a planting experiment is carried out.

THREE DIMENSIONAL SURFACE MORPHOLOGIES The local system design is concluded by creating surface level changes to the open spaces that design drive the intended activity of the public space.

PROGRAMMATIC DISTRIBUTION To accurately sample spaces for local design, areas are organized based on spatial programme. This is done by classifying spaces correlating to criteria such as area, network hierarchy, betweenness centrality and access point proximity according to the â&#x20AC;&#x2DC;Publicness â&#x20AC;&#x2122; of the spaces.

119

120

Cantilever

Garden bridge

Hybird

Green roof

Design Development | Multi-level Ecology

OPEN SPACE SYSTEM ELEMENTS Configurations of the proposed open spaces The structure of buildings in Sai Ying Pun has been studied to understand the potential of possible connections to the buildings in the research development section.

Four types of open space configurations are proposed based on a relationship with the structure of the existing buildings: 1.

Cantilevers are spaces created by offsetting the building boundary, depending upon the solar performance of the resulting areas. Cantilevers are created on towers that do not have any other towers in proximity. The cantilever from the building is about 4-5 metres wide, considering the structural limitations.

2.

Bridges are linear spaces created by connecting two buildings within a range of 20 metres. These bridges are not footbridges in the conventional sense. Rather they merely serve as a connection between the two buildings, and they are generous spaces between two buildings which provide opportunities for social interactions.

3.

Hybrids are an amalgamation of the cantilever and bridge types. They are created when the two buildings are within a 10-meter range. As the resulting spaces are usually more significant in terms of foot-prints, these spaces would cast a larger shadow on the existing building compared to the bridge type. However, the hybrid type provides a less linear space and thus offer a more diverse opportunity for a different programme.

4.

Green roofs are spaces created on top of the lowrise shop houses. This type of space is limited to this building as it would create the least disruption to the existing structure as compared to the previous types as mentioned above. These spaces, unlike the rest, are closer to the ground level and tend to have a high degree of openness.

121

122

Design Development | Multi-level Ecology

TEST EXPERIMENT Overview Two preliminary experiments are run to develop the global design system. Experiment I determines the location, size and type of open spaces. This is done by considering factors such as ventilation, shadow cast by the generated spaces and solar exposure on the spaces. The result obtained from this experiment is used as the input for Experiment II in which a network is generated that connects the open spaces. Although this is a linear process, the evaluation of the result obtained may provide valuable insight into how the spaces perform environmentally, how they function based on connectivity and their impact on the existing urban fabric.

Through the experiments, a result is achieved that is compared to the result of a third experiment in which the open space and the network generation are integrated into one experiment.

The comparison of the two experiments will demonstrate which process creates better, more coherent results.

123

TEST EXPERIMENT 1 - OPEN SPACES GENERATION Location and size optimization Ambition This experiment aims to generate and distribute open spaces throughout the site based on criteria evaluating the spaces as well as their impact on the existing built fabric.

Setup A multi-objective evolutionary algorithm is used to determine the type, the size as well as the location of the open spaces. The bridges, cantilevers and hybrids types of open spaces will be distributed based on the morphology of existing structures. Open spaces are assigned to spaces based on their relationship with the corresponding existing buildingâ&#x20AC;&#x2122;s cross-sectional area.

Target The desired outcome of this experiment is to achieve a 200% increase in the existing open space area.

At least 60% of the open spaces generated receive more than 5 hours of sunlight a day so that plants can flourish.

The open spaces created must impose a minimal impact on the existing urban fabric in terms of shadow cast and population displaced.

The generation size of the algorithm set up is 20 with an individual count of 10; in total, 200 solutions were generated.

The body plan consists of the existing buildings on the site. The central axis of each building in the Z-direction has been identified, and points have been placed at every 20 metres on this axis. These points act as potential candidates, adjacent to which the open spaces are created. The decision to have a difference of at least 20 metres between two open spaces was taken to prevent overlapping of spaces in proximity and to reduce their impact on the existing buildings.

The different types of spaces created are roof gardens, bridges, cantilevers, hybrid of bridges and cantilevers and openings cut out in the existing structures for access.

124

Experiment Target

+200% open space area

60%

open space area that receives sunlight for planting

>10%

shadow impact to context

Design Development | Multi-level Ecology

Primitive and Body plan

Fitness Criteria

FC 1: VENTILATION maximize ventilation

FC 2: STREET & BUILDING SHADOW minimize shadow cast on surrounding buildings and street

FC 3: SOLAR EXPOSURE maximize solar exposure in summer

FC 4: SOLAR EXPOSURE maximize solar exposure in winter

Type of Space

TYPE 1: ROOF

TYPE 2: BRIDGE

TYPE 3: CANTILEVER

TYPE 4: HYBRID

TYPE 5: OPENING

125

EXPERIMENT RESULT Selected individuals for further analysis The following are the selected highest-ranking candidates corresponding to each of the fitness objectives. Candidate 5 ranks highest in the average of the objectives.

The candidate corresponding to the average of fitness objectives is not the best, nor the worstperforming in any of the fitness objectives, but a mediocre, substandard result.

Analysing the open spaces in the selected individuals, we can see that the individual corresponding to the maximise void objective produces the least amount of open space while the first candidate performs the best as it produces the most significant amount of open space.

We can see from the results that the objective that maximises the volume of the void conflicts the other three objectives. This fitness objective is responsible for bringing down the performance of the other three objectives in the average result. For this reason, it is important to prioritise the fitness criteria. Giving lesser weight to FC1 will result in solutions that perform better in the other three objectives.

The selected individuals will be further analysed and processed through multiple environmental evaluations, to gain insight into their performances and gather sufficient information for the selection of one individual for the final architectural process.

These are then evaluated through a series of postanalysis to derive the highest performing individual based on environmental criteria.

As the four fitness objectives do not carry the same weight, our design decision at this stage will be to prioritise the objectives in order to select the desired result.

126

The selected individuals are evaluated based on the type and number of open spaces they generate.

Design Development | Multi-level Ecology

Fittest individual - AREA 10 Individuals 20 generations (total 200 individuals)

1

Gen.0-Ind.6 | FC1 fittest

Gen.19-Ind.3 | FC4 fittest

Maximize void volume 187 | 107220 m2 35 | 36000 m2 15 | 8230 m2 87 | 50820 m2 50 | 12230 m2

Minimize shading on open space in summer 127 | 62120 m2 19 |17460 m2 11 | 9530 m2 47 | 25290 m2 50 | 9840 m2

Gen.16-Ind.5 | FC2 fittest

Gen.4-Ind.2 | Relative diff. rank 0

Minimize shadow on existing buildings 136 | 63300 m2 19 | 16370 m2 5 | 1830 m2 62 | 35250 m2 50 | 9840 m2

171 | 86070 m2 27 | 22700 m2 12 | 5630 m2 82 | 47900 m2 50 | 9840 m2

Gen. - Ind. | FC

Fitness criteria Number of open spaces | Total open space area

Fitness ranking chart FO1 FO4

Gen.18-Ind.5 | FC3 fittest

Minimize shading on open space in winter 134 | 63140 m2 22 | 18910 m2 14 | 9010 m2 48 | 25380 m2 50 | 9840 m2

FO2 FO3

Open space configuration bridge no. cantilever no. hybrid no. roof no.

127

POST ANALYSIS - SUNLIGHT HOURS Assess the solar performance on open spaces of selected individuals The result of the solar analysis on the generated open spaces shows that although maximizing the sunlight hours on the open spaces is a fitness objective, the postanalysis results have many variations.

As the design objective is to maximize the area with green spaces, candidates that receive more than 5 hours of sunlight on at least 60% of the space will be prioritized.

Observation Although the first candidate has the maximum amount of area that receives high sunlight, it is not selected as it also has the maximum amount of area that receives the least amount of sunlight.

To find the right balance, we will compare the ratios of the area that receive high sunlight hours with the areas that receive low sunlight hours. Candidate 4 has the highest ratio. It will be given priority. 60% of the total area receives more than 7 hours of sunlight, while only 20% of the area receives less than 3 hours of sunlight during the period.

128

Design Development | Multi-level Ecology

Fittest individual - solar exposure

5

Gen.0-Ind.6 | FC1 fittest

Gen.19-Ind.3 | FC4 fittest

Maximize void volume total 107220 m2 0 hour 41520 m2 1-4 hours 22390 m2 5-8 hours 17430 m2 9- hours 25890 m2

Minimize shading on open space in summer total 62120 m2 0 hour 24810 m2 1-4 hours 11260 m2 5-8 hours 9910 m2 9- hours 16140 m2

Gen.16-Ind.5 | FC2 fittest

Gen.4-Ind.2 | Relative diff. rank 0

Minimize shadow on existing buildings total 63300 m2 0 hour 24350 m2 1-4 hours 14190 m2 5-8 hours 3820 m2 9- hours 16440 m2

total 86070 m2 0 hour 33330 m2 1-4 hours 17970 m2 5-8 hours 13390 m2 9- hours 20780 m2

Gen. - Ind. | FC

Fitness criteria

total open space area area with no sunlight 1-4 sunlight hours 5-8 sunlight hours 9-12 sunlight hours

Solar exposure configuration Gen.18-Ind.5 | FC3 fittest

Minimize shading on open space in winter total 63140 m2 0 hour 25420 m2 1-4 hours 9670 m2 5-8 hours 12409 m2 9- hours 15640 m2

Sunlight hour analysis Summer solstice 21st June 6:00-18:00 area with no sunlight 1-4 sunlight hours 5-8 sunlight hours 9-12 sunlight hours

129

POST ANALYSIS - SHADOW IMPACT TO EXISTING BUILDINGS Assess the percentage increase of shadow impact on the existing building of selected individuals This analysis is carried out to understand the impact that the generated open spaces have on the buildings on site.

As increasing the area of the results of the open space in the increase of shadow cast by them, this analysis aims to select a configuration of open space that corresponds to less than a 10% increase in shading compared to the current scenario. Individuals that achieve the desired open space area and create minimum shadow are prioritised.

Observation The result of the shadow analysis portrays that there is a minimum deviation in the shadow cast by the results and the existing scenario. There is an approximately 3-4% increase in the shading in all the selected solutions. This range of increase in shading is acceptable as our target is to keep the impact under 10%. Since all the selected individuals fall in this range, this criteria in evaluation can be disregarded.

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Design Development | Multi-level Ecology

Fittest individual - shadow analysis

+5%

0% -2% -3%

Gen.0-Ind.6 | FC1 fittest

Maximize void volume total 667305 m2 338700 m2 154935 m2 54435 m2 119235 m2

+3%

Gen.19-Ind.3 | FC4 fittest

Minimize shading on open space in summer total 667305 m2 330620 m2 151690 m2 56970 m2 128025 m2

0% -1% -2%

Gen.16-Ind.5 | FC2 fittest

Minimize shadow on existing buildings total 667305 m2 326065 m2 151715 m2 58260 m2 131265 m2

0% -1% -3%

+4%

0% -2% -2%

+4%

Gen.4-Ind.2 | Relaive dif. rank 0 total 667305 m2 336670 m2 153705 m2 52885 m2 124045 m2

Gen. - Ind. | FC

Fitness criteria

total open space area area with full shadow 9-11 shadow hours 5-8 shadow hours 0-4 shadow hours

Shadow analysis comparison Relative change Primitive +3%

0% -1% -2%

Gen.18-Ind.5 | FC3 fittest

Minimize shading on open space in winter total 667305 m2 324935 m2 159845 m2 53055 m2 129470 m2

Solution

+3%

0% -1% -2%

area with full shadow 9-11 shadow hours 5-8 shadow hours 0-4 shadow hours Shadow hour analysis Summer solstice 21st June 6:00-18:00

131

Primitive 9040 m2 4880 m2 4466 m2 905 m2

POST ANALYSIS - SHADOW IMPACT ON GROUND LEVEL Assess the percentage increase of shadow impact on the ground level of selected individual In this analysis, we aim to study the impact of the generated spaces on the ground level of the site. The result will be compared to the ground level shading imposed by the existing buildings to evaluate the impact of the open spaces.

The candidate that comprises of the minimum amount of spaces that are shaded for more than 5 hours during the summer solstice is prioritised.

Observation Candidate 5 performs the best in this analysis, as when compared to the shading cast by existing buildings, the result portrays a 2.3% increase in area that receives more than 8 hours of shadow and a 1.8% increase in the area that receives 5-8 hours of shadow.

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Design Development | Multi-level Ecology

Fittest individual - shadow analysis

9340m2 (+3.3%) 5186 m2 (+6.3%) 3965 m2 (-11.2%) 800 m2 (-11.6%)

Gen.0-Ind.6 | FC1 fittest Maximize void volume

9217 m2 (+1.9%) 5078 m2 (+4.1%) 4148 m2 (-7.1%) 848 m2 (-6.3%)

Gen.16-Ind.5 | FC2 fittest

Minimize shadow on existing buildings

9295 m2 (+2.8%) 5044 m2 (+3.4%) 4164 m2 (-6.8%) 788 m2 (-12.9%)

Gen.19-Ind.3 | FC4 fittest

Minimize shading on open space in summer

9285 m2 (+2.7%) 5092 m2 (+4.3%) 4103 m2 (-8.1%) 811 m2 (-10.4%)

Gen.4-Ind.2 | Relative diff. rank 0

Gen. - Ind. | FC

Fitness criteria

9251 m2 (+2.3%) 4967 m2 (+1.8%) 4209 m2 (-5.8%) 864 m2 (-4.5%)

Gen.18-Ind.5 | FC3 fittest

Minimize shading on open space in winter

Relative change of shadow on ground compared to primitive > 8 shadow hours 5-8 shadow hours 1-4 shadow hours 0 shadow hour Shadow hour analysis Summer solstice 21st June 6:00-18:00

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TEST EXPERIMENT 1 CONCLUSION Achievements and limitations Achievements The desired distribution of open spaces has been achieved that has satisfied the open space area requirement by increasing the current open space by 200% as well as the sunlight hour requirement, where 60% of open space receives sufficient sunlight.

Although the total area of the open spaces is more than what we aimed to achieve, the spaces have a minimal impact on the existing buildings. This is achieved by creating an evaluation hierarchy.

In this hierarchy, the solar analysis was given the maximum priority as it is essential for the planting strategy as well as human comfort on the open spaces while the shading analysis was given the least priority as all the selected individuals minimally impacted the existing urban fabric.

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Limitations A more in-depth evaluation of the existing structure of individual buildings may have increased the limitations of the open space distribution.

The units directly beneath the open spaces may receive insufficient sunlight. An alternate programme may be assigned to these units.

The selected individual affects a population of 1800 people. Giving priority to specific individuals could have considerably reduced this number. However, those individuals perform poorly in the remaining analysis.

Design Development | Multi-level Ecology

Gen.19-Ind.3 | FC4fittest, Average rank

Target

+200% open space area

60%

open space area that receives sunlight for planting

>10%

shadow impact to context

Performance Area of open spaces:

62,120 m2 | +240%

Number of spaces:

127 spaces

High sunlight hours area:

16,140 m2 | 26% of total area

Absolute shaded area:

24,812 m2 | 40% of total area

Shadow impact on existing context:

+4% full shadow area

Estimated affected population:

1800

135

TEST EXPERIMENT 2 - NETWORK GENERATION Ambition and design objectives Ambition

The aim of this experiment is to create an optimal network of the generated open spaces.

There can be a plethora of combinations in which these spaces can be connected. However, it is imperative to derive a strong connection logic for the network such that allows pedestrian commute along with green spaces, creates ample social opportunities and enhances urban ecology by creating a continuum of open space.

Design Objectives The desired outcome from this GA is to achieve a resilient network of interconnected open spaces that emphasises on programmes that require high connectivity. This can be achieved by breaking down the ambition into four fundamental design objectives.

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1. Increase the number of green spaces with direct access from places of high pedestrian flow, such as the wet market and public transport access points. This would create social hubs that are highly accessible to the public.

2. Higher pedestrian flow should be channelled through larger open spaces to increase social interaction while making the commute more pleasurable.

3. Connecting open spaces to enhance ecology.

Interlinking open spaces also links the programmes around the open space, thereby creating ecological heterogeneity.

4. Create a resilient network that provides alternate routes if certain links fail. Although a resilient network is considered inefficient with redundant links, it creates a stronger network system.

Design Development | Multi-level Ecology

More green spaces are directly accessible from public transit points and market

High pedestrian flow passing through large open spaces increases probability of social interaction

Enhancing ecology of the environment

Alternative routes if one node fails

High betweenness centrality value of routes passing through large open space nodes

Connect as many greenery nodes as possible

Increase connectivity of the network

Design Objectives

Experiment Objectives

Increase degree value of important programmes nodes

Important programmes Connected space

Size of open space: large

Connectivity: high

Open space

alternative road connected space

medium low small

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EXPERIMENT SET UP

In the following experiment, the result of experiment 1 will be used as primitive input. The primitive and the centroids of the generated open space comprise of the body plan in the GA. Each iteration of the GA will begin with seven start points, four of which will be fixed and three variables.

The range in which the start points connect to open space nodes is based on a span of 30 metres and an inclination of 18 degrees.

3.

Enhance accessibility to the nodes that correspond to programme priority by connecting them to maximum open space nodes.

The nature of the connection will determine the type of connection elements. There are three types of connection elements.

1.

Access points are created in the form of external or existing cores in the buildings, when starting nodes connect with vertically overhead nodes.

2.

Direct connections are created between open space nodes when they are within a 15 metres proximity with no obstructions.

3.

Pass-by connections are created when there are no nodes within span range, in which case these connections cut through existing buildings and act as medians between two open space nodes.

The fitness objectives in this experiment are: 1.

2.

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Minimize the impact on the existing build. Since pass-by nodes are medians between two open spaces, they are required to cut through existing buildings without adding any spatial value.

Connecting a maximum amount of open spaces directly makes the network to create a resilient network that can substitute for failure in certain nodes or edges

Design Development | Multi-level Ecology

Primitive & Body plan

Fitness criteria

Size of open space: Large Open space

Medium Small

Pass by node

FC 1: LESS IMPACT ON EXISTING BUILDINGS minimizing the number of pass by nodes

FC 2: CONNECTING OPEN SPACES maximizing the number of connected open spaces

Important programmes Connected space

FC 3: ACCESSIBILITY OF MAJOR PROGRAMMES maximizing the degree value at mass-transit and market nodes

Connection elements

d

d

d

d

angle < 18째 angle < 18째 angle < 18째 angle < 18째 distance < distance 15m < 15m distance < 15m distance < 15m

TYPE 1:

TYPE 2:

TYPE 3:

ACCESS POINT

CONNECTION BETWEEN OPEN SPACES

PASS-BY EXISTING BUILDINGS

139

PSEUDO CODE

The network generation begins with several starting points. These points are selected based on an access point hierarchy.

There are two ways in which the starting points are determined - fixed and variable. Firstly, the fixed starting points are assigned to important programmes that require high connectivity, mainly the wet market and the mass transit transport access points.

In the second scenario, the GA selects a set of existing open spaces or residue spaces as variable starting points. Every iteration will have a different set of variable points to allow the network to optimize.

In the beginning, each of the starting points evaluates its immediate surrounding to locate open space nodes within a specific range. This range is based on a span and an inclination angle that represents walkable gradient standard.

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The starting points will connect to all the open space nodes that are present in this range. If there are no open space nodes available in the range, each starting point connects to one pass-by node in range.

The open space and pass-by nodes will now act as the starting points and continue connecting to nodes within range.

This is a non-linear network, and the loop continues until two pass-by nodes are connected in each group, concluding the first stage of the network generation.

In stage two, the connected, open space nodes evaluate the presence of other open space nodes vertically above them. If present, the nodes will connect to the respective overhead nodes and begin connecting to the surrounding open spaces like in stage 1.

Design Development | Multi-level Ecology

Access Point Types and Hierarchy

PUBLIC BUILDING

RESIDUE SPACE

EXISTING OPEN SPACE

18o

25m

starting point no open space point in range

Connection w/ pass-by point in existing building

open space point in range

Connection w/ open space points in range

Legend connection constraints activated points connected open space point connected pass-by space point existing building axis created connection connected point becomes starting points

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EXPERIMENT RESULT Selected individuals for further analysis The following are the selected highest-ranking candidates that are corresponding to each of the fitness objectives.

The respective diamond graphs demonstrate that the three fitness objectives contradict each other.

In order to select the highest performing individual, design objectives will be prioritised.

The selected candidates are analysed and compared to identify the candidate that best suits the desired criteria.

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Design Development | Multi-level Ecology

Fittest candidate of fitness criteria

Gen.77-Ind.0 | FC1 fittest Minimize pass-by nodes

Gen.11-Ind.1 | FC2 fittest

Maximize area of connected open space

Gen.33-Ind.2 | FC3fittest

Maximize degree value to important programmes

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POST ANALYSIS - NETWORK ANALYSIS Comparison of high ranking individuals In the following evaluation, the selected high performing candidates are compared with respect to betweenness centrality, network structure graph and the connectivity of green spaces.

1.

Betweenness centrality is a measure of centrality based on the shortest paths. It shows how often an edge happens to be present close to the shortest path between an origin and a destination.

The result shows that although candidate 1 and 3 have edges with high betweenness, the areas corresponding to the high betweenness are restricted to one part of the site. While areas corresponding to edges with high betweenness in candidate 2 are distributed around the important programmes of the site, which is desirable.

2.

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The network structure graphs show that candidate 2 has the highest number of pass-by nodes, which is undesirable. However, candidate 2 also has the maximum number (89%) of spaces

connected which is important for the resilience of the network.

3.

In the third evaluation, the connectivity of large open spaces of the candidates is compared.

Candidate 1 has only 34 of large open spaces and low connectivity. Though candidate 3 has efficient connectivity, it has a lower number of large open spaces compared to candidate 2.

Candidate 2 has 51 open spaces with redundant links interconnecting them. This redundancy makes the network more resilient.

Design Development | Multi-level Ecology

Betweenness Centrality graph (people flow) Betweenness Centrality Low

High

Network structure graph

Connectivity of open spaces Size of open space:

1 Open space in the building

3000 m²

>1 Open spaces in the building

2200 m² 400 m²

Pass-by space

50 m²

Access point

5 m²

Large Medium Small Pass-by space Access point

Gen.77-Ind.0 | FC1 fittest

Minimize utilizing existing building

Spaces connected:

62%

Total no. of large open space:

34

Spaces connected:

89%

Total no. of large open space:

51

Spaces connected:

85%

Total no. of large open space:

42

Gen.11-Ind.1 | FC2 fittest

Maximize area of connected open space

Gen.33-Ind.2 | FC3fittest

Maximize connectivity to important programmes

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EXPERIMENT CONCLUSION Achievements and limitations Achievements The selected candidate comprises a resilient network of interconnected open spaces that emphasises on programmes that require high connectivity.

Studying the pedestrian flow and movement patterns of the population could have resulted in the development of a more dynamic system.

The result increases the number of green spaces connected directly to important programmes such as the wet market and public transport access points.

These programmes also have a high betweenness centrality value, improving their accessibility.

The GA simulation of network optimization does not converge due to the conflicting fitness objectives. The result of this is that the fittest individual belongs to an early generation - 11.

The larger open spaces have higher connectivity, channelling larger pedestrian flow through these spaces.

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Limitations

A more effective balance between redundancy and efficiency can be achieved such that the network is both resilient and resource-effectively.

Design Development | Multi-level Ecology

Gen.11-Ind.1 | FC2 fittest

Target Connect as many open space nodes as possible More direct open space connection to important programmes High betweenness centrality value of routes passing through large open space nodes

Performance Percentage of connected open space:

89%

Number of pass-by nodes:

65

Directly accessible spaces from important programmes: 7 Betweenness centrality value at market node:

high

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OPEN SPACE AREA AND HEIGHT - EXPERIMENT I EVALUATION OF SPACE GENERATED FROM EXPERIMENT I AND FEEDBACK EXPERIMENT

% of type by area 19% 18%

28% 35%

% of type by no.

46%

160

150

140

25%

19% 10%

Experiment I Gen.19-Ind.3 | FC4 fittest Maximize void volume

Bridge Cantilever Hybrid Roof

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20 | 17,940 m2 11 | 9,530 m2 27 | 14,430 m2 50 | 9,840 m2

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120

110

100

90

80

70

60

50

40

30

10

0

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Height (m)

20

Area (m²) 0

500

Design Development | Multi-level Ecology

500

1000

The above matrix organizes and plots the generated open spaces in experiment 1 according to their corresponding height and area.

As seen in the matrix, a majority of open spaces are located in 10m to 30m zone irrespective of size. This is because the location of open space that is in proximity to important programme is prioritized. Also the ramp restrictions limit the connections in this zone

1500

2000

The open spaces with the largest area are located higher up as compared to spaces with a smaller area.

This might create structural complications. This is a limitation of the open spaces distribution as high loads at higher levels would compromise on structural integrity.

In the next step, it is necessary to consider the limitations of existing urban fabric as this would help optimize the connection network as well as improve accessibility to local programmes.

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OPEN SPACE AREA AND SUNLIGHT HOURS - EXPERIMENT I EVALUATION OF SPACE GENERATED FROM EXPERIMENT I AND FEEDBACK EXPERIMENT

500

400

300

200

39%

24% 16%

21%

100

Sunlight Hours Area 0 1-4 5-8 9-12

41,520 22,390 17,430 25,890 0

150

Area w/ >5 sunlight hours

Experiment I Gen.19-Ind.3 | FC4 fittest

Area (m²) 0

500

Design Development | Multi-level Ecology

500

1000

The above matrix organizes and plots the generated open spaces in experiment 1 according to their area and the amount of area that receives more than 5 hours of sunlight.

A direct relation between the size of space and sunlight hours can be drawn. Smaller spaces receive lesser amounts of sunlight and vice versa,

1500

2000

As seen in the matrix, the open spaces that are generated at lower heights, receive lesser amounts of sunlight. This is both due to the built density at lower levels, and the size of open spaces. As most of the open spaces at higher levels are larger in size, they receive more sunlight. This is impractical due to structural limitations. If the open spaces at lower levels are larger, a hypothesis can be made and tested that they would receive more sunlight.

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ARCHITECTURAL ELEMENT

TYPE 1: ROOF

FACTOR

TARGET

TYPE 2: BRIDGE

TYPE 3: CANTILEVER

TYPE 1: ACCESS POINT

TYPE 2: CONNECTION

Solar exposure

Connectivity

Ventilation

Betweenness centrality

Shadow

Accessibility

Open space area

Physical limitation

+200%

•

Connect as much open space nodes as possible

60%

•

More direct open space connection to important programme

•

High betweenness centrality value of routes passing through large open space nodes

open space area have

>10%

shadow impact to context

+240%

open space area

66%

open space area have sunlight for planting

4%

shadow impact to context

89%

open space connected

7

Direct accessible spaces to important programme

High

betweenness centrality value at market node

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TYPE 3: PASS-BY

open space area

sunlight for planting

RESULT

TYPE 4: HYBRID

Design Development | Multi-level Ecology

EXPERIMENT I & II CONCLUSION Targets and achievements The result of experiment 1 shows that the three targets to achieve more than 200% of the existing open space area, 60% of which receives more than 5 hours of sunlight and to impose a less than 10% shading impact on the existing built space have been accomplished.

Similarly, the aims of experiment 2, which were to maximize connections, enhance people flow, and improve accessibility to important programmes have been achieved as well.

Experiment II creates an abundance of pass-by nodes. These are areas that are only wide enough to channel pedestrian flow and function as bridges. Connections like these are not ideal as they are not wide enough to hold programmatic character which is necessary for social value. Connections must be spatial and offer a range of activities or they would just function as the current pedestrian pathways on the ground level that often result in overcrowding.

As we are increasing the amount of open spaces, it is important to consider a water collection strategy to be able to sustain them.

The open spaces can potentially function as catchment areas that can channel the water to storage units.

The units directly beneath the open spaces may receive insufficient sunlight. An alternate programme may be assigned to these units. These areas may function as service floors or storage units and not residential units.

The success of the system cannot be evaluated by analyzing these experiments in isolation. It is imperative that the two experiments inform each other in order to develop a comprehensive system.

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Open space distribution

Integrated global scale system experiment

Network connection

Water storage tank distribution

Design Development | Multi-level Ecology

GLOBAL INTEGRATION EXPERIMENT Overview Although the two test experiments establish a co-dependency between the open space distribution and the network generation, the preliminary distribution of open spaces had no influence of the network. Steps taken after were mere improvements to the original open space configuration.

In order to achieve a result that is comprehensive as well as ‘Ecological’, the open spaces and the network must emerge simultaneously in symbiosis. Therefore, an ‘Integration experiment’ is conducted that is all-inclusive. The result of this experiment will potentially provide the opportunity to create connected open spaces that create interrelationships between existing programmes that were otherwise disconnected.

Additionally,the hydrological system is incorporated within this experiment by locating and determining capacity of underground water storage tanks.

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GLOBAL INTEGRATION EXPERIMENT Methodology This experiment integrates the open spaces generation experiment and the network generation experiment into one single experiment such that the previously separate experiments inform each other at every step in the experiment. Additionally, it also determines the size and location of the underground water storage tanks.

1. The integration experiment comprises of a core loop in which, an open space is created which is then linked to the next space. This is different from the test experiments where all the open spaces were first generated and then connected.

2. The spaces are connected according to an access point hierarchy. This hierarchy is based upon the priority of connecting the important programme existing on site. The centrally located market for instance is a programme that is designated to be the focus for the network generation. The MTR station are also prioritized in the network generation. Block access points are established in the experiment which are necessary to improve connectivity.

156

These access points determine the network hierarchy. The network hierarchy establishes a ranking based on the priority of the network connections, classifying the network connections into three categories: primary network, primary network branches and the secondary network.

External cores are created to increase connectivity to the elevated open spaces. These cores are created on existing open spaces on the ground level or in residue spaces between buildings.

3. As part of the water collection strategy, the location and size of the underground water storage tanks is determined in the experiment. These tanks can be potentially located under existing open spaces or under residue open spaces between built areas.

Design Development | Multi-level Ecology

Open Space Generation

Open Spaces generation

TYPE 1: ROOF

Network connection

TYPE 2: BRIDGE

TYPE 3: CANTILEVER

TYPE 4: HYBRID

Access Point Hierarchy

Residue space

Existing Open Space

Access Point Types Market (existing) Hierarchy

MTR station entrance (existing) Block access point (variable)

Water Tank Location

Residue space

Existing Open Space

Water tank location candidate

157

INTEGRATION EXPERIMENT SETUP Ambition

Body plan

The ambition of this experiment is to combine the previously conducted test experiments by creating the open spaces and the connection network simultaneously.

The experiment generates and distributes open spaces in the existing urban fabric while improving their accessibility by efficiently connecting the spaces to important programmes. The experiment also determines the location and size of water storage tanks on the site.

The body-plan for the experiment comprises of three main elements: 1. Point cloud in the existing building for connecting and generating open spaces. Points have been distributed through the buildings that when activated, will act as potential starting points of the network connections.

Target 1. To increase the open space area on site by 200% 2. To achieve at least 5 hours of sunlight on 60% of the open spaces 3. Create connections with high betweenness centrality values at prioritised access points (Market and MTR stations).

4. Minimize the difference in water storage capacity in underground storage tanks.

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2. Access points: There are 3 levels of hierarchy of access points that affect the network hierarchy. The market is classified the highest, followed by the MTR station exits, followed by block access points in the access point hierarchy.

3. Candidate points for water storage: The location for underground water storage tanks has limitations. It needs to be situated at a safe distance from building foundations. Potential points are identified under existing open spaces and residue spaces.

The GA produces 200 candidates, running for a generation count of 20, each of which comprises of 10 individuals.

Design Development | Multi-level Ecology

Primitive

Body plan

Connection possible connection point cloud Access Point Types Market (existing) MTR station entrance (existing) Block access point (variable) Water storage tank location candidate under the existing open space and the residue space

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FITNESS OBJECTIVES 1. Maximize sunlight exposure in Summer 2. Maximize sunlight exposure in Winter 3. Maximize betweenness centrality value around Market 4. Maximize the number of larger open spaces on the primary network 5. Minimize the difference in capacity of the water tanks The connection network generated is subcategorized in a hierarchy. This hierarchy determines which connections are generated first. The central linkage connecting the market and the station is regarded as the primary connection.

The branches of the primary network link the block access points to the primary connection. 10 nodes are selected more than 30 metres above in buildings that are in proximity to the primary network. These nodes represent the start points for the secondary network. The secondary network essentially connects communal open spaces on the higher floors. The open spaces that are not directly connected to the network are private spaces for the respective building.

160

Design Development | Multi-level Ecology

Fitness Criteria

FC 1: SOLAR EXPOSURE maximize solar exposure in summer FC 2: SOLAR EXPOSURE maximize solar exposure in winter

FC 3: ACCESSIBILITY OF MARKET maximize the betweenness centrality value at market node

Connected space Important programmes Connectivity: high low

FC 4: CONNECTING LARGER OPEN SPACE maximizing the number of connected larger open space

Size of open space: large medium small

FC 5: WATER STORAGE TANK minimizing the difference in the amount of water stored

161

PSEUDO CODE FOR OPEN SPACE GENERATION To begin with, the market access point is designated to be the starting node of the primary network.

From the first node, the second node is identified by selecting and connecting the closet building node, within 20m (maximum length of the connecting bridge) and the horizontal angle range of 18 degrees.

Once the connection has been generated, the next step is to determine the type of space. If the distance between the nearest building is greater than 20 metres, a cantilever-type space is created; if the distance is between 10 and 20 metres, a bridge-type is created and if the distance is less than 10 metres, a hybrid-type of open space is created. The node corresponding to the generated open space then becomes the start node and analyses its neighbours for the next potential second node.

This two-step process is repeated until the four MTR station exits are connected within 30 metres.

The branches of the primary network that connect the block access points to the primary central network are then created in a similar fashion, wherein the block access points act as multiple

162

starting points. The connection simulation of these branches ends when either the individual link reaches within 30 metres of the primary network or is unable to identify a â&#x20AC;&#x2DC;second nodeâ&#x20AC;&#x2122; within its range.

Lastly, to create vertical connections, 10 points are selected from buildings that are part of the primary network or its branches. Nodes that are vertically above the selected points at a distance of more than 30 metres are the new starting nodes. The loop in this case ends when there are no more buildings left to connect within the predefined range.

Design Development | Multi-level Ecology

Connection w/ the closest open space point in range

Hybrid type 0m-10m

Bridge type 10m-20m

Cantilever type 20m-

Legend 18o

constraints

20m

Connection constraints

Open space type constrains

163

EXPERIMENT RESULT Selected individuals for further analysis From the resultant set, 5 individuals that perform the highest in each fitness object are selected. These individuals are evaluated to arrive at the optimum individual that performs the best according to the prioritized objectives.

We can see from the results that the objective that maximises the number of spaces connected conflicts with the other objectives. The candidates that perform well in this objective, have an average performance in other objectives. For this reason, it is important to prioritise the fitness criteria. Giving lesser weight to FC4 will result in solutions that perform better in the other objectives. From the connection functionality perspective, it is not important for all the open spaces to be connected in the network. Disconnected spaces are important as they create privatized spaces that cater to specific communities.

As the synergy between connectivity and spatial quality is the prime requirement for the result, the individual that performs the best in sunlight hours and the betweenness centrality analysis will hold the maximum importance.

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As the four fitness objectives do not carry the same weight, our design decision at this stage will be to prioritise the objectives in order to select the desired result. The selected individuals will be further analysed and processed through multiple environmental evaluations, to gain insight into their performances and gather sufficient information for the selection of one individual for the final architectural process.

Design Development | Multi-level Ecology

Fittest individual 10 Individual 20 generation (total 200 individual)

1

Gen.15-Ind.6 | FC1 fittest

Maximize sunlight in summer

Gen.18-Ind.1 | FC2 fittest Maximize sunlight in winter

Gen.19-Ind.1 | FC4fittest

Maximize the number of connected larger open spaces

Gen.17-Ind.3 | FC5 fittest

Minimize the difference in the amount of water stored in each water tank

Gen. - Ind. | FC

Fitness criteria

Gen.18-Ind.0 | FC3fittest

Maximize betweenness centrality value at market

Fitness ranking chart FO1 FO5 FO4

FO2 FO3

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POST ANALYSIS - SUNLIGHT HOURS Assess the solar performance on open spaces of selected individuals Post experiment analysis is conducted on selected individuals based on sunlight hour analysis, betweenness centrality and water storage - cluster distribution. The criteria of sunlight hour and centrality analysis are selected because spatial quality and connectivity are the most important objectives of this experiment.

In the sunlight hour analysis, it is evident that the individual that comprises of the highest amount of spaces that receive more than 5 hours of sunlight is not the fittest, but the individual that comprises of the least amount of spaces that receive less than 2 hours of sunlight. The aim of this analysis is to select an individual that has minimum dark spaces as these areas are undesirable, lack function and spatial quality.

Observation Although the second candidate has the least area that receives no sunlight, it is not the individual that is selected as it also has the least amount of area that receives the maximum amount of sunlight.

To find the right balance, we compare the ratios of

166

the area that receive high sunlight hours (more than 5 hours) with the areas that do not receive sunlight.

Candidate 1 has the highest ratio. It will be given priority. 68% of the total area receives more than 7 hours of sunlight, while only 17% of the area receives less than 3 hours of sunlight during the period.

Design Development | Multi-level Ecology

Fittest individual - solar exposure

1

Gen.15-Ind.6 | FC1 fittest

Maximize sunlight in summer total 77952 m2 0 hour 19269 m2 1-4 hours 31947 m2 5-8 hours 18762 m2 9- hours 7974 m2

Gen.18-Ind.1 | FC2 fittest Maximize sunlight in winter total 73521 m2 0 hour 18369 m2 1-4 hours 30138 m2 5-8 hours 16347 m2 9- hours 8667 m2

Gen.19-Ind.1 | FC4fittest

Maximize the number of connected larger open spaces total 57093 m2 0 hour 11091 m2 1-4 hours 24057 m2 5-8 hours 14712 m2 9- hours 7233 m2

Gen.17-Ind.3 | FC5 fittest

Minimize the difference in the amount of water stored in each water tank total 63627 m2 0 hour 12861 m2 1-4 hours 28395 m2 5-8 hours 15885 m2 9- hours 6486 m2

Gen. - Ind. | FC

Fitness criteria

total open space area area with no sunlight 1-4 sunlight hours 5-8 sunlight hours 9-12 sunlight hours

Solar exposure configuration Gen.18-Ind.0 | FC3fittest

Maximize betweenness centrality value at market total 71442 m2 0 hour 15777 m2 1-4 hours 28839 m2 5-8 hours 15450 m2 9- hours 11376 m2

Sunlight hour analysis Summer solstice 21st June 6:00-18:00 area with no sunlight 1-4 sunlight hours 5-8 sunlight hours 9-12 sunlight hours

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POST ANALYSIS - NETWORK ANALYSIS Comparison of high ranking individuals The betweenness centrality (BC) post analysis shows that the individuals that have the highest BC value at the market, also possess a high BC value at the MTR stations, as well as a majority of block access points in proximity to the primary network. This is desirable as efficiently connecting these important programmes was the initial aim of the experiment.

Observation The result shows that although candidate 1 and 5 have connections with the highest betweenness, the areas corresponding to the high betweenness in candidate 5 are restricted to North-East areas of the site. While areas corresponding to high betweenness in candidate 1 stretch on both the Northern and Southern sides of the marketplace. This would contribute to the ease of North-South pedestrian commute on the site, therefore this candidate is prioritised.

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Design Development | Multi-level Ecology

Fittest individual - betweenness centrality

1

Gen.15-Ind.6 | FC1 fittest

Maximize sunlight in summer BC value at market: 50602

Gen.18-Ind.1 | FC2 fittest

Maximize sunlight in winter BC value at market: 35964

Gen.19-Ind.1 | FC4fittest

Maximize the number of connected larger open spaces BC value at market: 17898

Gen.17-Ind.3 | FC5 fittest

Minimize the difference in the amount of water stored in each water tank BC value at market: 42816

Gen. - Ind. | FC

Fitness criteria Betweeness centurality value at market

Betweenness Centrality graph (people flow)

Betweenness Centrality

Gen.18-Ind.0 | FC3fittest

Maximize betweenness centrality value at market BC value at market: 51094

Low

High Market Station and school Access point

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POST ANALYSIS - WATER TANK LOCATION Difference in water tank capacity The candidates show the open spaces that correspond to the water tanks, where water collected from the open spaces is stored in the respective tanks. Fitness objective 4 minimizes the difference between the size of these storage units. Considering the burden and management of each water storage tank, it is ideal to distribute the amount of rainwater evenly.

Observation Although candidate 5 performs the best in this analysis, the performance of candidate 1 comes in a close second. For arriving at the final result of the post analysis, candidate 1 given priority as spatial quality is a more important consideration as compared to the water tank specifications.

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Design Development | Multi-level Ecology

Fittest individual - Difference in water tank capacity

Gen.15-Ind.6 | FC1 fittest

Maximize sunlight in summer2 group1 25992 m group2 3432 m2 group3 23164 m2 group4 12749 m2 group5 14478 m2 group6 25543 m2

Gen.18-Ind.1 | FC2 fittest Maximize sunlight in winter group1 54967 m2 group2 22820 m2 group3 629 m2 group4 3951 m2 group5 6657m2 group6 52050 m2

Gen.19-Ind.1 | FC4fittest

Maximize the number of connected larger open spaces group1 41575 m2 group2 8183 m2 group3 22850 m2 group4 9215 m2 group5 37408 m2 group6 37642 m2

Gen.17-Ind.3 | FC5 fittest

Minimize the difference in the amount of water stored in each water tank group1 13073 m2 group2 2348 m2 group3 38983 m2 group4 50352 m2 group5 17925 m2 group6 14649 m2

Gen. - Ind. | FC

Fitness criteria

total open space area belong to group1 group2 group3 group4 group5 group6

Gen. - Ind. | FC

Gen.18-Ind.0 | FC3fittest

Maximize betweenness centrality value at market group1 20165 m2 group2 3575 m2 group3 15048 m2 group4 34589 m2 group5 26645 m2 group6 17398 m2

Fitness criteria Betweeness centurality value at market

Water collection configuration group1 group2 group3

group4 group5 group6

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Result

The selected result has achieved an open space standard of 3.7 m2 per person which is higher than the initial ambition. The high betweenness centrality at the marketplace portrays that there is a clear emphasis on connections between important programmes.

The water storage tanks are unvaryingly and efficiently distributed over the site and not concentrated in the lower end of the site, without the need to enable water flow against gravity.

Limitations Floors of existing buildings are utilized in creating the open space connections. In doing so, residences of approximately 1200 people are affected. This number could potentially be reduced if partial floor slabs are utilized in creating the spaces. In which case, the overall open space area would deplete.

In certain existing buildings, the units directly beneath the open spaces may receive reduced sunlight. An alternate programme may be assigned to these units.

Conclusion

Although the experiment is set up to have 5 fitness objectives, each of the objectives does not hold an equal hierarchy for the selection of the final result, as that would produce an average result that would have a mediocre performance in all scenarios.

As the essence of the project lies in creating an optimum network system and improving connectivity, the fitness objective that maximizes the betweenness centrality at the market node is given priority.

Evaluating the results, it is evident that the fitness objective maximizing the solar exposure.

Exposure during the summer contradicts the objective that maximizes solar exposure during the winter. However, the individuals that rank the highest in the fitness objective that maximizes solar exposure during the winter also ranks considerably high in maximizing solar exposure during the summer months. For this reason, the objective that maximizes the solar exposure during the winter has been prioritized to select the result.

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A more in-depth evaluation of the existing structure of individual buildings may have increased the limitations of the open space distribution.

Opportunities Through the result of this experiment, the urban fabric has transitioned from isolated point blocks that can only be associated with each other via ground level connections, to an integrated, threedimensional urban patch that has open spaces which have the potential to support diversified activities and sustain human culture. The network system creates the opportunity to introduce programmatic variation in the open spaces and to evaluate the inter-programme relationships.

Design Development | Multi-level Ecology

Gen.15-Ind.6 | FC1 fittest

Performance

Area of open spaces:

156,876 m² | +340%

Number of spaces:

148 spaces

High sunlight hours area:

32,115 m² | 25% of total area

Absolute shaded area:

13,290 m² | 8% of total area

Estimated affected population:

2100

Percentage of connected open space:

93%

Betweenness centrality value at market node:

24,812 m² | 40% of total area

Total area of open space cluster in each water tank: G1: 25,992 m² G2:3,432 m² G3:23,164 m² G4:12,749 m² G5:14,478 m² G6:25,543 m²

Achieved Target

+200%

open space area

High betweenness centrality value at market

Minimizing the difference in the amount of water stored in each tank

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Test experiment

Integration experiment

RESULT

+240%

open space area

66%

area receiving sufficient sunlight for planting

PERFORMANCE

High

betweenness centrality

Not Considered water tank location

value at market node

89%

open spaces connected

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+340%

64%

open space area

area receiving sufficient

High

6 water tanks

betweenness centrality

sunlight for planting

in the site

value at market node

65

pass-by nodes

93%

open spaces connected

0

pass-by nodes

Design Development | Multi-level Ecology

GLOBAL SCALE DESIGN CONCLUSION Taking into consideration the test experiment, the limitations carved a clear path for the integration experiment. The integrated experiment, achieves a better performing and a more coherent result as compared to the result of the test experiments.

The amount of open spaces are substantially more, with larger spaces at the lower levels. Although the reWsult of the test experiments generated more than 200% of the existing open space, the majority of the spaces were located at high altitude. This is undesirable as heavy spaces on high altitude compormises the structural integrity of the building. The integration experiment resolves this issue.

As the experiment creates and connects one space at a time, the access to separate blocks as well as important programmes is optimized. As the average height of the network is now lower, better ground level connections are established.

The underground water tanks store excess water during the summer months that is utilized for irrigation during the winter months making the open spaces hydrologically self sustainable.

Additionally, pass-by connections are completely eliminated, connecting buildings with larger spaces and not just narrow bridges.

This presents the opportunity to create spaces with character that can accommodate programmatic variation.

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Design Development | Multi-level Ecology

PROGRAMMATIC DISTRIBUTION In this chapter, the open spaces achieved by the integration result are assigned programme based on multiple factors. This is done by evaluating each open space based on the four factors i.e., network hierarchy, size of open space, betweenness centrality value and access point proximity. The four values that correspond to each open space are then overlaid and remapped. These remapped values are then correlated to characteristics that public programmes such as plazas and parks comprise of. The spaces that align with these characteristics are assigned these programmes.

This is important as in order to develop spaces of interaction and social mixing, the provided areas need to incorporate programmatic variation as well as inter-institutional integration, with smooth transitioning spaces from programme-toprogramme while offering an array of activities that promote people to occupy them. The provision of spaces does not necessarily imply that the space is apt for social mixing, civic participation and recreation. The next step towards achieving such spaces is assigning programme to the public areas.

The generated outcome of connected spaces of differentiated urban character have the potential to enhance social interaction, creating flexible spaces that can accommodate the ever-evolving trends of how we inhabit our cities. The differentiated character can be achieved by introducing programmatic variation through the spaces. Introducing spatial programme assigns function, activity and character to these connected spaces, providing the opportunity to establish co-dependency between programmes.

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SPATIAL EVALUATION PARAMETERS Hierarchy of factors affecting the programmatic distribution In the category of open space area, larger spaces are considered to be more public while smaller spaces are considered to be private communal spaces.

In the case of network hierarchy, a value from 1 to 5 is assigned to individual open spaces, 1 being the most private and 5 being the most public spaces.

Spaces adjacent to the primary network are most public, while the ones corresponding to the secondary connections are the least private.

In the category of betweenness centrality, spaces that are in proximity to high betweenness values are considered to be more public while open spaces with a low betweenness centrality values are considered to be less public.

Similarly, in the access point proximity category, spaces in proximity to important programmes such as the market and the MTR stations are assigned a high value on the â&#x20AC;&#x2DC;Publicness â&#x20AC;&#x2122; scale while spaces in proximity to the block access points are assigned a lower value. Spaces that are not directly connected to access points are not evaluated in this category.

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These values are then overlaid and a hierarchy is created for the four evaluation categories as each category does not hold the same weightage.

Design Development | Multi-level Ecology

Primary Primary Branch Secondary

Network hierarchy

Prioritizing parameters

Large Medium Small

Size of Open Space

20%

Prioritizing parameters

40%

Connectivity: Low

Betweenness Centrality Value Prioritizing parameters

10%

Market and MTR Station Block access point

High

Access Point Proximity Prioritizing parameters

30%

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PROGRAMME ALLOCATION Translation of remapped values into programme characteristics The values from the four evaluation criteria are remapped according to the predefined priority, assigning each space with a publicness value from 0 - 4.

The final step in the programmatic distribution is to correlate these remapped publicness values to local programme characteristics in order to allocate the corresponding programme to the open space. To do so, 5 programmes are selected and defined.

1. Plaza and Public square Plazas and public squares are the largest, most central public spaces. These spaces are situated in proximity to public programmes and at low altitudes as these spaces are key in holding and channelling pedestrians through the primary network.

2. Utilities/services, Restaurant Utilities, services and restaurant are mainly stores, shops, cafĂŠs and restaurants that comprise of public seating areas along their frontage. These spaces are scattered throughout the site, away from the central area in order to distribute pedestrian load throughout the site.

3. Parks and playgrounds Parks and playgrounds are public spaces that are situated mainly at lower levels with high connectivity to block access points. These are large spaces that facilitate pedestrian flow in the primary branches 4. Communal seating, small park Communal seating and small parks are situated at higher altitudes for more private usage. These spaces are situated away from the primary network and may be connected only by the secondary network.

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5. Private seating Private seating is situated at high altitudes away from the primary as well as the secondary network.

These are small intimate spaces used only by its adjacent residential community.

The programme is assigned to open spaces based on the remapped values that correlate to the spatial character requirement of the five types of public space. The five sets of programmes are thus distributed throughout the site for further analysis and local design.

Design Development | Multi-level Ecology

Each space has value for the factors

Network hierarchy Size of Open Space Betweenness Centrality Value Access Point Proximity

Remapped the value with the hierarchy

Publicness Value; 0-4

Publicness Value; 0, 1, 2, 3, 4

0

1

2

3

4 Public

Private

Evaluation parameters

Hierarchy parameters

Network hierarchy

20%

Size of Open Space

40%

Betweenness Centrality Value

10%

Access Point Proximity

30%

Correlation with the 5 programmes

Programme

0

1

2

3

4

Seating, private area

Communal seating, small park

Park, Playground

Utility/ services, Restaurant

Plaza, Public square

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SPATIAL PROGRAMME Types of local programme in public areas Result The programmatic distribution result shows that we have achieved an open space network system that comprises of diverse programmatic variation.

The programmatic variation creates the opportunity of engaging multiple actors to create a richer multi-layered environment. It also serves in extending out shared resources,amenities and services to a wider community. These spaces can create employment opportunities, leisure, learning environments, and other interactive spaces with blurred institutional boundaries.

Observations Assessing the result, it is evident that the number of spaces that contain the Plaza/public square programme is comparatively much lower as compared to the other programmes. The Plaza/ public square category correspond to the largest, most public spaces that are close to important programmes. These spaces cannot be more in number as their role within this system is limited

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to channel pedestrian flow to and from the market and the MTR stations.

Utilities, services and restaurants are destination programmes that are distributed throughout the site in order to reduce people concentration in the central area.

The parks and playgrounds situated at low altitudes are scattered throughout the site. These spaces are well connected to the primary network branches and are well accessible from block access points. This provides an opportunity for people from all age groups to utilize these spaces.

Communal seating, small parks and private areas are situated in areas away from the circulation networks as they are at higher altitudes. These are quiet intimate spaces away from the city bustle that perform well environmentally as the air is less humid and there is sufficient incident sunlight onto the spaces.

Design Development | Multi-level Ecology

Plaza, Public square

Quantity of spaces

Utility/ services, Restaurant

Programme

Seating, private area

Communal seating, small park

Park, Playground

Utility/ services, Plaza, Restaurant Public square Park, Playground

Public

Private Quantity Total Area

7

52

43

47

12

5123 m2

56294 m2

42597 m2

29382 m2

10122 m2

Communal seating, small park

Fig.43. (1 from top) Plaza, Public square Fig.44. (2) Utility/ services, Restaurant Fig.45. (3)Park, Playground Fig.46. (4) Communal seating, small park Fig.47. (5)Seating, private area

Seating, private area

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OPEN SPACES WITH PROGRAMMES

Sample cluster selection

Cluster Studies

Sky view factor Horizontal view factor Sunlight hour analysis

Local scale design

Local Area Zoning

Planting Distribution

DESIGN PROPOSAL

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Design Development | Multi-level Ecology

LOCAL DESIGN Overview In this chapter, the open space surfaces are designed locally based on a function allocation to open areas by locally zoning them. This is done by fist selecting clusters with distinct spatial characteristics on which the local design will be performed.

These clusters are then studied and analyzed based on spatial specifications, environmental analysis, pedestrian flow analysis, sky-view factor and horizontal view factor.

Using the cluster study, the open spaces on individual clusters are subsequently zoned based on their functional usage into planter area, lawn, pavement and area with designated programme.

With the result of the local zoning, the candidate for the final local design detail is achieved, on which the planting distribution experiment is conducted.

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Sample cluster1 Sample cluster2 Sample cluster3

Cluster Selection Spaces with distinct spatial characteristics The intent of selecting clusters is to typify combinations of their constituent spaces that are present throughout the site with some variation.

With the open space network generation at the global scale, the local scale design is carried out on clusters with varying spatial character. Multiple clusters are chosen as a single block may not comprise of the range of programmatic and functional variation that different spaces comprise of. The local scale design cannot be done on singled out spaces as evaluation of connectivity, inter-programme relationships and transitions can not be carried out on isolated spaces.

Three clusters are selected as samples. The three clusters have distinct spatial configurations, creating ranges of distinct inter programme relationships.

The extent of the selection is determined by considering the inclusion of various factors in the clusters.

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Involving areas with diverse programmatic variation, proximity to important programmes existing, the programme of its constituent open spaces, direct and indirect connection to the primary network and proximity to the predefined water storage unit.

The clusters are evaluated under a series of analysis, namely pedestrian flow, sunlight hour analysis, sky view factor and isovist. The information obtained from the evaluation process will be utilized to inform the final design.

Design Development | Multi-level Ecology

Sample cluster1

Sample cluster2

Sample cluster3

Building Programme

Residential

Residential

Office, Residential

Network belongs

Primary, Branch, Secondary

Branch, Secondary

Primary, branch, Secondary

BC value

High - Low

Low

High - Medium

Access point

Market, Block Access Point

Block Access Point

Block Access Point

Altitude from sea level

20-25m

22-26m

1-2m

Water tank belongs

Group3, Group6

Group6

Group4, Group5

Water tank

×

×

〇

Programme

Programme

Plaza, Public square Utility/ services, Restaurant Park, Playground Communal seating, small park Seating, private area

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Sample cluster 1 Overview This cluster comprises of the most centrally located block in closest proximity to the market and the MTR station exit. The open spaces on the cluster are key in facilitating pedestrian flow as it is part of the primary network.

Cluster 1 aids the connectivity of eastern apartment buildings to the central marketplace through a series of intermediate open spaces. As this cluster is directly linked to the market and the Mass Transit Railway (MTR) station, the connected open spaces are predominantly public and experience exceedingly heavy pedestrian flow throughout the day.

The open spaces on this cluster rank the highest in access point hierarchy and are key to the connectivity of the whole site. The open spaces closest to the ground level comprise of public squares, plazas and services. Spaces at higher altitudes are more private and serve as parks and communal sky gardens. This cluster comprises of the least amount of private and communal areas as its constituent spaces are highly public with programmes that are utilized by a large number of people.

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Design Development | Multi-level Ecology

Block Access point Market

25 0

5

m

15

Programme Plaza, Public square Utility/ services, Restaurant Park, Playground Communal seating, small park Seating, private area

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Catalogue of constituent open spaces in sample cluster 1 Cluster 1 is centrally located that holds and channels the highest pedestrian flow on site. In order to facilitate this flow, it comprises of large open spaces at lower levels. It is evident from the catalogue of the spaces, that some of the largest spaces that function as plazas and public squares are located around the 3rd or 4th floor. This where the boundaries of existing institutions of residential and office buildings begin to blur as the public areas are shared spaces between these institutions.

Around the public plazas and squares, services and utilities as well as restaurants and cafes are scattered at slightly higher altitudes that dampen the load from the plazas and create spaces of interest. These programmes have high accessibility as services need to be centralized for the ease of access to the neighbouring residential buildings.

This cluster comprises of parks and playgrounds at around the 15th floor as a sufficient amount of sunlight within this cluster can be achieved at these altitudes so that plantation can be carried out on them. Although some places at lower altitudes

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receive sufficient sunlight, there is not enough space for plantation as majority of the space is required for pedestrian movement.

Communal parks and private seating is the least as this cluster is highly public and has the least amount of isolated intimate spaces that can be used by secluded communities.

Design Development | Multi-level Ecology

Legend Sample-no.

Altitude from the ground Area of open space Network hierarchy BC value Programme

Sample-9 Altitude:73m Area: 1792m2 Secondary Network BC value: Low Playground, Sports facility

Sample-10 Altitude:77m Area: 819m2 Secondary Network BC value: Low Seating, Small Park

Sample-7 Altitude:79m Area: 1957m2 Secondary Network BC value: Low Playground, Sports facility

Sample-8 Altitude:50m Area: 1538m2 Private BC value: Low Seating, Private Area

Sample-5 Altitude:10m Area: 1058m2 Primary Branch BC value: Low Playground, Sports facility

Sample-6 Altitude:19m Area: 1792m2 Primary Branch BC value: Middle Shop, Restaurant

Sample-3 Altitude:19m Area: 904m2 Primary Branch BC value: Middle Shop, Restaurant

Sample-4 Altitude:15m Area: 1174m2 Primary Network BC value: High Plaza, Performance

Sample-1 Altitude:15m Area: 1524m2 Primary network BC value: high Plaza, Performance

Sample-2 Altitude: 17m Area: 1426m2 Primary network BC value: high Plaza, Performance

Programme Plaza, Public square Utility/ services, Restaurant Park, Playground Communal seating, small park Seating, private area

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Sample cluster 2 Overview This cluster is situated on the Western edge of the site, is the fur thest from the central market and MTR station and has the least amount of open space/ person in the existing scenario.

The predominant progr amme in this area is residential and since important public programmes are mainly East and central heavy, the character of open spaces is largely communal-private, which is very different from the disposition of other sample clusters.

Its constituent open spaces mainly comprise of parks and playgrounds with private communal spaces for residents of apartment complexes encompassing the spaces.

The connectivit y of cluster 2 demonstrates how previously isolated peripheral areas are now well woven into the multi-level network system.

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Design Development | Multi-level Ecology

Block Access point

25 0

5

m

15

Programme Park, Playground Communal seating, small park Seating, private area

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Catalogue of constituent open spaces in sample cluster 2 In contrast to cluster 1, the spaces on cluster 2 are limited to the residences that are part of the cluster.

However, since this area faces a lack of parks that can sustain large plantations, the park situated on the lower floors of this cluster is utilized by neighbouring block to the cluster as well.

The total open space area in cluster 2 is about half the area of cluster 1. The spaces in the cluster are mostly private or communal parks and seating.

These areas are smaller in size and are meant to accommodate lesser people.

The spaces are intimate areas, disconnected from branches of the primary network, granting privacy to its users.

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Design Development | Multi-level Ecology

Legend Sample-no.

Altitude from the ground Area of open space Network hierarchy BC value Programme

Sample-7 Altitude:63m Area: 797m2 Secondary Network BC value: Low Seating, Private Area

Sample-8 Altitude:68m Area: 1093m2 Secondary Network BC value: Low Seating, Private Area

Sample-5 Altitude:27m Area: 715m2 Primary Branch BC value: Low Seating, Small Park

Sample-6 Altitude:26m Area: 487m2 Primary Branch BC value: Middle Playground, Sports Facility

Sample-3 Altitude:31m Area: 1128m2 Primary Branch BC value: Middle Playground, Sports Facility

Sample-4 Altitude:35m Area: 909m2 Primary Branch BC value: Low Seating, Small Park

Sample-1 Altitude:23m Area: 1363m2 Primary Branch BC value: Middle Playground, Sports Facility

Sample-2 Altitude: 23m Area: 737m2 Primary Branch BC value: Middle Seating, Small Park

Programme Park, Playground Communal seating, small park Seating, private area

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Sample cluster 3 Overview Cluster 3 portrays the interrelationship of the existing building programme and the open space programme with the primary network.

This region comprises of the majority of corporate and commercial buildings existing on-site, which creates the opportunity to design open spaces that will perform as important transitions from purely residential areas.

The open spaces in the cluster provide services for its residents as well as the neighbouring areas. The most accessible open spaces are primarily shops and restaurants adjacent to a public plaza that is part of the primary network. Pockets of public parks scattered about the lower levels of the cluster while the spaces at higher altitudes are smaller communal parks that cater to the neighbouring residences.

This selected cluster also comprises of an underground water storage tank.

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Design Development | Multi-level Ecology

Block Access point Existing Open Space Water Tank

25 0

5

m

15

Programme Plaza, Public square Utility/ services, Restaurant Park, Playground Communal seating, small park

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Catalogue of constituent open spaces in sample cluster 3 The spatial programmes of this cluster are similar to that of cluster 1, however their function varies. It comprises of some of the largest public spaces on site. Sample spaces 1-6 are situated at lower levels with a minimum level difference and hence act as a single connected space.

This is important as this section is a part of the primary network and channels high pedestrian flow.

It connects the North-East MTR exit to the central market and the rest of the site.

This cluster comprises of buildings corresponding to multiple institutions namely, residential, commercial and office. The chain of spaces also stitches the institutions together, imitating conditions of a ground level plaza at a higher level.

The three residential skyscrapers are connected at higher levels with communal park and a secluded seating area that perform well environmentally and provide a wide isovist.

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Design Development | Multi-level Ecology

Sample-9 Altitude:82m Area: 367m2 Secondary network BC value: Low Seating, Small Park

Legend Sample-no.

Altitude from the ground Area of open space Network hierarchy BC value Programme

Sample-7 Altitude:23m Area: 648m2 Primary Branch BC value: Low Shop, Restaurant

Sample-8 Altitude:82m Area: 1122m2 Secondary Network BC value: Low Seating, Small Park

Sample-5 Altitude:23m Area: 924m2 Primary Branch BC value: Middle Playground, Sports Facility

Sample-6 Altitude:24m Area: 698m2 Primary BC value: Middle Playground, Sports Facility

Sample-3 Altitude:24m Area: 830m2 Primary network BC value: high Playground, Sports facility

Sample-4 Altitude:21m Area: 1010m2 Primary branch BC value: middle Shop, Restaurant

Sample-1 Altitude:19m Area: 1350m2 Primary network BC value: high Plaza, Performance

Sample-2 Altitude: 25m Area: 1575m2 Primary network BC value: high Shop, Restaurant

Programme Plaza, Public square Utility/ services, Restaurant Park, Playground Communal seating, small park

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Connection Analysis Connection step visualization using J-graphs The J-graphs show which spaces are connected to each other and what network hierarchy the connections fall under. This evaluation is conducted at each access each access point in the cluster.

All the spaces created are first numbered and catalogued. The starting point of the graph in each cluster is the block access point of the cluster connecting higher spaces to the ground level. The spaces that are directly connected via ramps or staircases are juxtaposed on the graph.

The connection with solid stroke represent direct connectivity i.e., spaces that are directly accessible to pedestrians without the need to change levels vertically through a core. The connections with dotted lines represent vertical connections via cores which are intended to me minimized.

This representation helps in understanding how these spaces are connected and aids in visualizing the access point linkage of the multi-level open spaces.

At the local scale the graph will help determine spaces which are vertically connected and are less than 2 floors apart. These spaces can be connected not only by lifts but also by stairs. This data is important for the further pedestrian simulation as the movement patterns are subject to all possible connections of the three dimensional cluster.

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Cluster 1

Design Development | Multi-level Ecology

Cluster 2

Cluster 3

~

Access point

No.

Space name Primary connection Primary branch connection Secondary connection Vertical connection

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SPATIAL EVALUATION Sky View Factor A Sky View Factor (SVF) represents the ratio at a point on the open space between the visible sky and a hemisphere centred over the analyzed location.

A high sky view factor of a space implies that the space is more open-to-sky with fewer highrises or alternate obstructions in its direct vicinity.

Studying the SVF is essential since it is a measurement that can be used as a proxy for radiation, which influences air temperature and other related weather phenomena.

The sky view is also a factor of the altitude at which the open space is situated. Spaces at higher altitudes predominantly have a higher sky view factor due to the lesser built density.

As Cluster 1 is centrally situated and is most densely packed by surrounding buildings, spaces on lower altitudes are the least open-to-sky.

Programmatically, larger spaces at lower altitudes that can withstand high structural loads and that

202

have a high sky view factor can function as dense parks and open terraces.

The analysis exhibits that spaces at higher altitudes in all three clusters have higher spatial quality due to the higher sky view. However, this does not imply thermal comfort as spaces that have high sky view may not receive high amounts of sunlight and vice versa.

Design Development | Multi-level Ecology

Sky view factor

Sample cluster1

Sample cluster2

Sky view percentage

Sample cluster3

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Horizontal view factor An isovist is the unobstructed view or the set of all points visible from a given vantage point in space and with respect to an environment. Quantifiable measures of isovists are important as spaces with higher isovists (views) are considered to have higher spatial quality.

This is especially important in the ultra high density context of Hong Kong as buildings are crunched wall-to-wall with a minimal scope for avid views and vistas.

As the north of the site looks at the harbour and the bay with the south looking at the mountain range; not utilizing the scenic views for spatial design would be a missed opportunity.

Analysing the results, it is evident that the spaces that perform the best in the isovist evaluation are either situated adjacent main roads, overlooking the linear vista formed by existing roads or at higher altitudes since the built density reduces with altitude. The steep slope of the site factors in the isovist as well, providing higher levels of clear isovist on the mid to high floors on the north facing spaces

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whereas just the higher floors on the south facing spaces.

The distinct isovist values contribute in diversifying local programme as this directly affects the function and performance of the space. For instance, spaces that have an unobstructed view of the harbour, the mountains or an alternate vibrant open space must enable its users to capitalize on such views.

This can be done by providing seating, shading and viewing galleries that spill away from walkways.

Vegetation of the area may also be reduced in order to accommodate the unobstructed view.

At the local design stage, the spaces that have the highest horizontal view factor will be used to accommodate programme in which the crowds gather to capitalize on the view.

Design Development | Multi-level Ecology

Horizontal view factor

Sample cluster1

Sample cluster2

Horizontal view percentage

Sample cluster3

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Solar Analysis Sunlight hour analysis is conducted on the three clusters to identify open spaces that receive sufficient sunlight seasonally as there is a substantial change in sun-path through the seasons.

This analysis is essential to carry out the planting distribution and analysis of the results will also be translated into the local design as local activity is a factor of the sunlight intensity.

Locally, the spaces that receive high sunlight will be prioritized to accommodate maximum programmes that require outdoor open to sky gathering space or seating.

As there is a substantial shift in sun path from summer to winter months, there is a significant shift in the spaces that receive high sunlight. Due to this shift, different open to sky spaces will be thermally comfortable during different times of the year.

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Design Development | Multi-level Ecology

Summer solstice 21st June 6:00-18:00

Winter solstice 22nd December 6:00-18:00

Sample cluster1

Sample cluster1

Sample cluster2

Sample cluster2

Sample cluster3

Sample cluster3

Sunlight hour

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SAMPLE CLUSTERS

Subdividing spaces

Planting Zone by solar analysis

Pavement and Lawn area by pedestrian simulation

Overlaying the 2 results

Local Area Zoning

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Design Development | Multi-level Ecology

LOCAL AREA ZONING Overview Before approaching the local design, it is important to understand how the multi-level spaces perform at that scale. To do so, the spaces are first zoned according to planter, lawn, pavement and area with designated programme.

The open spaces are first subdivided into a lattice grid on which the zoning is conducted. The size of the grid varies with the altitude as it is a factor of the maximum plant load that the structure can withstand.

A sunlight hour analysis is carried out to identify areas suitable for planters and lawns. Subsequently, pedestrian movement patterns are mapped through the spaces.

The movement patterns from the pedestrian simulation identifies the complete area through which pedestrian mobilization takes place. This area comprises of the paved and the lawn area.

Overlaying the results from the sunlight hour analysis and pedestrian simulation, gives us the zoning result. The local design detail is developed on this result of the local zoning.

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LOCAL AREA ZONING SETUP Type of zoning and subdividing space The local zoning is devised to distinguish and divide the open spaces into four categories i.e., planter area, lawn, pavement and area with designated programme. The planter area is where the trees and shrubs are planted. The lawn and paved area facilitates peopleâ&#x20AC;&#x2122;s movement through the spaces, providing space to meander or halt as well. The remainder space is the area with designated programme, where the primary activity of the previously allocated programme takes place.

The surface of the open space are first subdivided.

From the calculation of the structural load limitations of the multi-level open spaces, it is evident that the load bearing capacity of existing buildings reduces with increasing altitude. Due to this, the planting distribution algorithm is designed with respect to the overhang and load limitations of the corresponding space.

With these distribution restrictions, it is hypothesized that smaller trees with lesser self, soil and water loads will be allocated to spaces at higher altitudes while larger trees with higher loads will

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be distributed among spaces at lower altitudes. To enable this, with a regulated vegetation density, grids of various cell sizes are superimposed on the open spaces. The grid cell sizes are determined by the maximum tree size corresponding to the structural capacity of the space.

Design Development | Multi-level Ecology

Types of zoning

Planter Area

Lawn Area

Pavement area

Designated programme

Subdividing space

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PLANTING AREA - SUNLIGHT HOURS Assess the solar performance on open spaces for vegetation The aim of this step is to determine the planting area of the cluster. The planting area is the complete public area that is capable of sustaining plantation throughout the year.

The solar analysis is carried out during the summer and the winter solstice. This is done as the two time periods portray the polar extreme shifts in the sun path. With the result of the analysis, we can accurately determine the range of areas that receive a minimum amount of sunlight.

The region of feasible plantation is first identified by extracting the area that receives more than 3 hours of sunlight everyday, all year long. This step is important to rule out spaces that receive high sunlight (more than 5 hours) during certain months and receive virtually no sunlight during alternate months. The resultant area in cluster 1 receives at least 3 hours of sunlight all year long, of which about 75% of the area receives more than 4.5 hours of sunlight.

This planting zone acquired can potentially substitute and sustain lawns and planters. The lawns are

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spaces for people to meander while planters are areas where trees and shrubs are planted.

Design Development | Multi-level Ecology

Solar analysis

Sunlight hour analysis Summer solstice 21st June 6:00-18:00

Sunlight hour analysis Winter solstice 22nd December 6:00-18:00

Planting area

Planting Zone Sunlight hour > 3 hours on Summer solstice and Winter solstice

Open Ground Zone

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PEDESTRIAN SIMULATION SETUP The aim of the pedestrian simulation is to determine the area through which pedestrians commute in the public spaces. This area is composed of the paved area and the lawn area.

These areas are obtained by extracting the movement patterns from the pedestrian simulation. The spaces where the pedestrian patterns overlap with the plantation zone are designated to be areas with lawns while the areas where the pedestrian pattern overlaps with the open ground zone are selected to be pavements.

The setup of the pedestrian simulation is a factor of inputs such as the population entering and exiting the spaces on the cluster, population affected by destinations such as building cores, local programme attractions like parks and public squares and the three dimensional topography as the base surfaces itself.

The first step is to collect background data. The data of the population exiting specific MTR and bus stations hourly is obtained from the HK

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Transportation website. Based on the specific MTR exit used by this population, an estimation can be made on the percentage of the population entering the cluster. From this number, the amount of people entering cores of the cluster buildings can be estimated by the approximate resident population of the particular building.

The next step is to establish the physical domain for the simulation. The boundary conditions of the three dimensional open space are defined including the entry and exit gates. Attraction points are set up with varying thresholds of attraction depending upon the programme of the corresponding space.

Finally, the rules for the agents to manoeuvre through the space are defined and programmed. This includes defining the percentage of agents that enter an open space, exit the space, end their journey at the core or continue the journey to the next space.

Design Development | Multi-level Ecology

Input value

Total population; 500 Access point threshold Market access point

30m

Connections b/w spaces

20m

Building cores

10m

Attraction threshold Plaza

20m

Restaurants and services

15m

Parks

10m

Setup Entry and Exit points

Attraction (Programme)

Access point

Plaza

Access radius 20m

Connections b/w spaces

Shop

Access radius 10m

Core of the buildings

Park

Access radius 5m

Park

Park Park

Plaza Park Shop Plaza

Shop Shop Plaza

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PEDESTRIAN SIMULATION RESULT Conclusion With the result of the pedestrian simulation the most frequented paths taken by the agents are extracted.

These will form the paved and the lawn area through the open spaces. The area specific pedestrian density is also extracted, with which the width of the pedestrian pavement and lawns can be determined.

The configuration of the pathways is not intended to provide ‘shortest paths’ to commute from programme-to-programme, rather an opportunity for people to meander through the spaces.

The agent’s walking speed reduces when it enters the threshold of the attraction point. The speed also reduces when the agents approach sharp turns. The crowding within a certain space is a factor of these conditions as well.

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Limitations The input population is approximated and the effect in crowding could be scaled up or down based on the change in input population.

The tool enables the designer to partially simulate human behaviour and the decision making ability.

Similar to most simulation tools, decision inputs such as wait time and variation in walking speeds are largely approximated.

The pedestrian simulation is run for the same analysis period on all spaces in all clusters i.e. during the rush hour of a midweek day. This may be an accurate period to gauge the maximum pedestrian density through public spaces. However, this time frame may not accurately justify the usage of spaces of leisure, and usage data for these spaces may be required through different time periods to accurately setup the simulation.

Design Development | Multi-level Ecology

Result

Sample cluster 1

Sample cluster 2

Sample cluster 3

Result overlay with setup

Park

Enter and Exit point

Park

Access point

Park

Plaza

Core of the buildings

Park Shop Plaza

Shop Shop Plaza

Connections b/w spaces

Attraction Plaza Shop Park The number of agents pass through High

Low

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LOCAL AREA ZONING RESULT Overlaying the results of sunlight analysis and pedestrian simulation Overlaying the result of the pedestrian simulation with the planting zone, the overall result of the zoning is achieved. The spaces where the pedestrian patterns overlap with the plantation zone are designated to be areas with lawns while the areas where the pedestrian pattern overlaps with the open ground zone are selected to be pavements.

The spaces that remains in the planting zone after the lawn area is determined is designated to be the planter area where the trees and shrubs are planted.

The remainder of the spaces after the categorization of planter area, lawn area and paved area constitutes of the programme previously determined.

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Design Development | Multi-level Ecology

Overlaying the results

Pedestrian Simulation

Planting Zone by solar analysis

Local area zoning result

Subdividing Grid

Pedestrian Flow Planter Area Lawn Area Designated Programme Pavement

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PLANTING DISTRIBUTION SETUP Post zoning analysis of the result The parameters for the vegetation distribution are based on the following factors: 1. Area that receives sufficient year-long sunlight capable of sustaining plantation. As the plants that are planted on the open spaces are evergreen, it is imperative that they receive ample sunlight year long.

Due to the seasonal shift in sun-path, there are spaces that receive high sunlight during certain months and are completely shaded during other months. Spaces that receive year-long sunlight are prioritized.

2. Structural limitation of the open space based on altitude, cantilever span and assumed beam depth.

3. Ease of water flow to the plants. Plants that require higher quantities of water are not planted at high altitudes to reduce the energy it takes to pump water and also reduce load on the structure.

4. Shading requirement of spaces. The edges of a majority of spaces face the Northern summer sun while South facing edges face the winter sun.

Due to this, taller trees with more extensive canopies are planted on the Northern periphery in order to block direct incident sunlight during summers while shorter trees are planted on the Southern periphery to allow incident sunlight during the winters.

In the planting strategy, steps are taken to introduce vegetation diversity on the open spaces, while simultaneously maximizing the amount of plantation adhering to the restricting parameters. This is because biodiversity boosts ecosystem productivity where each species, no matter how small, has an important role to play. Greater species diversity ensures natural sustainability for all life forms.

This is achieved by populating the unit cells with trees that comply with the spatial requirements of the area that the unit cell is located in. In this process, diversity is ensured by not planting trees of the same species

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adjacent to one another. Computationally, plants are packed within the unit grids to maximize the number of trees that the structure can withstand.

The hypothesis for setting these conditions is that lower levels will comprise of fewer but larger trees, which would create space for pedestrian flow and public activity; while higher levels would be densely populated with smaller trees, that would create quiet intimate spaces for residential communities to enjoy.

Design Development | Multi-level Ecology

Species Parameters Functional Parameters

Essential Parameters Climatic Parameters 2.5

2.5

4.0

2.5

4.0

2.5

4.0

4.0

2.5

4.0

4.0

2.5

Drought Drought Drought tolerant tolerant Drought tolerant Height & soil volume Height Height & soil & Height soil volume Sunlight volume & soilhour volume requirement Sunlight Sunlight hourhour Sunlight Height requirement requirement &hour soil requirement volume Wind tolerance Height &Wind soil Sunlight Wind volume tolerance tolerance hour Windrequirement tolerance ShadeSunlight cast hourShade requirement Shade cast Wind cast Shade tolerance cast tolerantWind tolerance ShadeBiodiversity cast -high(6m)

-high(6m) -high(6m)-high(6m) -more than 6 hours-more -more thanthan 6-more -high(6m) hours 6 hours than -more 6 hours than 10m/s -high(6m) -more -more than -more than 10m/s -more than 10m/s than 6 hours -high 10m/s

-midium(4m)

HEIGHT -low(2m)

tolerant Biodiversity Shade Biodiversity cast Drought Biodiversity

-more than -high 10m/s -high-high-high

-midium(4m) -midium(4m) -midium(4m) -less than 6 hours -less-less thanthan 6 hours -less -midium(4m) 6 hours than-less 6 hours than 10m/s-midium(4m) -less-less than -less than 10m/s -less than 10m/s than 6 hours 10m/s -middle -less than-middle 6 hours -middle -less than -middle 10m/s-moderate -less than-moderate 10m/s -moderate -middle -moderate

& -low(2m) SOIL VOLUME -low(2m) -low(2m)

High [6m] Medium [4m] Low [2m]

Setup

-more than -high 6 -high hours -more -high than 10m/s -high

SUNLIGHT HOUR -low(2m) REQUIREMENT

-500kg/m2 -500kg/m2 -500kg/m2

-low TOLERANCE

> 10m/s < 10m/s

> 6hrs < 6hrs

Height & structuralHeight limitation Height & structural & Height structural limitation & structural limitationlimitation -500kg/m2

-low(2m)WIND

Height Sunlight & hour structural analysis Sunlight limitation Sunlight Height hourhour Sunlight &analysis structural analysis hourlimitation analysis -500kg/m2

-low-low

-low -low -low-low -low-low DROUGHT TOLERANCE

Drought tolerant Biodiversity

-high

-high

-high

-middle

-moderate

-moderate

-low

-low

-low CAST SHADE

BIODIVERSITY

high low

high low

Biodiversity

high low

DistributionWindMethod velocity

Wind velocity Sunlight hour Wind analysis Wind velocity velocity Wind Sunlight velocity hour analysis

Wind velocity

-500kg/m2

Tree packing in the grid

r4

r3 Planter area

r1 r2 r7

Input Tree name Tree spread radius ; r Tree height ; h

r5

r6

r: Tree spread radius

Output Cylinder with the radius and height of the trees that are distributed

Distribution Objectives 1. Maximizing the diversity of the species 2. Maximizing the number of trees within the limitation of planting strategies

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PLANTING DISTRIBUTION RESULT - CLUSTER 1 It is clear with the implementation of the vegetation and the zoning of spaces that the three clusters have distinct spatial character.

As cluster 1 is centrally located in the area with the highest built density, only few open spaces on the lower floors receive sufficient sunlight to sustain plantation. Larger trees are planted in the areas that do receive sufficient sunlight as these spaces can withstand higher loads.

These active public spaces have maximum open ground as these comprise of public plazas serving both the residential as well as the office buildings in the vicinity. The main circulation route leading to the market is a part of these public spaces.

The higher levels of this cluster are more densely populated with greenery as these spaces receive more year long sunlight as compared to lower levels.

Although more in number, these trees exert a smaller load onto the structure. These are intimate spaces that cater to the adjoining residential buildings, cutoff from the public spaces and network connections.

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The trees are sound and moisture absorbing and also provide privacy to residential units from communal areas.

Design Development | Multi-level Ecology

Result Data Number of species

46

Higher range altitude Tree height range

0.5m - 3.0m

Tree spread radius range

0.5m - 1.4m

Middle range altitude Tree height range

0.5m - 5.5m

Tree spread radius range

0.5m -1.7m

Higher range altitude

Lower range altitude Tree height range

0.5m - 7.5m

Tree spread radius range

0.5m - 4.0m

Planting distribution result

Middle range altitude

Lower range altitude

r: Tree spread radius

h: Tree height

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PLANTING DISTRIBUTION RESULT - CLUSTER 2 As cluster 2 belongs to the area that has the least built density out of the three clusters, open spaces at all levels receive abundant sunlight to sustain plantation. The majority of open areas in this cluster are intimate communal spaces, disconnected from the branches of the primary network.

The playground on lower floor has dense plantation on its periphery such that there is maximum open ground in the middle for activity. As it is the largest within a 5 block radius and is used by the residents that fall within this range, it is important to maximize the active space.

Spaces at higher altitudes are densely populated with shrubs and short trees as the spaces receive substantial sunlight and the plants exert a smaller load onto the structure due to a low soil depth requirement.

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Design Development | Multi-level Ecology

Result Data Number of species

44

Higher range altitude Tree height range

0.5m - 3.0m

Tree spread radius range

0.5m - 0.8m

Middle range altitude Tree height range

0.5m - 5.0m

Tree spread radius range

0.5m -1.3m

Higher range altitude

Lower range altitude Tree height range

0.5m - 7.0m

Tree spread radius range

0.5m - 3.5m

Planting distribution result

Middle range altitude

Lower range altitude

r: Tree spread radius

h: Tree height

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PLANTING DISTRIBUTION RESULT - CLUSTER 3 This region comprises of the majority of corporate and commercial buildings existing on-site, which creates the opportunity to design green open spaces that aid users to have meaningful interactions and to form associations beyond work boundaries.

It is visually evident that the plantation density increases with altitude. This is not only because of lack of sunlight but also due to the fact that these spaces comprise of the primary pathways that require clear space and cannot be vegetated. However, this cluster disproves an initial hypothesis that if a cluster would have a large amount of circulation area, it would comprise of scarce plantation. As cluster 3 comprises of low-rise buildings, it receives high sunlight on the lower levels as well. Due to this, the cluster has both high circulation space as well as plantation.

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As sunlight is abundant and the requirement for pathways is scarce, the three connected high altitude open spaces are capable of accommodating dense greenery. These spaces are communal parks and seating with reduced accessibility that cater to the three high density residential buildings.

Design Development | Multi-level Ecology

Result Data Number of species

52

Higher range altitude Tree height range

0.5m - 3.5m

Tree spread radius range

0.5m - 1.5m

Middle range altitude Tree height range

-

Tree spread radius range

-

Higher range altitude

Lower range altitude Tree height range

0.5m - 6.0m

Tree spread radius range

0.5m - 4.5m

Planting distribution result

Lower range altitude

r: Tree spread radius

h: Tree height

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CONCLUSION Comparing the results of the three clusters, we can say that higher the people flow in an area results in higher paved area, in-turn resulting in lesser plantation. The areas with the maximum amount of trees are spaces that perform well environmentally, i.e. receive more than 3 hours of sunlight every day of the year and have minimum pedestrian flow through them.

As cluster 1 is situated in the most densely packed area, the large spaces at lower levels have both poor environmental performance as well as high pedestrian flow through them. Due to this reason, pavements are allocated to the majority of the area in this cluster.

As cluster 2 is situated in an area with lesser built density and its constituent spaces have minimum pedestrian flow, the cluster comprises of the highest Trees to area ratio. The majority of the plants are however short trees and shrubs as mainly spaces at higher altitudes can sustain plantation throughout the year.

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Cluster 3 has the maximum lowrise building compared to the other clusters. Due to this, lower public spaces have considerably high environmental performance as compared to cluster and in-turn can sustain more plantation.

Design Development | Multi-level Ecology

Sample cluster1

Sample cluster2

13984 m2

7229 m2

8524 m2

30: 12: 20: 38

44: 22: 15: 18

50: 26: 10: 14

Plant diversity (species)

46

44

52

Tree spread radius range

Higher Altitude:0.5m -1.4m Middle Altitude:0.5m-1.7m Lower Altitude:0.5m-4.0m

Higher Altitude:0.5m-0.8m Middle Altitude:0.5m-1.3m Lower Altitude:0.5m-3.5m

Higher Altitude:0.5m-1.5m Middle Altitude:Lower Altitude:0.5m-4.5m

Total Area Local Area Zoning Ratio Planter: Lawn: Pavement: Programme

Sample cluster3

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6 Design Proposal

231

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Design Proposal | Multi-level Ecology

DESIGN TRANSLATION Overview The aim of the design translation is to use the information obtained from the evaluation process to inform the local design.

An important aspect of the local design is to enhance the relationship between the existing structure and proposed open spaces, which are essentially extensions of existing floor slabs. The design must enhance social interaction, for people living and working in our modern cities, which is the fundamental objective.

The architectural principle of open ground creates a multilayered fabric which can generate spaces of differentiated character. While some spaces may capitalize upon higher frontage values and open-to-sky aspect, other spaces that fall under the existing floor slabs have the potential to accommodate programmes of community service or that foster emerging forms of art, creating opportunities for multi-generational interaction.

In order to create spaces of interest where people gather, surface level changes are brought upon the public spaces.

The level changes create three dimensional morphologies that are incorporated as seating units, steps for accessibility, planters and pedestals. The inclusion of these elements in the design drive the intended activity of the public space.

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High

High

Low

Low

Sky view factor

Horizontal view factor

SPATIAL EVALUATION - CLUSTER 1 Quality of open spaces A horizontal view analysis, sky-view analysis and a pedestrian flow analysis is conducted in addition to the previously run solar hour analysis in order to understand the spatial quality of the series of public spaces. The thickness of the arrows in the adjacent diagrams are proportional to the people flow density of that area.

This analysis is conducted in order to create three dimensional morphological change to the surface of the open spaces, that would assist the activity and the programme of the public space.

In cluster 1, due to the high pedestrian flow through the spaces at low altitudes in series 1, seating may be provided in areas that have a high horizontal view factor. This would provide a space for groups of people to gather. As this area interlaces residential and office institutions, it would serve as a shared leisure space.

Since the spaces in series 2, have a minimal level difference of 2.5 metres, spaces can be connected to each other directly. A sequence of interactive high-

234

riser morphologies can be incorporated to both increase connectivity and provide seating in these areas.

Series 3 of the connected spaces receive the highest sunlight, being situated at a high altitude. Three dimensional morphologies may be used to elevate trees in order to provide more shading. Additionally, this morphology also provides privacy to residential units that face the open spaces using plants as buffer.

Design Proposal | Multi-level Ecology

CLUSTER 1 - SERIES 3

Spaces:

Public Park Playground Network: Secondary

CLUSTER 1 - SERIES 2

Spaces:

Services and utilities Restaurants Network: Primary branch

CLUSTER 1 - SERIES 1

Spaces:

Public square Plaza Network: Primary network

Programme Plaza, Public square Utility/ Services, Restaurant Park, Playground Communal seating, Small Park Seating, Private Area

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High

High

Low

Low

Sky view factor

SPATIAL EVALUATION - CLUSTER 2 Quality of open spaces The series 1 of spaces in this cluster comprises of a large park that has a high sky-view factor and a considerably high horizontal view factor along its periphery. Three dimensional level changes can be created onto the space that could act as a viewing gallery overlooking inwards at the playground as well as outwards at the city. The seating may be evenly distributed through areas that have a high as well as low sky-view in order to provide rain shelter.

As communal spaces in series 2 have patches of high sky-view and horizontal view, level differences are created in order to accentuate the patches that have high horizontal view, elevating them to achieve a higher isovist. This elevated space may contain short plants that have sound absorption capabilities.

The private and communal spaces in series 3 are treated in a way similar to cluster 1. As they are situated at high altitudes, level differences may be used in order to elevate trees in order to provide more shading. The morphology also provides privacy to residential units that face the open spaces using plants as buffer.

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Horizontal view factor

Design Proposal | Multi-level Ecology

CLUSTER 2 - SERIES 3

Spaces:

Residential terrace Communal seating Network: Secondary

CLUSTER 2 - SERIES 2

Spaces:

Communal parks Communal seating Network: Primary branch

CLUSTER 2 - SERIES 1

Spaces:

Playground Public parks Network: Primary branch

Programme Park, Playground Communal seating, Small Park Seating, Private Area

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High

High

Low

Low

Sky view factor

SPATIAL EVALUATION - CLUSTER 3 Quality of open spaces The series of spaces at low altitude in cluster 3 comprise of spaces with a high degree of programmatic variation. This raises the need to detail the spaces according to their unique character with smooth transitions.

As a lot of buildings in this cluster are low-rise, its public spaces have a high sky-view factor and receive high incident sunlight. Due to these conditions and the high pedestrian flow, large amounts of seating may be provided in these spaces.

This cluster is situated closest to the harbour.

The horizontal view analysis shows that the communal spaces at high altitude in the cluster have an unobstructed 360 degree view, with a view overlooking the harbour on the northern side. A viewing gallery can be created for the users of this space to allow that to enjoy the view.

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Horizontal view factor

Design Proposal | Multi-level Ecology

CLUSTER 3 - SERIES 3

Spaces:

Residential spill-out Communal seating Network: Secondary

CLUSTER 3 - SERIES 2

Spaces:

Public square, Restaurants, playground Network: Primary network

CLUSTER 3 - SERIES 1

Spaces:

Utility and services, Restaurant, play area Network: Primary branch

Programme Plaza, Public square Utility/ Services, Restaurant Park, Playground Communal seating, Small Park

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DESIGN TRANSLATION Topographical level changes From the horizontal view, sky-view and pedestrian flow analysis conducted, and parameters are extracted that would help improve the spatial conditions.

Visual 1 portrays a seating area created to increase the horizontal view factor of the area such that users from the offices around the space can enjoy the view of the city from this space.

This is done by achieving topographical changes to the surface by creating three dimensional morphologies whose function varies from spaceto-space. This topographical variation can be used to provide seating, elevate trees in order to provide more shading or privacy, create a podium to maximize horizontal view, interactive staircases and programmatic buffers.

Visual 2 shows that the area that has a high sky-view value is left untouched and no topographical variation is incorporated to allow pedestrians to take this route and enjoy the sunlight. This design decision is also taken to avoid introducing permanent seating in areas that do not have rain protection.

The adjacent visuals are captured from the spaces in cluster 1 to explain the topographical variation brought about in the cluster. The topographical variation is created according to design decision taken in order to improve the spatial quality of the cluster.

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Visual 3 exhibits how topographical changes create spaces of interest and gather in a public plaza. The level differences also elevate trees to provide a higher degree of shading from the North summer sun.

Design Proposal | Multi-level Ecology

High sky view factor High horizontal view factor

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DESIGN RESULT Sample cluster 1 The implementation of the surface morphologies to the clusters brings us to the result of the local design.

The spatial programme of the interconnected spaces along with the plantation and the topographical differences create unique spatial characteristics in an otherwise monotonous urban fabric.

The open spaces at high altitudes exhibit a balance of maximizing horizontal and the privacy of the residential units. As this cluster comprises of the least plantation density, the morphological changes supplement the lack of trees to provide privacy to the residents.

Cluster 1 has transformed into an interactive plaza that not only channels the flow to the central market, but is now a destination in itself. It comprises of a series of spaces that can accommodate various activities, creating the opportunity to harbour civic and social discourse.

Spaces at mid-range altitudes have large lawns on which people can meander, halt in the shade. These areas provide an escape from the cityâ&#x20AC;&#x2122;s bustle.

This cluster holds the largest area of open ground space, surrounded by shaded seating. This creates a flexible space that can potentially hold deployable programmes.

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The materiality extracted from the zoning plays an important role in defining the local character of the cluster. Assigning materiality at a local scale gives the space texture, further enriching the urban environment. For instance, the topographical variation is created using a semi-permeable lightweight material such as pumice stone with a low thermal mass. This material would not retain heat, further contributing to the heat island effect. The permeability of this material would also help with the water collection strategy. A wide palette of materials and their properties are explored in the appendix C.

Design Proposal | Multi-level Ecology

Result Data

Planter area Lawn area

46

The number of the species

Pedestrian area Designated programme

Local Area Zoning Zoning type

Area

Area ratio

Planter area

4296 m2

30%

Lawn area

1705

m2

12%

Pedestrian area

2909 m2

20%

m2

38%

Designated programme

5453

Area that level changes

High topographical variation provides seating, shading and privacy to residents.

Design translation result

Elevated seating provides an enhanced horizontal view.

Level changes create unique spatial character, inviting people for social interaction

Minimum height change 400mm

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DESIGN RESULT Sample cluster 2 Cluster 2 exhibits that peripheral areas are given equal importance as central areas. The residents of this cluster are no longer secluded as they now have and easy access to central Sai Ying Pun. The cluster is no longer dependant on the Northern parts of the site to get access to parks and playgrounds. There is a park on the lower levels of the cluster that is large enough to accommodate sports facilities. Seating is provided at the circumference of this park to both look inwards at the park and outwards onto the city.

The spaces at mid-range comprise of lawns and terraces overlooking onto the park. These areas comprise of services and utilities that make the cluster partially self sustainable.

Spaces at higher altitudes in this cluster comprise of the highest plantation density on site. These spaces in the most part are extremely private, except for three view points from where there is a clear view of the harbour or the mountains.

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Design Proposal | Multi-level Ecology

Result Data 44

The number of the species Local Area Zoning Zoning type

Area

Area ratio

Planter area

3220 m2

44%

Lawn area

1593

m2

22%

Pedestrian area

1097 m2

15%

m2

18%

Designated programme

1317

Area that level changes

Elevated trees providing privacy to the open space as well as the residents.

Design translation result

Series of steps provided to overlook the activity in the park

Large park capable of accommodating sports facilities

Minimum height change 400mm

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DESIGN RESULT Sample cluster 3 Cluster 3 comprises of the highest degree of programmatic and institutional variation, as well as the maximum plant diversity of the three clusters.

This creates an opportunity to detail the spaces according to their unique character with smooth transitions.

The low altitude public spaces are areas with complex interrelationships between programmes, institutions, the primary network and the local design. This is one of the most important areas on site as it experiences the highest pedestrian flow. As a result, the space is designed with wide pavements and pockets of spillout areas that dampen the pedestrian flow. A series of small scale services, cafĂŠs and restaurants are situated on the mid-range altitudes that further reduce the pedestrian load.

Morphological level changes are created to provide seating away from the pedestrian area that acts as a space for respite from the city commotion.

The communal open space that interconnects the three residential buildings at high altitude is

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completely shielded from the bustle of the series of spaces below. The Northern edge of the communal space comprises of a viewing gallery which offers an uninterrupted view of the harbour and the bay.

The viewing gallery is well shaded with trees and comprises of ample seating to accommodate a large group of people.

Design Proposal | Multi-level Ecology

Result Data 52

The number of the species Local Area Zoning Zoning type

Area

Area ratio

Planter area

4220 m2

50%

m2

26%

Lawn area

2230

Pedestrian area

877 m2

Designated programme

1183

m2

10% 14%

Area that level changes

Viewing gallery overlooking the harbour and the bay

Design translation result

Local activity allocated to multi-level open space to reduce primary pedestrian load

Minimum height change 400mm

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VISUALIZATION OF SPACES

248

Design Proposal | Multi-level Ecology

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Through the research and design exploration, this project is a vision of how serviced public spaces connected at multiple levels enrich high-rise highdensity urban environments.

With the result of the study, the urban fabric has transitioned from isolated point blocks that can only be associated with each other via ground level connections of a monotonous urban fabric, to an integrated, threedimensional, ecological urban patch composed of interconnected open spaces which have the potential to support diversified activities and retain civic integrity.

There is a significant shift in the movement pattern that was linear, mono-functional and purpose specific to a mobility pattern that is now experience driven. Multilevel Ecology encourages people to meander through open green corridors that offer an array of activities.

Although this research model is tested in the context of Hong Kong, it is imperative to acknowledge that this research can be equally viable in similar urban environments with varying parameters.

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Design Proposal | Multi-level Ecology

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7 CONCLUSION

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CONCLUSION Achievements The multi-scalar approach in this project has resulted in an interconnected and interrelated system that enhances the sociocivic conditions of Sai Ying Pun. It is important to break down the concluding observations and achievements of the individual local clusters and that of the larger urban area. Clusters individually achieve sequences of multilevel connected public spaces that promote social interaction.

The changed pedestrian movement patterns create the possibility to meander and halt at desired places; this overlap creates opportunities to share spaces and resources.

At the global scale, there is an evident overlap of institutions throughout the urban area, i.e., residential, commercial, office and leisure- now have the opportunity to interact, opening the possibility for a new dialogue.

Though more than 70% of Hong Kongâ&#x20AC;&#x2122;s land is protected ecosystems, the dense urban centres of the city have negligible biodiversity. Having introduced more than 19,000 m² of vegetated land, this proposal has significantly enhanced local biodiversity.

Although this research model is tested in the context of Hong Kong, it is imperative to acknowledge that this research can be equally viable in similar high-rise urban environments with varied parameters. The research establishes the importance of multi-level ecologies and sets a spatial framework for future developments to ensure social and mental well-being while accommodating greater densities in isolated high-rise infrastructure.

System Refinements The design research at the moment lacks materiality. There may be better solutions than using concrete to develop spaces in such an urban environment. Alternate materials may perform better environmentally and leave a smaller ecological footprint.

Materials with high porosity may be fitting for the hot and humid climate.

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An in-depth evaluation of the existing structure of individual buildings may have increased the limitations of the open space distribution. Techniques to increase the structural strength of proposed spaces could be explored to achieve larger spans or greater vegetation loads.

Future developments At the global scale, a time-line can be introduced. The time-line will divide the process into stages. Strategies can be incorporated to make the transition smooth. This time-line will also take into consideration the growth period of vegetation.

Large areas on the open spaces created receive high solar radiation which may limit activity. A shading system may be proposed that provides shelter from both the rain and the seasonal sun.

The hydrological system can be further explored. Morphological changes can be made to the design that aid in maximizing water collection.

The research may be put to the test by incorporating it in a similar urban environment with varying parameters.

Conclusion | Multi-level Ecology

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8 BIBLIOGRAPHY

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Bibliography Domain “Atlas of Urban Expansion.” Atlas of Urban Expansion - Hong Kong, Hong Kong. Accessed August 27, 2019. http://www. atlasofurbanexpansion.org/cities/view/Hong_Kong_Hong_Kong.

Berg, Nate, and Nate Berg. “Hong Kong, the City Without Ground.”

CityLab, August 20, 2012. https://www.citylab.com/design/2012/08/ hong-kong-city-without-ground/3000/.

Bolchover, Joshua, and Peter Hasdell. Border Ecologies: Hong Kongs Mainland Frontier. Basel: Birkhäuser, 2017.

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Fig.2. (top) Density of Hong Kong, Mexico City and London.................23 urbanage.lsecities.net. Accessed September 10, 2019, from https://urbanage.lsecities.net/ search?content_type=[“data”]&theme=[17]&year=[“2015”].

Fig.3. High density city and its preserved area, Hong Kong.................24 Mishev, Dina. “Hong Kong’s Urban Jungle Is Real, Not a Metaphor for Concrete and Steel.” The Washington Post. WP Company, July 7, 2016, from https://www.washingtonpost.com/lifestyle/travel/ hong-kongs-urban-jungle-is-real-not-a-metaphor-for-concrete-and-steel/2016/07/07/bc6951d83c77-11e6-80bc-d06711fd2125_story.html.

Fig.4. (left) A residential precinct in Sha Tin, New Territories, Hong Kong, built in 1970s..................26 City One Shatin (Phase 3C) - BEAM Plus Online Exhibition. Accessed September 10, 2019, from http:// greenbuilding.hkgbc.org.hk/projects/view/109.

Fig.5. (bottom) An example of a pencil tower, Hong Kong, built in 2010s..................26 “3262: Executive Homes.” , Wan Chai Apartment For Rent. Accessed September 15, 2019, from https://www.executivehomeshk.com/properties/wan-chai/5-star-street/3262.

Fig.6. A pocket park below the highway, Hong Kong.................28 “Reimagining Hong Kong’s Pocket Parks.” thinking city //, April 5, 2019, from https://thinkingcity.org/ portfolio/reimagining-hong-kongs-pocket-parks/.

Fig.7. Open space on the platform level within a public estate, Hong Kong.................29 cyclub.happyhongkong.com. Accessed September 10, 2019, from http://cyclub.happyhongkong.com/ viewthread.php?tid=143136&authorid=&attach=.

Fig.8. Sit-out area with greenery in a high density area, Hong Kong.................31 “Will a Lack of Open Space Damage Generations of Hongkongers?” South China Morning Post, July 20, 2018, from https://www.scmp.com/news/hong-kong/community/article/2118314/will-lack-openspace-damage-generations-hongkongers.

Fig.9. Empty reservoirs in Hong Kong.................34 “Water Shortages-Empty Reservoirs Means Water Rationing.” Gwulo. Accessed September 2, 2019, from https://gwulo.com/atom/30354.

Fig.10. (next page top left) Exterior of The pinnacle @ Duxton in Dawson, Singapore.................38 LaBarre, Suzanne. “World’s Best Skyscraper Awards Include Stout, Rusty School Building in England.” Fast Company. Fast Company, July 30, 2019, from https://www.fastcompany.com/1661720/ worlds-best-skyscraper-awards-include-stout-rusty-school-building-england.

Fig.11. (next page bottom left) Sky garden of The pinnacle @ Duxton in Dawson, Singapore.................38 “Pinnacle@Duxton.” Visit Singapore Official Site. Accessed September 2, 2019, from https://www. visitsingapore.com/see-do-singapore/architecture/modern/pinnacle-at-duxton/.

Fig.12. (next page top right) Exterior of SkyVille in Dawson, Singapore.................38 “SkyVille @ Dawson.” The Skyscraper Center. Accessed September 6, 2019, from http://www. skyscrapercenter.com/building/skyville-dawson/14117.

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Fig.13. (next page bottom right) Sky garden of SkyVille in Dawson, Singapore.................38 20 September, 2017 By Paul Finch. “Editorial: Revolutions Mean Mass Housing – and Should Mean Good Design.” Architectural Review. Accessed September 3, 2019, from https://www.architecturalreview.com/essays/letters-from-the-editor/editorial-revolutions-mean-mass-housing-and-shouldmean-good-design/10023545.article.

Fig.14. (prev. page top) Access diagram of The Pinnacle @Duxton.................41 Menz, Sacha. Public Space Evolution in High-Density Living in Singapore: Ground and Elevated Public Spaces in Public Housing Precincts. Zürich: ETH-Zürich, 2014.

Fig.15. (top) Section through The Pinnacle @Duxton showing green spaces at various levels.................41 “ARC Studio Architecture Urbanism · Pinnacle @ Duxton.” Divisare. Accessed September 2, 2019, from https://divisare.com/projects/150328-arc-studio-architecture-urbanism-pinnacle-duxton.

Fig.16. (bottom) Section through SkyVille showing green spaces at various levels.................41 Rojas, Cristobal. “SkyVille / WOHA.” ArchDaily. ArchDaily, December 8, 2016, from https://www. archdaily.com/800832/skyville-woha.

Fig.17. (top) Elevation of the Central Mid-level escalator and walkway system.................42 Han, Wang. “Hong Kong / Government Intervention (1980s) Central–Mid-Levels Escalator and Walkway System.” ASIAN CITIES RESEARCH, December 18, 2016, from http://fac.arch.hku.hk/asiancities-research/hong-kong-government-intervention1980s-central-mid-levels-escalator-andwalkway-system/.

Fig.18. [right] Location of Central Mid-level escalator and walkway system......................40 Han, Wang. “Hong Kong / Government Intervention (1980s) Central–Mid-Levels Escalator and Walkway System.” ASIAN CITIES RESEARCH, December 18, 2016, from http://fac.arch.hku.hk/asiancities-research/hong-kong-government-intervention1980s-central-mid-levels-escalator-andwalkway-system/.

Fig.19. (top) Elevated walkways and underground tunnels of Central.................43 “Pin on History of Me.” Pinterest. Accessed September 10, 2019, from https://www.pinterest.jp/pin/25 5649716325156802/?lp=true.

Fig.20. (middle)Elevated walkways being utilized as social meeting spaces.................43 “Eni’s Story: Why Bethune House Offers an Essential Lifeline for Domestic Workers Facing Abuse.”

Hong Kong Free Press HKFP, July 23, 2018, from https://www.hongkongfp.com/2018/07/23/enisstory-bethune-house-offers-essential-lifeline-domestic-workers-facing-abuse/.

Fig.21. (bottom) Complex circulation under and over ground in Central.................43 “Cities Without Ground A Hong Kong Guidebook.” Cities Without Ground / Maps. Accessed September 1, 2019, from http://citieswithoutground.com/maps/.

Fig.22. (top) View of t he socially active park - High Line, New York.................44 Thrillist, October 23, 2018 https://www.thrillist.com/lifestyle/new-york/things-to-do-near-the-highline-nyc

Fig.23. (1 from top) Viewing gallery at the Eastern end of High Line.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.24. (2) View of the narrow walkway at High Line.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

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Fig.25. (3) View of the Mile-long orchestra, late night performances at the city that never sleeps.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.26. (4) Wooden benches scattered at the High Line.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.27. (5) People spilling out onto the lawns at High Line.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.28. (6) Amphitheatre at High Line during lunchtime..................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.29. (7) Stepped seating along existing facades at High Line.................45 The highline official, January 3, 2019, https://www.thehighline.org/visit/

Fig.30. Location of Sai Ying Pun in Hong Kong.................62 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.31. Aerial view of Sai Ying Pun, Hong Kong.................63 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.32. (next page left)Secondary Street (First Street).................66 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.33. (next page middle)Central Street (Third Street).................66 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.34. (next page bottom)Central Street (Queens Street).................66 “Category:2016 in Centre Street, Hong Kong.” Category:2016 in Centre Street, Hong Kong - Wikimedia Commons. Accessed September 2, 2019, from https://commons.wikimedia.org/wiki/Category:2016_ in_Centre_Street,_Hong_Kong.

Fig.34. (next page bottom)Central Street (Queens Street).................6671 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.36. Urban open space created from residue gap remaining from the redevelopment of the adjacent building..................71 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.37. Street view of a pocket park.................................................................................<?> “第三街遊樂場 .” Wikipedia. Wikimedia Foundation, May 4, 2019, from https://zh-yue.wikipedia.org/ wiki/ 第三街遊樂場

Fig.38. Street view of a side walk......................................................................................74 Google Maps. Google. Accessed September 1, 2019, from https://www.google.com/maps.

Fig.39. Street view of a side walk......................................................................................<?> “ 亜美的時間 2 Amey’sTime2.” 2011 年 2 月 23 日香港・マカオ行 追記・完成版 - 亜美的時 間 2 Amey’sTime2. Accessed September 2, 2019, from https://blog.goo.ne.jp/anemone339/e/ d9ef6b27228bf2530df11ccad1a4afbb.

Fig.40. Street view of an alley...........................................................................................<?> summerkid_summergirl. “[Hong Kong 6D5N] Stone Slabs Street 石板街 @ Pottinger Street, Central, Hong Kong.” Malaysian Flavours, November 13, 2016, from http://www.malaysianflavours. com/2014/07/hong-kong-6d5n-stone-slab-pottinger-street-central-hong-kong.html.

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Fig.41. Street view of a POSPD................................................................................<?> “ アイランドクレスト (Island Crest ).” アイランドクレスト｜賃貸住宅アパート｜スターツ香港 . Accessed September 1, 2019, from https://kaigai.starts.co.jp/hongkong/detail/4363.

Fig.42. (1 from top) Plaza, Public square.. .............. .183 The cities designing playgrounds for the elderly, January 2, 2019, https://www.bbc.com/ worklife/article/20191028-the-cities-designing-playgrounds-for-the-elderly

Fig.43. (2) Utility/ services, Restaurant.. .............. .183 Hong Kong Wah Kee Restaurant Okubo, January 2, 2019, https://japanrestaurant.net/en/shop/ hong-kong-wah-kee-restaurant/

Fig.44. (3)Park, Playground. .............. ..183 Demonstrate and share learning, January 2, 2019, ttps://web.seesaw.me/

Fig.45.(4) Communal seating, small park.. .............. .183 Pocket Parks of NYC, December 22, 2018, http://www.pocketparksnyc.com/

Fig.46. (5)Seating, private area.. .............. .183 HONG KONG DESIGNERS REIMAGINE THE CITY’S POCKET PARKS, January 2, 2019, https:// thinkingcity.org/2019/03/29/hong-kong-designers-reimagine-the-citys-pocket-parks/

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9 Appendix

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APPENDIX A: PLANTING DISTRIBUTION SCRIPT VB script for circle packing in multiple curves The input for the plantation experiment is the complete list of trees along with their specifications of their canopy radius, height and soil depth.

With the grid curves of varying sized as the bounding cell, the GA calculates correlates the spatial load limitation and correlates it with the complete set of input trees.

An additional evaluation factor is programmed that maximizes the variation in the types of trees used, representing biodiversity.

268

Appendix | Multi-level Ecology

Option Strict Off Option Explicit On Imports System Imports System.Collections Imports System.Collections.Generic Imports Rhino Imports Rhino.Geometry Imports Grasshopper Imports Grasshopper.Kernel Imports Grasshopper.Kernel.Data Imports Grasshopper.Kernel.Types Imports System.IO Imports System.Linq Imports System.Data Imports System.Drawing Imports System.Reflection Imports System.Windows.Forms Imports System.Xml Imports System.Xml.Linq Imports Microsoft.VisualBasic Imports System.Runtime.InteropServices Imports Rhino.DocObjects Imports Rhino.Collections Imports GH_IO Imports GH_IO.Serialization

If (C Is Nothing) Then Return If (N <= 0) Then Return If (Not C.IsClosed()) Then Print(“Your input curve is not closed.”)

Return End If

Dim radius As Double = R(i) Dim point As New Point3d(U.ParameterAt(rnd.NextDouble()), V.ParameterAt(rnd.NextDouble()), 0) If (C.Contains(point, Plane.WorldXY) <> Rhino.Geometry.

PointContainment.Inside) Then Continue Do Dim ct As Double C.ClosestPoint(point, ct) Dim cp As Point3d = C.PointAt(ct) If (point.DistanceTo(cp) < radius + distfront) Then Continue Do For Each insideC As Curve In InC If (insideC.Contains(point, Plane.WorldXY) <> Rhino.Geometry.

PointContainment.Outside) Then Continue Do insideC.ClosestPoint(point, ct) cp = insideC.PointAt(ct) If (point.DistanceTo(cp) < radius + distfront) Then Continue Do Next

For Each crc As Circle In circles If (point.DistanceTo(crc.Center) <= (crc.Radius + radius + interdist)) Then Continue Do Next Dim circle As New Circle(point, radius) circles.add(circle) index.add(i) If (circles.Count >= N) Then Exit Do attempts = 0 Loop A = circles B = index

Dim bbox As BoundingBox = C.GetBoundingBox(False) Dim U As New Interval(bbox.Min.X, bbox.Max.X) Dim V As New Interval(bbox.Min.Y, bbox.Max.Y) Dim rnd As New Random(rand) Dim index As New List(Of Double) Dim circles As New List(Of Circle) For Each cir As Circle In PreCircles circles.Add(cir) Next Dim attempts As Int32 = 0 Do While (attempts < maxtries) attempts += 1 Dim i As Double = int(rnd.Next(R.Count))

r4

r3 r1

r6

r2 r7

r5

r: Tree spread radius

269

APPENDIX B: PLANTING STUDY Species of evergreen plants are catalogued and are used as inputs for the planting experiment. Each species is categorized as per water requirement, tree height, canopy spread, soil depth and wind resistance.

This data is correlated with the spatial requirement and limitations in the planting experiment.

270

Appendix | Multi-level Ecology

Planting data

Bauhinia x blakeana Ir2 | H1 | C1 | S1 | W1

Michelia chapensis Ir2 | H2 | C2 | S1 | W2

Ficus benjamina Ir1 | H1 | C1 | S1 | W2

Elaeocarpus hainanensis Ir2 | H2 | C2 | S1 | W1

Lagerstroemia Ir3 | H2 | C3 | S2 | W2

Chukrasia tabularis Ir3 | H3 | C3 | S2 | W1

Livistona chinensis Ir1 | H2 | C1 | S2 | W2

Senna surattensis Ir2 | H1 | C1 | S1 | W1

Syzygium jambos Ir2 | H1 | C1 | S1 | W2

Ficus â&#x20AC;&#x2DC;Variegataâ&#x20AC;&#x2122; Ir3 | H3 | C2 | S2 | W2

Garcinia subelliptica Ir2 | H2 | C2 | S2 | W2

Osmanthus fragrans Ir2 | H1 | C1 | S1 | W2

Sphaeropteris lepifera Ir2 | H1 | C1 | S1 | W2

Phoenix roebelenii Ir1 | H1 | C1 | S1 | W2

Magnolia grandiflora Ir2 | H1 | C2 | S3 | W2

Melaleuca bracteata Ir2 | H2 | C1 | S1 | W2

Hibiscus tiliaceus Cinnamomum burmannii Ir2 | H2 | C1 | S2 | W2 Ir2 | H1 | C1 | S1 | W2

Plumeria rubra Ir2 | H1 | C1 | S1 | W2

Cycas revoluta Ir1 | H1 | C1 | S1 | W2

Juniperus chinensis Ir1 | H1 | C1 | S1 | W2

Low

Medium

High

Ir1 0.1-0.3

Ir2 0.4-0.8

Ir3 0.9-1.2

Tree Height (m)

H1 4-12

H2 13-20

H3 20-30

Canopy Spread diameter (m)

C1 4-8

C2 9-12

C3 13-18

S1 0.2-0.5

S2 0.6-1.0

S3 1.1-1.5

W1 Low

W2 High

Water Requirement (m3)

Soil Mass (m) Wind Resistance

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APPENDIX C: MATERIAL STUDY It is common knowledge that the material palette of Hong Kongâ&#x20AC;&#x2122;s urban fabric is concrete and steel heavy. These materials have a high thermal mass and substantially contribute to the heat island effect.

Additionally, these materials have a high runoff coefficient and are unable to slow down storm water, consequently resulting in flash floods. A new material palette needs to be introduced that gives the urban space tactile texture, enhances the functional systems associated with the space such as drainage or structural and performs well environmentally.

In this design research, surface materials should largely have a low thermal mass, have high porosity, be lightweight and have high emissivity. Such a material would not retain heat, would permeate water through to the collection system, absorb moisture, be installed at high altitude and reflect radiation. Similar materials can be utilized for surface cladding and soft paving.

As the vegetation is a key aspect of the project, it is important to carry out a soil study to understand its, load, porosity and runoff coefficient. Planting

272

at high altitudes, the major load contributors are primarily the soil and water load. The soil load can be minimized by selecting a composite top-soil that is lightweight and is capable of retaining water.

Structural replacements for concrete and steel can be considered, however the focus of the design research lies in the spatial character and socio-civic value. This aspect of the research can be developed in the future.

Appendix | Multi-level Ecology

Weight and runoff coefficient of materials

Galvanised steel W: 7850 kg C: 0.95

Stone pavers

Weight/m3

W: 2750 kg C: 0.75

Concrete pavers

Prefabricated concrete

W: 2400 kg C: 0.90

W: 2400 kg C: 0.95

Asphalt - concrete W: 2243 kg C: 0.92

Sandy soil W: 1900 kg C: 0.32 Loam soil W: 1600 kg C: 0.20

Pea gravel W: 1522 kg C: 0.45 Spaced wooden pavers

Fly-ash blocks W: 700 kg C: 0.78

W: 700 kg C: 0.55 Pumice stone gravel Bamboo cladding W: 641 kg Topsoil-woodchip C: 0.26 W: 500 kg composite C: 0.42 W: 450 kg Woodchip C: 0.18 W: 380 kg C: 0.15

0

WPC Decking W: 250 kg C: 0.58

Existing Proposed Cork cladding W: 240 kg C: 0.65

Runoff Coefficient (c)

1.00

Plantation Layers

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