Project Shea - The Green Cradle (Report)

THE GREEN CRADLE PROJECT Kan Sze Nok Sharon Kwong Yuk Chun Amy Kwong Yuk Shan Anna Yeung Sin Yee Tiffany

Table of Contents Abstract

p. 2

Professional Team

p. 3

I.

Project Background

p. 4-6

II.

Vision & Design Principles

p. 7

III.

Overall Design

p. 8-11

IV.

Renewable Energy Generation

p. 12-15

V.

Internal Circulation and Natural Ventilation

p. 15-16

VI.

Smart Water Use

p. 17-21

VII.

Green Living Wall and Community Garden

p. 22-27

VIII.

Stackable and Recyclable Building Materials

p. 27-28

IX.

Sustainable and Co-living Style

p. 29

X.

Conclusion

p. 30

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Abstract This report is submitted for Project Shea for a design competition of a robust prototype for future sustainable dwellings and communities at a reference site in Jurong Eco Garden, Jurong, Singapore. Background study of the project nature and Subject Site provides the foundation of formulating the vision, design principles and implementation mechanism of the design proposal.

With due considerations international call for adopting green living and community design for strengthening relationships among members of the communities, design proposal "The Green Cradle" was formulated with the aim to foster human-nature symbiosis, community bonding and identity building, as well as sustainability in the way of living of people in future.

"The Green Cradle" consists of 3 houses consisting connected circular spaces with the aim to create an organic form of dwelling delivering residents a nature-like experience. The 3 designs provide differing space allocations and interior designs to encourage a mix of households to live with the nature, interact with their neighbors and contribute to promote sustainable lifestyle. Apart from comprehensive hardware that generates renewable energy, makes efficient use of household waste and water resources, and allow eco-friendly farming and landscaping features that enhance the living environment, software including the provision of semi-public-open-space for holding various social and community activities can also promote healthy living with strengthened community bonding and identity.

It is envisioned that "The Green Cradle" will be the incubator for sustainable urban living with the adoption of advanced green technology, innovative dwelling design that fosters human-nature interactions, and community planning and design model that bring members of the community together.

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Professional Team Kan Sze Nok, Sharon Master of Science in Urban Planning, The University of Hong Kong Sharon finished her first degree in UK studying Applied Environmental Science and Geography, and currently doing the Master of Science in Urban Planning in The University of Hong Kong.

She was working in both public and private sectors in relation to sustainable urban development.

She has sincere interest in urban resilience and environmental sustainability, as well as enhancing urban climate resilience through sensitive design and green innovative technology.

Kwong Yuk Chun, Amy Master of Science in Urban Planning, The University of Hong Kong Amy completed her first degree at The University of Melbourne studying the Bachelor of Environment with a major in urban planning and design. She is now studying the Master of Science in Urban Planning at The University of Hong Kong. She was working in the public sector in relation to territorial planning in Hong Kong. Her experience in Melbourne has instilled in her the idea of place-making and sustainable community together and connect the urban space to the people who use the area.

Kwong Yuk Shan, Anna Bachelor of Architectural Design, Monash University Anna is currently doing her first degree at Monash University in Melbourne, Australia. Her passion for building design has gathered the lens of green and sustainable architecture, as well as recyclable building materials and energy consumption. She has put forward an inclusive building mechanism from energy consumption to energy generation.

Yeung Sin Yee, Tiffany Master of Science in Urban Planning, The University of Hong Kong Tiffany had her first degree of Bachelor of Arts in Urban Studies in The University of Hong Kong and continues with the Master of Science in Urban Planning at her alma mater. She has been working in private and public sectors in the housing and town planning fields. Her knowledge has contributed a comprehensive analysis of the local character and policies following the concept of green and sustainable urban development. She has a strong desire to rebuild the human-nature relationship, with an emphasis on the introduction of native and arable species in Singapore.

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I.

Project Background Tackling climate change has been evolving as a worldwide issue in the past decades. By 2050, more than 68% of the world’s population will be living in cities / urban areas. With human activities as the prime cause of the deteriorating environmental quality and climate change, the search for a new way of living featuring eco-friendly and self-sustainable lifestyle with reduced consumption and burden to the natural environment has been readily investigated by eco-business enterprises and researchers. The Shea Project presents an opportunity for designing a robust prototype of future sustainable living model for people in urban areas.

Site location The Subject Site - Jurong Eco Garden is located at the west of Jurong, a residential town in western Singapore. The Jurong Eco Garden is the first garden located within an industrial park - ClearTech Park of Singapore, where eco-business solutions are derived from the eco-industrial park.

Previously a secondary forest, the Jurong Eco Garden is the habitat providing 5ha of lush greenery and a variety of natural species, including migrating birds and butterflies. With a total of 4 zones with freshwater swamps, walking trails and natural streams, the Garden has become an attractive exploring ground for families, teenagers, elderly and bird watchers to get in touch with the nature.

Within the Jurong Eco Garden, a piece of land of 300 sq.m. is reserved for the testbed of Project Shea, to explore the potential for green and sustainable living and consumption solutions for future homes of people. Capitalizing on the close proximity of the site to the Nanyang Technological University, ClearTech Park - the first eco-business park for R&D and innovation testbed for green technology solutions, as well as the residential area in Jurong West, the site provides excellent potential as the testing ground for a new way of living in both the environmental and social aspects.

In terms of environment, innovative housing design and materials can render climate-resilient and carbon negativity living experiences to residents. In the social aspect, new forms of housing design and space allocation can provide enhanced opportunities for community interactions and engagements among different households of various sizes, background and lifestyles.

Climate and weather characteristics Jurong enjoys a tropical climate with uniform and high temperature, and abundant rainfall throughout the year. The temperature ranges at 31-33 °C during daytime and 23-25°C during night time. The area has a high annual humidity rate of 83.9%, with the range of 60-90%. With an average annual rainfall of 2165.9 mm, nearly half of the days across a year (around 167 days) in the area experiences heavy rainfall with thunder. Due considerations on the design of the houses and living space, particularly in terms of building materials, ventilation and shape, are needed to ensure a safe and comfortable living environment to be provided. At the same time, opportunities derived from the climate characteristics of the site can be capitalized through innovative climate and weather-adaptive design, with the aim to embrace and make the best use of what nature provides to us.

Figure 1.1 and 1.2 below show the distribution of temperature and rainfall volume from November 2019 to September 2019 respectively.

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Figure 1.1 Average Temperature from November 2018 to September 2019 in Jurong West (Source: World Weather Online, 2019)

Figure 1.2 Average Rainfall Amount (mm) and Rainy Days from November 2018 to September 2019 in Jurong West (Source: World Weather Online, 2019)

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Average wind speed and orientation of prevailing wind From December to early March, the prevailing wind in Singapore blows at the north to northeast direction. The periods between late March and May, as well as October and November refer to the inter-monsoon period when severe thunderstorms and hot afternoon become more frequent.

Monsoon going southeasterly to southerly starts from June to September. Occasional “Sumatra Squalls” with wind gusts of 40-80 km/h between predawn hours and mid-days are frequent, with short durations of showers and thunderstorms in the afternoon.

During days without extreme weather, the mean surface wind speed of Singapore is around 2.5 m/s. The direct solar irradiance is 120 Watts/m2 (Meteorological Service Singapore, n.d.).

It is observed that wind and rainfall are frequent of nearly half a year in Singapore. These natural resources have the opportunity to become sources of renewable energy providing for the living of residents in the site, through relevant design considerations and infrastructure provision.

Target temperature, energy and water to be generated As outlined in the Design Brief, the requirements of the dwelling design in the technical environmental aspect include temperature, water and energy.

For the shelter structure design, the shelter should be made of eco-friendly and affordable materials that are easy to assemble, as well as be able to maintain indoor temperature within the range of 24-28°C. The dwelling community should also be able to supply at least 70 litres of water per person per day. Systems of water recycling, rainfall water catchment and treatment should also be provided to reduce water waste and achieve more effective utilization of existing and used water resources.

Last, for energy generation, energy is encouraged to be generated from renewable resources or through waste-to-energy. A maximum of 3kWh per person per day for domestic use is required, as well as an energy store system with the capacity allowing 2 days energy storage as backup.

Summary of Site and Project Background To wrap up, the locational features, climate and weather, and community characteristics of the Subject Site together provide the framework of requirements and opportunities to be fulfilled and captured respectively in the design of the Project. The vision and design principles of this project are built upon the above analysis, and will be introduced in Chapter 2 below.

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II.

Vision & Design Principles Vision - “The Green Cradle” “The Green Cradle” is intended to reimagine sustainable shelters to the next level. Bringing together cutting-edge hybrid renewable energy technologies, rainwater harvesting, greywater and waste recycling systems, as well as human scale design; “The Green Cradle” delivers oneof-a-kind sustainable community and lifestyle to its inhabitants.

Design Principles

Figure 2.1 The 3 elements of design principles (Source: Design Team) As shown in Figure 2.1 above, 3 elements - (1) Human-Nature Symbiosis, (2) Community Bonding, and (3) Sustainability, will form the basis that guides the design of “The Green Cradle”. The design principles corresponding to each element are listed as follows.

Human-Nature Symbiosis • Promote eco-friendly living and consumption pattern through encouraging extensive landscaping, “farm your own food” and interactions between residents and nature.

Community Building • Design to foster interactions and identity-building among residents through flexible and innovative activity space design.

Sustainability • Adopt green and sustainable building design and utilities to achieve carbon negativity and self-sustainability of the community.

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III.

Overall Design Design of the Houses Regarding the nature of sustainability, the design aims to create a natural-like feeling with organic shape for the future dwellings and thereby circle is used as the key design element. To fulfill the needs of individuals, there are different sizes of circles which represent different communal spaces for daily necessity including the washroom, bedroom, and dining area. With an aim to encourage community engagement, several semi-public areas are designed for different activities.

Meanwhile, to further strengthen the human-nature relationship, biophilic design is considered which can be reflected on the installation of the external green walls. By installing the green wall, we aim to connect the human with their 5 senses, including sense of sight, smell, sound, taste, and touch. It is because the walls can provide aesthetic landscaping and food sources, as well as nurture lives such as bees and butterflies during the blossoming season. As to enhance the thermal comfort and natural lighting, the design of the roof and high ceiling, together with the windows which are facing the northeast and southwest, allow natural ventilation and capture sunlight.

Figure 3.1 Master Layout Plan for 3 dwelling designs (Source: Design Team)

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Target Groups The proposed 3 types of houses will be suitable for accommodating households of different sizes and compositions, including standard family size of 3 or 4 people, couples, as well as co-living of 4-5 single persons. The target groups were derived from the urban development pattern in the vicinity to the Subject Site. For instance, House for co-living of single persons can accommodate college students from the nearby Nanyang Technological University, who would like to experience a brand new way of green and sustainable lifestyle. Employees and their families of the nearby eco-business park can live in houses designed with standard family size or for couples, so the employee can take advantage of the proximity of his/her home to the workplace, and his/her family members can also benefit from the proximity to the tranquil natural environment of the Jurong Eco Garden.

Functions of 1/F and 2/F A special space allocation and design feature of the 3 houses is that there’s a distinction in the uses of the ground floor and first floor. For the 3 houses, the first floors above ground are designed for residence. For the ground floors, they are proposed to be semi-public open space for accommodating various community activities shared among households living in the 3 houses.

Table 3.1 below summarizes the space allocation, functions and other facilities of the proposed houses. Figure 3.2 below shows the modular design concept while Figure 3.3 indicates the floor plans for the proposed houses.

Table 3.1 Space allocation, functions and other facilities of the proposed houses #1 House

#2 House

#3 House

1/F (residence)

For standard family size of 4 people

For 4-5 single people (one big communal area of kitchen, toilet and bath)

For 2 couples or family size of 3 people (two kitchen and dining areas separated by a wall in one big circle)

G/F (semi-public open space for community activities)

Eating place/ cafe/ cookery studio

Communal / workshop area (i.e. co-working space in daytime and event space during evening)

Mild exercise area (e.g. yoga/scratching) and nursery

Common area outside the houses

-

Table and chairs Community garden Vigorous event/exercise

Green Living Wall

-

Vertical greening of plants and flowers for visual enhancement and cooling.

Hydroponic planter system for crop harvesting.

-

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Roof

-

Hybrid renewable energy generating roof with CO fixation technology.

Infrastructure

-

Integrated waste management and waste-to-energy system Rainwater collection and water recycling facility.

2

Figure 3.2 Modular design concepts (Source: Design Team)

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Figure 3.3 Floor plans of the proposed 3 houses (Source: Design Team)

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IV.

Renewable Energy Generation Hybrid renewable energy generating eco-roof Overview As one of the main features of the Green Cradle, the hybrid renewable energy generating eco-roof (the Hybrid Eco-roof) combines multiple renewable energy sources to fully utilize the abundant solar radiation and moderate wind velocity in the reference site, as shown in Figure 4.1.

Figure 4.1 The renewable energy mechanism of the Green Cradle (Source: Design Team) The Hybrid Eco-roof comprises two energy systems, one being the “Energy Generation System” and the other “Energy Reduction and Recovery System”. Consists of the wind turbine, movable and non-movable solar panel, the “Energy Generation System” is where solar and wind energies will be harvested for the household. On the other hand, The “Energy Reduction and Recovery System” is comprised of daylight and rainwater harvesting system to reduce the potential energy consumption through transparent rooftop and reclaiming rainwater for cooling and household consumption purpose.

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Wind turbine The detailed arrangements of the different compartments are also shown in Figure 4.1. The vertical wind turbine stems at an orientation of the rotating axis perpendicular to the roof and facing the direction of the prevailing wind. The wind turbine is connected to the generators for electricity generation. The energy generated by the wind turbines will be stored in batteries for consumption within the households. The curve-shaped design of the wind turbine creates a venturi effect to increase the wind speed flowing through the turbine and in other words enhancing the energy generation efficiency. Being 1m tall, the wind turbines have a power output of 400W and thus be able to generate about 5,256 kWh annually, given the estimated operating time be 12 hours a day.

Solar panel and daylight harvesting The transparent solar panels are mounted on the roof to collect daylight for electricity generation.

The roof itself is also made of transparent glass in order to ensure sufficient sunlight penetrating into the house to allow more daylight saving during daytime. The solar panel covers a total roof area of 270 m2 and hence able to generate about 43,088 kWh annually, given one square meter of solar panel is able to produce approximately 200kWh of energy annually. Similar to the wind energy, the electricity generated by the solar panels will be stored in batteries for subsequent use in the shelters.

Raindrop energy harvesting According to the latest study of Viola (2018), in tropical countries such as Singapore, Malaysia, Indonesia and Brazil, etc. where the annual rainfall exceeds 2,000 per year, have a great potential in employing raindrop energy harvesting. The principle behind is to harvest the kinetic energy of the ambient vibration of rainwater droplets, which is otherwise wasted in the environment, that fall onto a surface. The vibration and kinetic energy from the falling raindrops will be converted into electricity on the piezoelectric plates.

As shown in Figure 4.2, the piezoelectric structures (the orange rectangles), made of a material that generates dipole moment and also a function of the stress acting on the structure, are bound at both ends of the plate. These piezoelectric plates are mounted onto the solar panel on the rooftop to maximise the amount of raindrop induced kinetic energy and oscillations collected.

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Figure 4.2. The piezoelectric structures on top of the solar panel for raindrop energy harvesting (Source: modified from Viola, 2018)

Considering an average daily precipitation of 5.8 mm/m2 in Singapore, with a kinetic energy at an estimation of 3.27 mJ for one rainwater droplets with an average diameter of 5mm, about one twelfth of the average solar energy can be generated (Viola, 2018).

CO2 fixation technology Apart from powering the household, the Hybrid Eco-roof also powers a CO2 fixation technology device that directly captures and converts CO2 in the ambient air into methanol – an alternative fuel stored in fuel cell for community energy supply and for backup power storage (Bravo and Debecker, 2019).

The CO2 fixation technology mainly comprised of two major process - CO2 absorption and methantion. As shown in Figure 4.1, the compartments for CO2 carbon fixation technology are mainly situated at the bottom of the residence. Powered by renewable energy generated from the Hybrid Eco-roof, the CO2 in the ambient air is first being captured from absorption into the carbon fixation tank. It is then being fed into a reactor and the CO2 is absorbed over the absorbent until saturation by coined “dual functional materials” (DFM), which is able to carry out both the absorption and the hydrogenation of CO2 as shown in Figure 4.3. CO2-free gas and methane (CH4) will be released afterwards. These steps are repeated cyclically.

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Figure 4.3 The procedures of CO2 absorption and methanation (Source: Design Team).

The energy produced will be stored as fuel as backup energy. It is estimated that about 5.4 Liter of liquified methane can be produced in the community, which is equivalent to 9,041 kWh worth of energy being produced in a year.

V.

Internal Circulation and Natural Ventilation To balance indoor comfortability and energy consumption, the Green Cradle has largely adopted natural ventilation within the shelters. The use of large windows and sunroofs will create a strong convection current on the first floor that drives away hot air and trap cold air to cool down the indoor temperature especially during the hot summers in Singapore. Whereas an opening is created on the ground floor, allowing cold air to penetrate and enter the ground floor compartment of the shelter, thereby cooling the indoor area.

Energy generation and consumption budget Given the daily energy consumption per person accounts for 3 kWh, it is estimated that the annual energy consumption for the three shelters will add up to 17,520 kWh. By consolidating the above renewable energy generation sources, an energy generation and consumption budget is concluded as follows: 15

Table 4.1 the energy generation and consumption budget (Source: Design Team) Total annual renewable sources generated

Total annual energy consumption

Sources

Sources

Energy generated/saved (kWh/year)

Hybrid Eco-roof

Energy consumed (kWh/year)

Household

Solar energy

17,520

43,088

Wind turbine

52,56

Kinetic energy from falling raindrops

3,591

CO2 fixation technology Liquified methane

9,041

Total 60,976

Total 17,520

Net energy generation 43,456

As shown in the above table, the Hybrid roof and the CO2 fixation technology is able to produce sufficient energy for household consumption and energy backup. The excessive energy produced, which accounts for over 43,000 kWh, can be exported to the Singapore electricity grid for feed-intariffs.

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VI.

Smart Water Use Rainwater harvesting Singapore receives as much as 2100mm of precipitation annually. In order to capture the valuable freshwater which is otherwise being discharged back to the ocean, rainwater will be harvested as the major potable water source under prudent treatment. As shown in Figure 4.1, rainwater harvesters are situated along the edges of the roof to collect all rainwater fallen onto the shelters.

The rainwater will be used primarily for two purposes - one being a cooling agent to cool down the CO2 fixation technology device, while the other to be used as potable freshwater supply for the households.

The volume of rainfall harvested was estimated by using the equation below (Tong, 2016): Vrain = AC * I * CR Where AC = roof area (i.e. 269.2 m2); I = annual precipitation volume (i.e. 2.1 Litres); CR = constant (i.e. 0.85) As a result, an estimation of 480m3 of rainwater can be collected onsite, which is equivalent to 480,000 Liters.

Water-efficient installations Various water efficient devices such as aerators, water efficient washing machines and shower heads will also be installed in the shelter to reduce water consumption. According to the specification of these water efficient installations, about 220,000 liters of freshwater can be saved per year in the three shelters.

Waterless flushing In addition, since all human waste is converted into biogas and fertiliser on-site through an anaerobic digester which does not require flushing water, a significant amount of water can then be reduced. For instance, the Loowatt’s odourless, waterless and energy-generating toilet designed by a UK-based firm is a solution to reducing water consumption by human and transforming human waste to valuable by-products. The design of the toilet is shown in Figure 5.1 and 5.2 below. The hygienic waterless toilet system adopts a sealing mechanism to concentrate and push human waste into a biodegradable liner. When the toilet is flushed, the liner is pushed through the sealer to keep the waste within the storage tank. The “cartridge” is emptied constantly and the waste is transferred to an anaerobic digester where the waste and biodegradable liners would be converted into biogas and fertiliser (Riley, 2014).

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Figure 5.1 Loowatt’s waterless toilet (Source: Riley, 2014)

Figure 5.2 Advertising diagram of Loowatt’s waterless toilet (Source: European Union, 2016) The waterless toilet has been tested and launched various pilot projects in the UK and Madagascar, proving its feasibility and success as a ground-breaking approach to efficient treatment of human waste (Riley, 2014). Mobile and transferable models of Loowatt’s waterless toilet have been tested in campsites, suggesting its potential to be adopted in the Subject Site in Singapore as a pioneering waste-to-energy human waste treatment system for residences.

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Figure 5.3 The application of Loowatt's waterless toilet located at campsites (Source: https://www.youtube.com/watch?v=lU9ZhT3G8Po)

Greywater reuse and treatment Greywater is inevitable and would also be discharged otherwise if not being reused. In Green Cradle, all greywater produced, which accounts for 70% of the water consumed in the household, will be reused as irrigation water for the community garden and the green living wall on the facades of the shelters after initial treatment as shown in Figure 5.1.

Figure 5.1. The cycle of water recycling in the Green Cradle (Source: Design Team) 19

Water source and consumption budget Given the daily water consumption per person accounts for 70 Liters, it is estimated that the annual water consumption for the three shelters will add up to 408,800 Liters. By consolidating the above water saving and rainwater harvesting sources, a water source and consumption budget is concluded as follows: Table 4.2 the water source and consumption budget (Source: Design Team) Total annual potable water generation and reduction (L)

Total annual potable water consumption (L)

Sources

Sources

Water volume (L)

Water harvesting

Water volume (L)

Household

Rainwater

408,800

480,165

Water saving measures Water efficient showerhead

60,000

Water efficient faucet

91,728

Water efficient washing machine

68,137

Minimal flushing

36,792

Total 736,822

Total

408,800

Net water gain 328,022

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Total annual greywater collection (L)

Total annual greywater consumption (L)

Sources

Sources

Water volume (L)

Household

Water volume (L)

286,160 Irrigation

Total

286,160

Total

Net greywater gain

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VII.

Green Living Wall and Community Garden In order to support subsistence farming and to reduce food miles associated with the food produce consumed on-site, several façades of the houses will be mounted with Green Living Wall.

Comprising of hydroponic farming modules that grows edible crops, the Green Living Wall maximizes water efficiency and acts as an insulator to cool down the indoor temperature. As mentioned above, human waste can be converted into fertilizers and in turn nourishes the Community Garden where residents can contribute together as a communal farm.

Aims Vertical greening in a community provides a number of benefits to both the environment and quality of living of its residents. Figure 6.1 below indicates the 4 major aims of the Vertical Living Wall in this project.

Figure 6.1 Purpose of Vertical Living Wall on housing facades (Source: Design Team) First, regarding cooling effect, the large surfaces of vegetation on the facades of the proposed houses acts as a layer to reduce heat penetration to the indoor environment. Photosynthesis of plants also further allow air replenishment and improve the air quality in the community. On the other hand, the plantation of various species, including flowers of different colors and characteristics will contribute to visual enhancement which promote the well-being of residents.

Last, the growing of edible crops via environmentally friendly methods e.g. hydroponics can allow residents to “plant on own natural and fresh food” with less use of pesticides and other chemicals.

Residents of different age groups can together enjoy the fun of living with the nature and understand more about the sustainable ways of growing crops. An eco-production and consumption chain produced can act as an exemplifying testing ground for the planning for future self-sustainable neighborhoods.

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Relevant Standards and Guidelines The “Handbook on Developing Sustainable Highrise Gardens” published by the National Parks Board of Singapore in 2017 provided comprehensive guidelines on vertical greenery in the country.

The 4 main types of vertical greening include (1) Cassette System, (2) Planter System, (3) Product System and (4) Support System, which are shown in Figure 6.2 below.

Figure 6.2 Types of Vertical Greenery (Source: National Parks Board of Singapore) With consideration of their maintenance cost and the types of crops desirable for the proposed community, the (1) Cassette System and (2) Planter System is proposed to be adopted for vertical landscaping purpose and food harvesting respectively.

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Vertical landscaping Structure Figure 6.3 below shows reference photos indicating the structure of the vertical landscaping wall for non-edible plants.

Figure 6.3 Reference photo of the Vertical landscaping wall (Source: http://greenisland.az/?lang=en)

Types of species The National Parks Board of SIngapore provides a list of recommended plant species for green walls for the country. With regard to the weather and climate condition of the Subject Site, to balance between the occasional shadow casted onto the landscaping wall subject to individual wall’s orientation towards the sun, and occasional rainy and sunny days on the site, and some of the landscaping wall may be sheltered , plant species that require moderate amount of sunlight and water are selected as the suggested species for the living wall (see Figure 6.4 below). Subject to the actual condition of the site if the project is commenced, the types of species can be further modified by residents according to their own interests.

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Figure 6.4 Suggested plant species (Source: Design Team) Food harvesting wall Types of species With regard to the warm/hot and humid weather of the Subject Site, warm season crops are considered suitable for the food harvesting wall for hydroponic farming. Hydroponic farming has a number of advantages over conventional planting, in terms of the more efficient use of space (can be planted on a wall), climate control, water consumption, benefits to health etc. The advantages of hydroponic farming are listed below (Max, 2019): Advantages of hydroponic farming 1. No soil is needed 2. Better use of space 3. Climate Control - Total control over the climate - temperature, humidity, light intensification, the composition of the air. Food can be grown all year round.

4. Water-saving - Plants grown hydroponically use only 10% of water compared to field-grown ones as water is recirculated. Plants take up the necessary water and runoffs are captured and will return to the system. Water loss only occurs in the evaporation and leaks from the system (but an efficient hydroponic setup will minimize leakage).

5. Effective use and control of nutrients 6. Effective pH control 7. No weeds, fewer pests and diseases 25

Figure 6.5 Recommended warm season crops that are suitable for hydroponics (Source: Design Team)

Figure 6.6 Illustration of the structure of the food harvesting wall (Source: Design Team) 26

The composition of the wall include bricks and cement wall derived by recycled plastic, air gap and cellulose layer as insulation and waterproof membrane. Water collected from rainwater will be pumped through the water pipes along the external wall. The frequency of irrigation will be regulated by a smart regulator with detectors immersed into the soil monitoring the humidity of the soil. Irrigation will be undertaken when the detector detects that the humidity of soil is insufficient.

VIII.

Use of Stackable and Recyclable Building Materials Underneath the hydroponic farming modules is where the stackable and recyclable bricks are laid.

Made from recyclable plastics, the bricks are light, cheap to produce and easy to install with the use of mortise and tenon. They are also waterproof and hence able to resist water seepage from the adhering hydroponic farming modules. Apart from that, recycled paper fibers as one of the components of the wall can also be the source of insulation.

Figure 6.7 and 6.8: Reference photos for the LEGO-like recycled plastic bricks (Source: https://inhabitat.com/lego-like-building-blocks-of-recycled-plastic-allow-colombians-to-buildtheir-own-homes/)

Figure 6.9 and 6.10: Reference photos for wasted plastic as the aggregate in cement (Source: https://www.oliverheatcool.com/about/blog/news-for-homeowners/what-exactly-is-cellulose-insulation/, https://inhabitat.com/plastic-concrete-repurposes-landfill-waste-into-building-bricks/ )

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Figure 6.11 and 6.12 Reference photos for cellulose insulation materials which comprises 80-85% recycled newsprint that are resistant to fire (Source: https://www.oliverheatcool.com/about/blog/newsfor-homeowners/what-exactly-is-cellulose-insulation/)

IX.

Domestic Waste Recycling Apart from recycling human waste on-site as mentioned in section 6 nearly all domestic waste will also be recycled. As shown in Figure X, the pre- and post-consumer food waste will be collected by the on-site composter within the household for treatment and composter. The resultant fertiliser will be used in the community garden and the green living wall to nourish the vegetation and landscape. In addition to food waste recycling, yard waste such as fallen branches and leaves collected from the community garden will also be treated and converted into fertiliser for domestic use.

Besides, a comprehensive recycling mechanism on different types of domestic wastes such as metal, plastics, paper, glass, electronic appliances, batteries, printer cartridges, and lightbulbs can also be recycled. They will be collected and transferred to the municipal waste recycling facilities for subsequent separation and reuse. However, reducing waste at source is the ultimate solution to reduce waste generation. A series of education programme and community engagement will also be provided within the Green Cradle to combat over-consumption, which will be explained in detail in the next section.

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X.

Sustainable and Co-living Lifestyle Sustainable behavior Energy and water efficient installations and hardware would certainly assist the community to achieve resource conservation and carbon reduction, however the Green Cradle is aspired to bring sustainability to a next level by inducing behavioural change through education and community engagement that the residents are able to practice sustainable lifestyle even outside of the Green Cradle and radiate the notion of sustainability to their friends and family.

A series of sustainability-themed events such as screening of documentaries; community workshops for making DIY eco-detergents and cosmetics that do not include microplastics and chemicals; cooking classes for organic ingredients; will be conducted to allow residents to interact and share sustainable best practices together.

In addition, a group of resident volunteers are recruited to ensure proper recycling and hence minimise waste generation by regularly monitoring the recycling facilities. Apart from encouraging proper waste separation, the team of volunteers will also participate in showing acts of kindness in their neighbourhoods, outside of the Green Cradle to instill ideas of sustainability elsewhere. In turn, they will be awarded with priority application for community events such as yoga and cooking class.

Co-living and co-working culture As shown in Figure 3.3, all ground floor areas of the shelters will be dedicated for community use, such as eating place, co-working space and areas for mild exercise. Being an emerging business style to reduce cost of office operation by sharing resources, the co-working culture can also be realised here at the Green Cradle. Apart from sharing office supplies, the co-working culture can also share and incubate business ideas encourage interaction between members of the community, and to spark innovation to further sustainability in our everyday life.

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XI.

Conclusion This report is submitted for Project Shea for a design competition of a robust prototype for future sustainable dwellings and communities. Background studies provide the foundation of formulating the vision, design principles and implementation mechanism of the design proposal. Due considerations on the international call for adopting green living and community design for strengthening relationships among members of the communities have been made. The proposed design - "The Green Cradle" aims to foster human-nature symbiosis, community bonding and identity building, as well as sustainability of human living and development.

"The Green Cradle" consists of 3 dwelling designs. The 3 designs provide differing space allocations and interior designs to encourage a mix of households to live with the nature, interact with their neighbors and contribute to promote sustainable lifestyle. Apart from comprehensive hardware that generates renewable energy, makes efficient use of household waste and water resources, and allow eco-friendly farming and landscaping features that enhance the living environment, software including the provision of semi-public-open-space for holding various social and community activities also promotes healthy living with strengthened community bonding.

To conclude, it is envisioned that "The Green Cradle" will be the incubator for sustainable urban living with the adoption of advanced green technology, innovative dwelling design that fosters human-nature interactions, and community planning and design model that bring members of the community together.

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XII. Reference Bravo, P. and Debecker, D., (2019). “Combining CO2 capture and catalytic conversion to methane”. Waste Disposal & Sustainable Energy, Vol 1, pp. 53 - 65.

European Union, (2016) “Periodic Reporting for period 1 - LOOWATT (European Expansion for Circular Economy Off-Grid Toilets)”, https://cordis.europa.eu/project/rcn/204361/reporting/de Max, (2019), “20 Advantages & Disadvantages of Hydroponics That You Should Know”, Green & Vibrant, https://www.greenandvibrant.com/advantages-disadvantages-of-hydroponics Meteorological Service Singapore, (n.d.). “Climate of Singapore” , http://www.weather.gov.sg/climate-climate-of-singapore/ National Parks Board of Singapore, (2017). “Handbook on Developing Sustainable Highrise Gardens, National Parks Board of Singapore”, National Parks Board of Singapore.

Riley, T., (2014). “Waterless toilets turn human waste into energy and fertilizer”, TheGuardian, https://www.theguardian.com/sustainable-business/2014/nov/19/waterless-toilets-turn-humanwaste-into-energy-and-fertiliser Viola, F. (2018). “Comparison among different rainfall energy harvesting structures”, Applied Sciences, Vol 8, pp. 955-970.

Tong C.W. et al., (2016). “Performance assessment of a hybrid solar-wind-rain eco-roof system for buildings”. Energy and Buildings, Vol 127, pp. 1028–1042.

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