Evidence Based Environmental Architecture- Wandle House Refurbishment and Extension

SCHOOL OF ARCHITECTURE AND CITIES MSc Architecture & Environmental Design MODULE: 7AEVD001W.2 Evidence-Based Environmental Architecture

Wandle House Refurbishment and Extension Following Passive House Guidelines

Group 4A Maria Degetau Yashkumar Mukeshbhai Patel Address Wandle House, Penfold Street, Church Street Estate, City Of Westminster, Greater London, NW8 8BG

2. INTRODUCTION AND SUMMARY According to the 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), it is predicted that the CO2 emissions are expected to increase to 15.6 billion t-CO2-e by 2030 (Sizirici, et al., 2021).

The Climate Change Act of 2008, has binded UK into assessing the risks arising from climate change regularly (Shahbaz, et al., 2020). Construction is among the leading industries contributing the largest carbon footprint (Sizirici, et al., 2021). In 2020, the UK's building sector generated about 11.4 million metric tonnes of carbon dioxide emissions (Tiseo, 2023). The emissions from civil engineering make up roughly half of all construction emissions, albeit they vary by sector. Buildings and construction-related emissions totaled 2.4 million metric tons, or 17% of all emissions produced by the construction industry (Tiseo, 2023).

The Evidence Based Environmental Architecture module aims to understand, analyse and strategise by designing a built structure applying the principles taught throughout the course. By critical analysis based on the results from the previous studies of the building, a better performing building is realised. The main objectives of the project are: ●

Understanding the climatic conditions in and around the site under study.

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Identifying the potential of the environment and its positive effects

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To put out a design that is supported by environmental data, employing methods to reduce or eliminate the environmental impact of buildings while ensuring the safety of users in both interior and outdoor areas.

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The project's location is within the City of Westminster, London. The area has a mix of land use with a predominance of residential uses and limited commercial and office space.

The mixed use spines on the Edgware road and the Church street are dominated by retail, residential and cafes acting as a district centre for shopping.

3. METHODOLOGY

The method of study is divided into different steps depicted in the illustrations below. At first, the background studies are conducted wherein the existing site and climate conditions are studied and the different challenges associated with it are analysed. Based on the findings and analysis of the previous studies, an understanding of the challenges of the site and the opportunities of for intervention are realised.

A design concept is then developed that guides the course of the project based on a framework that eventually forms the basis of the intervention.

The concept then evolves into a design considering the massing, project aims and program. The design development stage is where the conceptual design is accurately designed considering all the strengths and the constraints of the site.

The next step involves analysing the built form individually with a focus on the outdoor and indoor environmental studies by using various available tools and their impacts.

Finally the resulting intervention is tested for its building performance and a specific review is prepared as a result of the difference the with the intervention.

London has a temperate maritime climate, which historically can be characterized as having mild winters and temperate summers, with the prominent wind coming from the west (Britannica, 2023).

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Mean max: 28.55 ºC (aug) +6.49

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In London, as shown in graphs 2 and 3, the mean maximum temperature will be 25ºC during the month of August, and 28.55ºC respectively.

Meaning that if world leaders continue on the same track, investing in fossil fuels and non-renewable energies (amongst other important efforts) then, London's climate will change so dramatically that most of the buildings will need drastic refurbishment efforts to cope with the rising temperatures.

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In terms of temperature, the mean maximum temperature occurs during July at 22ºC, this is expected to change according to the Representative Concentration Pathway scenario 4.5 where the change in temperature by 2100 will be 2.4ºC, and with the RCP of 8.5 the temperature is expected to rise 4.3ºC globally. (Met Office, 2018)

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4. BACKGROUND STUDIES 4.2. London's present and future climate

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Chart 1. Present London's climate

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Chart 2. Future London's climate RCP 4.5

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Chart 3. Future London's climate RCP 8.5

4. BACKGROUND STUDIES 4.3. London's climate - Challenges

Existing building

Existing building + insulation

The typical building construction material in London over the years has been brick, which has a high thermal mass, this is generally a good property because it can store heat during the day, releasing it by night.

Because London's climate during winter is cold, people tend to heat their homes for many hours during the day.

This issue has been tackled by insulating the building fabric better to prevent the internal heat to escape through infiltration, therefore reducing heat loads significantly.

Colder indoor temperature

With climate change rapidly approaching, we need to evaluate if this strategy is the right one to reduce energy in the future climate.

As long as we have well-insulated buildings to cope with the cold months, we still need to account for good natural ventilation to allow the building to breathe during the summer period, especially during the coming years when the temperature can rise to 4.3ºC. The problem is that with higher temperatures, and not sufficient natural ventilation, the heat that the bricks are storing will remain inside the building causing the indoor temperatures to rise and probably making the energy demand go high again with the use of mechanical cooling devices.

Higher indoor temperature Fig 1. Insulation before and after

4. BACKGROUND STUDIES 4.4 Site History Church Street dates back to the 18th century, when it was first developed as Lisson Green, a tiny settlement to the east of Edgware Road. The construction of Regent's Canal began in 1812, and its completion resulted in a profound alteration in the area's character.

The previously rural community was quickly overtaken by dense residential housing, typically of poor quality.

The neighbourhood became extremely organized, with a tight grid of streets. Church Street provided a crucial east-west connection through the neighbourhood and began to accommodate the failed 'Portman Market' at the turn of the twentieth century (Westminster, 2017).

In the nineteenth and twentieth centuries, major infrastructural development had a tremendous impact on the area.

Marylebone Station was built near the end of the nineteenth century, cutting off connections to the east.

Access and movement issues became worse further by the construction of the Westway flyover in the 1960s.

The current architectural style in the neighbourhood can be attributed primarily to rebuilding following World War II bomb damage. Many of the housing complexes present now replaced the network of streets once associated with the area (Westminster, 2017).

The Lisson Grove conservation area, which is located around Bell Street and Lisson Grove, is slightly larger.

The style is largely Georgian, Victorian, and Edwardian residential terraces, but a number of institutional buildings break up the formality of the blocks and add visual appeal. The conservation area contains one Grade II* listed building and several Grade II listed properties (Westminster, 2017).

Although the majority of the land is not covered by a conservation area, a few of important ones are located along the boundary (Westminster, 2017).

4. BACKGROUND STUDIES 4.5 Urban Context The area is served by three major transportation hubs: Marylebone, Edgware Road, and Paddington stations.

Several roads, including Edgware Road and Lisson Grove, connect it to central London. The location is close to Regent's Park and the Regent's Canal (Westminster, 2017).

The bustling Edgware Road, a popular road and vital arterial route into central London, borders the western boundary of the town. Edgware Road is a major retail and commercial sector, with a diverse range of stores, garages, and a large proportion of restaurants and cafes known for its Middle Eastern cuisine (Westminster, 2017).

The National Railway line servicing Marylebone Station and Lisson Grove, a busy B-road with largely residential houses, border the area to the east, with pubs and shopping appearing to the south of the road. The rail line, in particular, inhibits access to Church Street and forms a barrier to regions to the east, such as Regent's Park. The nature of the built environment, which backs onto the rail line, and a lack of bridge crossings further limit accessibility, leaving Rossmore Road as the only clear path to places to the east (Westminster, 2017).

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4. BACKGROUND STUDIES 4.6. Existing Building

The existing building is located in the Borough of Westminster in London, with the following characteristics:

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2 Level 12.55 m 1 Level

Location: Wandle House, Penfold Street, Church Street Estate, City of Westminster, Greater London Authority, NW8 8BG Building Type: Social housing Number of Floors: 4 Construction Year: 1968 - 1975

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Wandle House Elevation

Context Section

Context Plan, Wandle House

4. BACKGROUND STUDIES 4.7. Existing Building

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The building's walls build-up is constructed mainly in brick, the frame and structure are of concrete and the original windows had single glazing with a proportion of 1.25m x 2.65m.

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It is composed of four levels with duplexes accessing from the ground floor level and the second level through a corridor.

The configuration of the duplexes is by a stacked level formation, each of the levels has a height of 2.8 meters

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Facade Penfold Street

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Level 3-4

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Level + 6.5 m 12.1 m 10.6 m 9.3 m 8.0 m 6.5 m 5.2 m

Level 2 Short Section

Level + 5.2 m

5. SITE ANALYSIS

Wandle house is oriented in the South-east-North-west direction. The longer edge facing the southwest. The prevailing wind direction is from the south west.

The sun’s angle is at a maximum of 60 degrees during the summers increasing the temperature to about 25 degree celsius. The minimum angle of the sun is between 10-15 degrees during the winters that reduces the temperature below 0 degree celsius.

5. SITE ANALYSIS 5.1 Environmental Analysis Using climate studio analysis tools; solar radiation, wind analysis and shadow analysis was conducted to analyse the existing built condition.

In case of solar radiation, May to September recorded the dry bulb temperature to be higher than 20 degree celsius whereas November to April recorded temperatures lower than 15 degrees.

The dominant wind direction is from south-west.Due to a building opposite the Wandle house the wind speeds on the street in between is comparatively lesser as compared to the other two streets that record a speed of about 2.5m/s.

The findings of the shadow analysis suggest that, during winters the shadows are greater as compared to the summer months.

6. BRIEF 6.1. Housing Problems in London The living situation in London has always been developing, today being one of the most interesting cities to work or to study, London has a real housing problem when people from many different backgrounds and interest are looking for an accommodation that fits their needs, but more often than not this does not happen.

People looking to rent Rooms to rent available

Typical family arrangement

(Little Room, 2023)

The typical arrangement consisted on a family house equipped to accommodate around 4 people or more.

This family houses now are often being refurbished to accommodate more private bedrooms for renters. The result is poor quality spaces, bad illuminated and very badly ventilated with no space for socializing.

This is why new typologies are so interesting especially for the point of view of refurbishment.

The new typologies that we will be focusing on are Co-living and Co-working.

Modern living arrangement

Co-Living, could be defined as a communal rental housing, compromising private bedroom units (generally in large scale) and large amounts of shared spaces and quality amenities. It is an affordable choice for people who don't want to buy and need flexibility, also it creates a valuable community that many professionals are begging to seek.

Age profile: 18-35

Age varied, independent working or studying people

CO-LIVING

15,500 people - 2020 70,000 people - 2025 (Spotlight, 2023)

(The guardian, 2021)

CO-WORKING

1,274 coworking spaces

Startups Freelancers Small businesses

Rising real estate, change work patterns, remote working preference

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Co-living Modern form of communal living, individuals share common spaces like kitchen, relaxing spaces and services, with a private space for the sleeping area.

1. Shared space 2. Privacy 3. Shared amenities and services 4. Flexibility 5. Networking / community 6. Security 7. Affordable housing

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6. BRIEF 6.2. Co-living & Co-working - Precedents

Lyvly, London

Co-working Gravity, London

wework , London

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Shared workspace where people from different companies share a common space. Operated by a third person, offering a range of services or facilities.

1. Shared workspace 2. Flexibility 3. Community 4. Amenities 5. Accessibility Big scale coworking can accommodate hundreds of people (Wework in London has 1,000 members), with a more diverse range of professionals.

Small scale coworking in London typically caters to around 10 to 50 members, creating a more personalized environment.

Huckletree, London

The Brew, London

Second Home, London

The Pill Box, London

Shared space Networking Community Accessibility

6. BRIEF 6.3. Concept After analyzing the characteristics of each typology, there is a clear overlap of common features between co-working and co-living.

These attributes are transformed into architectural elements that foment networking, community and safety.

Happening at the same time in the same place, making the proposal accessible for more people, reducing commuting hours especially if the project is in a high value site like central London.

Co-living

Co-working

The goal is to mix all the typologies together to foment what we believe are positive attributes that create community and a sense of wellbeing. By mixing the shared spaces with the “typical family house” we are diversifying the age group, professions and occupations to create a bigger and stronger community that can evolve with time.

Bigger and stronger community Family house

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Family house

7. DESIGN DEVELOPMENT 7.1. Strategy -Massing and refurbishment Existent Building

Refurbishment 1.

An extension of 2 meters of the corridor towards the main facade in Penfold Street. This will allow the corridor to be less dark, more ventilated and the entrances towards the flats will be more frank.

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Refurbished Flats

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An extension of the existent core towards the roof level. Also, the addition of a lift on both side of the building in order to guarantee the accessibility of people with different mobility.

The addition of the typology “Co-Living” is introduced at the roof level. These semi-detached constructions are meant to have only one floor, in order to make accessibility a priority. ● Orientation: South-West f Taking advantage of the difference in levels on the roof area, the typoly “Duplex” is introduced.

Making the most out of the square meters, the construction will be design in two half levels. ● Orientation: South-West The volumes that will hold the “Co-Working” spaces are left closer to the corridor and main access, creating a play of volumenes and free spaces for gardens. ● Orientation: North-East

Core Extension

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7. DESIGN DEVELOPMENT 7.2. Environmental challenge

Plan. Existent duplex layout

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Refurbishment The first strategy that we will tackle is the refurbishment of the second and third floors. This is because after analyzing these spaces we could see clearly that for this building to adapt to the future the quality and design of the spaces need to be addressed.

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Closed, narrow layouts: the existent duplex layout (as studied previously) was lacking natural ventilation and uniform daylight through the spaces, due to the narrow and compacted layouts.

Dark and narrow corridor: the access to the second-level duplexes is through the open corridor on this level. The corridor was shown to be a big issue for the residents because of its cold temperatures and strong wind currents.

Insulation and material selection: the building materials of the existing building is lacking insulation to prevent infiltration.

2 Image 1. Refurbishment spaces

Image 2. Corridor second level, internal view

Massing A.

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South-West facade: At the begging of the massing exercise we concluded that our biggest issue for this design would be overheating at the southwest facade.

As we can see from the comparison between Images 3 and 4, the difference is substantial.

Material selection: the overall material and benchmark selection for this new building needs to be taken into account in order to be consistent in the design.

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Image 3. Inicial massing - solar irritation study, Southwest Facade

Image 4. Inicial massing - solar irritation study, Northeast Facade

7. DESIGN DEVELOPMENT 7.3. Massing by informed design

Winter 9.00 AM

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Massing A.

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Overshadowing other buildings in the context The first strategy that was taken into consideration to start massing the new building was overshadowing, we need to be mindful of the context that surrounds us to not create more problems for other people as we design. This exercise showed that by having different sizes of volumes at different levels we created less shade on the building at the courtyard of the compound.

The study was evaluated in the month of December because this is when solar irradiation is most precious in the climate of London.

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Autumn 09.00 AM

Overexposure: the exercise consisted in placing different volumes with different configurations in order to simulate how much solar irradiation we will have in each case. We can see from the results in graphs 1-3 how the total hours of solar exposure are becoming less when the volumes tend to overshadow each other.

Image 1. Series of overshadowing analysis - December

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Total hours - 73 kWh/m2

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Total hours - 69 kWh/m2

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Total hours - 52 kWh/m2

8. PROPOSED DESIGN 8.1. Refurbishment - Plans and Facade

45 m .

16.2 m 14.9 m

The proposed retrofit strategy is applied on the second and third floor of the housing complex as they were considered to be the least efficient in terms of passive strategies, energy performance and overall comfort.

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In order to bring in more daylight and ventilation, the plans are proposed to be more open-plan typology plus an addition of shaft in between these units would enhance the passive performance of the building.

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The structural system highlighted in black will stay intact and only the partition walls would be incorporated with added insulation highlighted in red will encompass the new built system, resulting in overall energy savings of the building.

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New built Existing walls

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8. PROPOSED DESIGN 8.2. Extension - Plans and Sections

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Extension

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The proposed extension on the roof intends to house the three typologies studied previously.

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First of all the challenge was to design the new buildings but to take into consideration the layout and the needs of the refurbished flats on the lower levels. This meant designing accordingly to the small courtyards below to allow ventilation and daylight to come into the space of the lower flats.

As we can see from Section 1, the red walls indicate the newly built and the black lines indicate the existing walls. The existing structure was taken into consideration in order to preserve as much as possible the structure and to reduce waste.

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Section 1. New and existing

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New built Existing walls

Level + 10.6 m Plan 1. Corridor level

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Level + 13.4 m Plan 2. Roof Section 2. New and existing

Level + 12.1 m

8. PROPOSED DESIGN 8.3. Bioclimatic Section Extension The section describes the overall performance of all the strategies implemented in the proposed design with addition of space quality and densification on the top floor.

The building facing the South-west direction on the Penfold street has the best case scenario for cross ventilation as well as stack effect through shaft giving good thermal comfort indoors.

Strategies of co-living and co-working spaces incorporates a new character to the building with addition of lift shafts on either side of the complex giving accessibility to all.

Existing solar panels are conserved and retrofitted on the top floor at 45 degrees south orientation to reduce the energy demand through renewables.

45 existent solar panels South orientation

9.1

INDIVIDUAL STUDIES

9.1.1 Refurbishment of existing floors PROPOSED LAYOUT: The Proposed Layout on the Second Floor (Lower Floor) opens up to the South-West direction which is also the dominant wind direction.

From the Existing Layout, each unit is further divided into two units comprising of 2BHK module each, sharing a common shaft/court which helps in ventilating as well as bringing in more daylight into the depth of each unit.

The facilities are shared that resonates within the apartment and within the adjacent apartments. This concept is in accordance with the co-living framework.

The new layout accommodates 14 apartments split across two floors. The division of spaces between adjacent apartments is such that it ensures a sense of privacy and segregation in terms of the function.

The top floor has been extended onto the front corridor to accomodate a bedroom ensuring sufficient space within the apartment.

The two apartments that share the common court have a common main entry that bifurcates into two upon entering the foyer. The main entries of both the apartments are separate and latent from the main corridor to ensure for privacy.

Upon entry there is a level difference that leads to the apartment. In terms of the spaces, the typology 1 enters into a bedroom spaces with another flight of stairs directing upwards to the living, kitchen and another bedroom. The lower bedroom could also be occupied by a bachelor that uses the shared facilities of the apartment. Typology 2 opens up into a common living and kitchen with two double bedrooms on the landing and the top floor.

The kitchen and living has a significantly large opening that brings in light into the apartment. All the bedrooms have openings that light up and provide ventilation, The double single bedrooms are designed to accommodate families of four.

9.1

INDIVIDUAL STUDIES

9.1.2 Detailed units There is an attempt to try and achieve ventilation in every part by introducing controlled openings in the kitchen, living and dining areas. The spaces are divided efficiently on different levels as shown in the illustrations. The levelled planning of the built form is in coherence with the existing levels to reduce the carbon emissions caused due to major refurbishment changes, The design has evolved to perform better.

A majority of the spaces open up into the shared court to allow for daylight and ventilation by applying the double atria strategy into the apartment. This also ensures interactions between the different residents and the social well being of the residents.

9.1

INDIVIDUAL STUDIES

9.1.3 Sun Path analysis for cold hours The following diagrams indicate the sun path and the shadow analysis of the building during different seasons and at different times of the day.

The floors under study receive sunlight almost all throughout the year when the sun’s angle is significantly large.

As evident from the diagrams shown, the second floor does not receive any sunlight during the winter evenings when the sun’s angle is as low as 5 degrees at approximately 4pm .

These results drive the analysis when the studies are carried out for the performance of the building in the worst conditions.

During all the months the third floor does receive a considerable amount of sunlight.

9.1

INDIVIDUAL STUDIES

9.1.4 Useful Daylight Illuminance- Second floor (Winter- Dec 21) The second floor of the proposed layout is better performing in comparison to the existing layout in terms of its useful daylight illuminance.

As shown in the diagrams, during the course of the day at different times the proposed apartment design receives an illuminance between 300-3000 lux which falls under the acceptable range, On the contrary the existing layout has lesser illuminance making it completely failing at 3pm during a Winter Day .

9.1

INDIVIDUAL STUDIES

9.1.5 Daylight Autonomy - Second floor (Winter-Dec 21) The new layout is better performing in terms of receiving more autonomous daylight during the day indicating as compared to the existing layout that is 50% of the time the daylight illuminance is greater than the target illuminance.

It is observed that more areas have a higher daily autonomous in the proposal with a majority at 12pm resulting in fewer darker areas throughout the day as compared to the existing layout,

9.1

INDIVIDUAL STUDIES

9.1.6 Useful Daylight Illuminance- Third Floor (Winter- Dec 21) The third floor of the proposed layout is better performing in comparison to the existing layout in terms of its useful daylight illuminance.

As shown in the diagrams, during the course of the day at different times the proposed apartment design receives a considerable amount of illuminance between 300-3000 lux which falls under the acceptable range, The combination of supplemental and acceptable throughout the day with a very little proportion of excessive illuminance ensures adequate light throughout the day as compared to complete darkness in winters at 3pm. .

9.1

INDIVIDUAL STUDIES

9.1.7 Daylight Autonomy - Third floor (Winter-Dec 21) The new layout is better performing in terms of receiving more autonomous daylight during the day indicating as compared to the existing layout that is 50% of the time the daylight illuminance is greater than the target illuminance.

It is observed that more areas have a higher daily autonomous in the proposal with a majority at 12pm resulting in fewer darker areas throughout the day as compared to the existing layout.

9.1

INDIVIDUAL STUDIES

9.1.8 Natural Ventilation ( Under floor stack Vs Rooftop stack)

Rooftop Ventilation

For understanding the wind flow movement during the harsh summer months an Optivent Study was analysed for the month of July.

As evident from the diagrams shown in the Optivent study, both the under floor stack and the rooftop stack ventilation are performing efficiently.

However, the area required according to the apertures data shows that the under floor stack ventilation needs an effective area of 5.4 sq.m which is double the area required for rooftop stack ventilation making it more desirable.

Under floor Ventilation

9.1

INDIVIDUAL STUDIES

9.1.9 Wind flow analysis (Computational fluid dynamics) - Warm Hours The figures show the directions of windflow. It is evident how the wind travels up into the rooftop stack. The provision of openings on both the sides ensure the flow of wind into the apartment.

The change in temperature is also evident as the the temperature reduces inside the stack indicating heat loss through it.

The wind flow analysis of the second floor with the wind entering from the main door and gushing out from the openings of both the floors is shown. Similarly the dynamics of the third floor is also depicted with the wind entering from the bedroom window and gushing out from the openings on the opposite side. The stack plays an important role in this.

9.1 INDIVIDUAL STUDIES 9.1.10 Warm hours indoor performance

Living + Kitchen

The graph illustrates the comparison of dry bulb temperature (DBT) between external DBT, existing DBT and proposed DBT with reference to the ASHRAE adaptive comfort band.

The first graph demonstrates how the temperature in Living & Kitchen area is higher than the external temperature in the existing scenario, whereas the proposed condition with the help of good cross ventilation achieves lower temperature than the external temperature resulting in the comfortable DBT during warm hours.

Similarly, the second graph also shows how the temperature inside bedrooms achieve comfortable DBT compared to the existing scenario which had higher DBT inside bedrooms during warm hours.

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External DBT Proposed DBT Existing DBT

Bedrooms

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9.1 INDIVIDUAL STUDIES 9.1.11 Annual DBT and energy performance

Cold season (October- April)

Temperature (°C)

The resulting heating loads are 41.125 kWh per sq.m which is higher than the LETI heating demand benchmark but is significantly lower than the existing scenario wherein the heat loads are quite high making the building more sustainable.

Cold season (October- April)

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The adjacent graphs depict the temperature variations throughout the year and the heating requirements in accordance to it.

It is evident from the study that from April to September the proposed layout would not require any mechanical heating.

Warm season (April-September)

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Applied Values

Infiltration rate - 0.1 ach Ventilation 0.06 ach

Recommended Value (as per LETI guideline)

Living Room Floor area

60 m2

Bedroom

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41.125 kWh / m2

External Temperature

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LETI heating demand benchmark

400 Heating Load (W)

Wall - 0.275 W/m2.oC 5/8 in. gyp board R-11,3-1/2 in. batt insulation 1/2 in. fiberboard sheathing R-5, 1 in. insulation board Wall air space resistance 4 in. brick Glazing - 1.274 W/m2.oC 6mm SG planilux clear 12mm Argon 6mm SG cool-lite

92087 W

*LETI, Climate Emergency Design Guide, 2021

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Walls - 0.18 W/m2.K Floors - 0.18 W/m2.K Roof - 0.12 W/m2.K Glazing - 1.00 W/m2.K

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9.1 INDIVIDUAL STUDIES 9.1.12 Refurbishment Conclusions The proposed layout has applied an open space planning strategy that has opened up the internal spaces inviting more light and ventilation into the apartment. An attempt to densify the existing layout without compromising with the space quality and efficiency has been made by combining the principles of co-living and shared spaces.

The design ensures maximum light into the building leaving minimum dark spots. The useful daylight illuminance and the daylight autonomy both concluded that the light received by the proposed apartments during the entire year is much greater and falls between the acceptable range for most part of the year.

Introduction of stack ventilation ensured an efficient wind flow throughout the building through the common court. The strategic placement of the openings gave rise to cross ventilation from one end of the apartment to another.

Furthermore, the warm hours indoor performance of the built indicates that due to the cross ventilation the living, kitchen and the bedroom all fall under the DBT comfort band post retrofitting. The heating loads in comparison to the LETI are higher but the proposal has successfully reduced the existing heating loads.

In conclusion, post retrofitting of the existing the built fabric; the proposal has successfully increased the built density of the building, increased the autonomy and the illuminance which seemed to be the major drawback of the existing structure, has improved the ventilation and the wind flow of the building and has significantly lowered the heating loads.

In totality, this built form post retrofitting is a better performing building.

9.2

INDIVIDUAL STUDIES

9.2.1 Roof Extension Design The new build extension on the roof will hold 3 different typologies, following the concept stage on the brief.

1.

Co-living: formed by 4 private bedrooms with a bathroom each, an open and shared kitchen and a social area as indicated in the precedents. The bathrooms are ventilated using the shaft that connects towards the courtyard on the lower level flats. Taking advantage of the stack ventilation, we can ensure the proper ventilation of these spaces. ● Bedroom 1 - A larger version of the co-living typology, which has a private kitchenette, allowing the user to have more privacy in the daily routine. Also, it has cross ventilation through the main facade in the southwest towards the opposite window at the back courtyard in the northeast facade.

Co-working

Common area

Co- Living

Bathroom

B1 Bathroom

B2 Bathroom

B2 B1

Bathroom

Duplex 1.

2.

Co-working: 12 m2 layout facing the corridor in the northeast facade. The co-working typology can hold up to 26 people distributed in 4 rooms along the corridor. With high windows facing the north-west to ensure uniformed daylight with no glare, using these same apertures to have single-sided ventilation if required.

Typical Duplex: (further analyzed in this chapter)

Typologies 1 and 2 are placed on the same level landing of the stairs and lift, in order to ensure access to people with limited mobility.

On the other hand, Typoly 3, takes advantage of the difference in levels of the existing building, forming a compact duplex that can hold 1 or 2 bedrooms with an open living room and kitchen.

Existent

9.2

INDIVIDUAL STUDIES

9.2.2 Typology No. 3 - Duplex Option 2

Taking into account the time for this case study, we will only be focussing on the third typology of the roof extension.

Going more into detail, proving the strengths and weaknesses of the proposed semi-detached building.

3.1 m

Terrace

36.5 m2

2.8 m 23.3 m2

The objective of this study is to apply the environmental design tools taught in the module “Evidence-Based Environmental Architecture” to inform the design of the duplex. Evaluating each space's performance and undertaking the necessary modifications to ensure the best space possible in the context and following the LETI guidance for a small detached new build.

Bedroom

Option 1

14.5 m2

The typology is formed by an open living room and kitchen placed on the lower half level, a bathroom placed on the access level and 1 or 2 bedrooms placed on the upper half level.

The structure is proposed in timber, to ensure the most lightweight construction possible due to the unknown structural condition of the existing building. Also, because timber has a lower carbon footprint than any other heavyweight structure.

Living Room

36.5 m2

5.5 m

The views are the main concept and value of this typology, intending to have the biggest windows we possibly can allow.

To understand the limitation of this design intent and to further recommend a typical window size for these conditions and presets.

Desired view

Finally, a flexible design regarding the bedroom number is proposed, taking into account that this type of housing typically tends to grow over time, and the aim is to have the option to extend.

Kitchen

9.2

1 Level

INDIVIDUAL STUDIES

Air Flow Rate

With the help of Optivent, two strategies were taken into consideration to size the inlets and outlets of the Duplex.

2.

Strategy: Atria (single cell) ventilation The design of the space on the first level has one single window and two double windows facing southwest, where the predominant wind direction is coming from. Meaning that a considerable amount of fresh air will enter through the openings, and to cool the space and create a comfortable environment, the air needs to be exhausted properly. The proposed outlet is on top of the stairs, creating a clear airflow path in the back and centre of the duplex. Because this outlet is on a higher level than the inlets of the first level, we call this type of ventilation atria, when the air is exhausting upwards.

Strategy: Cross ventilation For the bedroom and bathroom, cross ventilation is proposed. Because of the narrow floor plan, we can be sure that the air that will come through the inlet in the southwest facade will travel through the room and exhaust from the outlet at the opposite side of the room (northeast).

m/s

2 Level

Buoyancy driven (No air flow taken in consideration)

1.

Required fresh air

Operative Temperature (°C)

52 DD July 15 18 °C 1 (m/s) 1 SW

Required for cooling

1

2

Output

Achieved

Adaptive Comfort Band 2 Level Bedroom

1 Level Living Room

Air Flow Rate

m/s

Latitude: Month: Hour: Prevailing mean outdoor temperature: Meteorological Wind Speed: Terrain data:

2 Level

Required fresh air

Operative Temperature (°C)

To ensure the correct wind flow for the space to cool during the warm season first, it was necessary to analyze the natural ventilation in the proposed area during the warmest month in the year, which is July.

Using the following considerations:

Buoyancy driven (No air flow taken in consideration)

9.2.3 Inlet and Outlet Sizing

Required for cooling

Achieved

Adaptive Comfort Band 1 Level

9.2

INDIVIDUAL STUDIES

List 1. Proposed building constructions Wall - 0.125 W/m2 °C Gypsum Glass fibre R-30 Insulation Gypsum board Stucco

9.2.4 Building Construction Presets The building constructions were determined, following LETI recommendations. Using mainly timber (locally sourced), different layers of insulation, and triple glazing for the windows.

Floor - 0.08 W/m2 °C Plywood Batt insulation R-30 Insulation Wood joist floor Plywood joist floor

We know that triple-glazing windows have a bigger carbon footprint because of the amount of material it requires for their manufacturing. On the other hand, it has better insulation properties helping reduce the amount of energy needed to heat or cool a building. *(For the purpose of this exercise we will follow LETI guidance which uses triple glazing )

Cooling and heating strategies ● Cooling Thermostat - Natural ventilation Aiming not to have any mechanical cooling inside the proposed building, due that London's climate has mild warm summers with strong winds which with a proper ventilation strategy can be sufficient to cool the spaces. ● Heating thermostat - 18°C Another important preset to take into account is the thermostat threshold we will determine for the energy simulations. According to the UK government, the ideal temperature range for indoor spaces during the winter months is from 18°C to 21°C. Therefore the thermostat is set to 18°C, meaning that inside the Duplex every time the indoor temperature starts going below 18°C, the heating will be turned on to that temperature.

Occupancy schedule Aiming to reduce the heating load as much as possible, a schedule with the user's occupancy was implemented by the hour. Following the logic that whenever the user is not inside the space, then the room won't need to be within comfort temperature and the heating will be off.

List 2. Recommended building U- Values

Roof - 0.06 W/m2 °C Plywood Batt insulation R-30 Insulation Wood joist floor Insulation board Roof build up Plywood joist floor

*LETI, Climate Emergency Design Guide, 2021

Image 1. Inicial duplex condition

Glazing - 1.2 W/m2 °C Triple glazing

List 3. Internal conditions by room

Common area Occupancy sensible gain - 7.0 W/m2 Occupancy latent gain - 1.0 W/m2 Equipment sensible gain - 6.0 W/m2

Image 2. Occupancy schedule Bedroom Occupancy sensible gain - 5.0 W/m2 Occupancy latent gain - 1.0 W/m2 Equipment sensible gain - 5.0 W/m2

Bathroom Occupancy sensible gain - 15.0 W/m2 Occupancy latent gain - 2.0 W/m2 Equipment sensible gain - 0.0 W/m2

1.2 m

9.2

1m

Small size window 1 m x 1.4

INDIVIDUAL STUDIES

9.2.5 Window Sizing - Double glazing

External temperature

In order to size correctly the windows in the duplex, a comparison was made between a smaller window size of 1m x 1.4m and a larger window size of 1.2m x 2.2 m.

Both of them will be analysed using double glazing with a U-value of 1.8 W/m2 °C. Each comparison will be done during the month of July (warmest month in the year) and February (coldest month in the year).

Living Room 25°C

Warm Period

20°C

15°C

Bedroom 25°C

20°C

15°C

Living Room 20°C

0°C Temperature (°C)

Cold Period

10°C

Bedroom

20°C

30°C

10°C 10°C

Cold - February (day 40-47)

Temperature (°C)

Hot period Living Room The DBT of the room with the larger window remains a little higher than with the smaller window throughout the month of July ● Smaller window is prefered Bedroom The bigger window size keeps the DBT of the room warmer throughout the entire month than the smaller size window. The difference between temperatures is considerable due to the smaller size of the room ● The smaller window is preferred to keep the room temperature lower.

Cold period Living Room When the external temperature goes below 0°C, the difference between the bigger window and the smaller window goes from 1-2°C. When the external temperature is between 0-10°C, the DBT of the area with the larger and smaller window tends to be the same. ● The larger window is preferred due that heats the space better during the cold season Bedroom When the external temperature goes below 0°C the DBT of the space with the smaller window size is higher than the space with the larger window during the day. ● Smaller window is preferred due it allows the space to be warmer

Large size window 1.2 m x 2.2

1.4 m 2.2 m

Warm - July (day 185-192) 0°C

1.2 m

9.2

1m

Small size window 1 m x 1.4

INDIVIDUAL STUDIES

9.2.6 Window Sizing - Triple glazing

Large size window 1.2 m x 2.2

1.4 m 2.2 m

External temperature

The next comparison will follow the same logic as before, between the same smaller (1m x 1.4m) and a larger window (1.2m x 2.2 m). Only that now, both of them will be analysed using triple glazing with a U-value of 1.1 W/m2 °C, as specified in LETI recommendations.

Cold Period Living Room When the external temperature goes below 0°C, we can see that the larger window keeps the temperature of the room higher during the day, and lower during the night.

Because the users won't be occupying the living room during the night, a larger window is preferred. it will heat the space better during the day when the occupants will enjoy the advantages.

Bedroom The smaller size window keeps a higher temperature throughout the month of February, especially when it gets lower than 0°C and during the night when the occupants will be asleep.

A smaller window is preferred.

30°C

Warm Period

20°C

10°C

Bedroom 30°C

20°C

10°C

Living Room

20°C

10°C

Cold Period

Hot period Living Room In both scenarios, the DBT of the room maintains its temperature constant with the external temperature throughout the entire month. ● No preference in aperture size Bedroom The bigger window size keeps the DBT of the room a little higher than the smaller size. ● The smaller window is preferred to keep the room temperature lower.

Living Room

0°C

Bedroom 20°C

30°C

10°C

10°C

Cold - February (day 40-47)

Warm - July (day 185-192)

0°C

9.2

Room DBT

INDIVIDUAL STUDIES

30 °C

9.2.7 Wind Flow Analysis: DBT

20 °C

Wind Direction In

In order to further analyze the Duplex throughout the warm period, and also to prove what was said in the previous Optivent analysis. A wind flow analysis was done on the same day in the months of April, July and September. To determine if the resulting windows and outlet sizes in the previous studies are allowing optimal ventilation, resulting in the passive cooling of each space.

Out

24 °C

35 °C

15 °C April

We can say that even though the wind direction is not always coming from the South West (dominant wind direction) because of the position of the building and due to there being no obstructions, the wind can enter the space and cool it maintaining a constant temperature of 20 °C throughout these three typical warm days.

April

July

September

10:00

10:00

10:00

13:00

13:00

13:00

17:00

17:00

17:00

There are 3 main inlets and 3 main outlets in the studied building.

1 3

2

2 3 1 Outlet Inlet

After analyzing each of the flows, we can say that: 1.

Inlet 1 receives the most wind coming inside, which exhausts from outlet 1 (the largest size of outlet as per Optivent recommendations) 2.

Inlet 2 lets the wind in towards the bedroom and works with outlet 2 to create cross ventilation through the space and ensure proper ventilation.

3.

Inlet 3 is to ventilate the bathroom, where it takes advantage of the orientation towards the predominant wind direction (southwest) and cross-ventilates the space with outlet 3.

July

September

9.2

INDIVIDUAL STUDIES

9.2.8 Wind Flow Analysis: Velocity m/s

Floor Plan Level 2

A further study was made to test the wind flow, now focusing on the velocity and direction of the wind inside the space.

Using Computational Fluid Dynamics (CFD) and assuming a typical warm day when the external temperature is around 19° C, and the wind speed is 1.2 m/s.

There can be many different ways the duplex ventilates, depending on the user's preference to have windows or doors open. The three different scenarios are described below: 1.

2.

3.

Bedroom

Scenario 1: When inlets 1, 2 and 3 ventilate through one common outlet (1).

Scenario 2: When inlet 2 ventilates through outlet 2 Scenario 3: Bathroom inlet 3 ventilates through outlet 3.

1 3

2

Floor Plan Level 1

2 3 Duplex Section

1 Outlet Inlet

Velocity (m/s) Kitchen

Living Room

For this analysis, the focus was only on wind flow scenario No1. due to that it is the one that has to work with the most amount of wind.

We can see how the wind enters from inlets 1, 2 and 3 with a velocity of around 1.4 m/s and travels through each room towards the back and up the void of the stairs, accelerating its speed and exhausting with a velocity of nearly 2.8 m/s at the top of the outlet 1.

3.9 3.6 3.2 2.8 2.4 2 1.6 1.2 0.8 0.4 0

9.2 INDIVIDUAL STUDIES

Analysis No 1. No Box Window

Analysis No 2. Box Window

9.2.9 External Shading Design: Solar Exposure Analysis Solar exposure - Total hours One of the most important issues in the studied building is solar overexposure because of its orientation towards the southwest.

Because of this, and also because the main view is towards the same direction, an external shading device had to be designed to block unwanted solar irradiation.

Solar exposure - Warm hours (>20°C)

Analysis No 1 The first analysis was done, measuring the solar irradiation on the floor surfaces of the studied Duplex. With the resulting window sizes from the previous analysis, but with no external shading.

The results show the total hours of solar exposure on the floor of 11 KWh / m2 for the months of April to August. And a variable solar exposure when the external temperature is above 20°C. Showing the greatest value in the month of July, indicating the hottest month in the year with the most amount of hours with solar exposure.

Analysis No 2 A shading device was designed to block the unwanted solar gains into the space, this is a fixed metal frame attached to the external wall of the Duplex.

As shown on the graph in this analysis, the energy that is recorded on the floor surfaces of the duplex during the warm period (April-September) is reduced from 11 KWh / m2 to 8 KWh / m2, a significant reduction of energy in the form of solar gains which we are removing from the space, helping maintain a comfortable temperature inside throughout the year.

On the other hand, during the cold period, there was also a significant reduction of solar gains in the room.

513 KWh / m2

382 KWh / m2

311 KWh / m2

235 KWh / m2

170 KWh / m2

111 KWh / m2

398 KWh / m2

295 KWh / m2

Graph 3.

Month

KWh / m2

KWh / m2

Conclusion A combination of both systems is preferable for the Duplex to perform at its best. Each of the windows on the building will have an external metal frame fixed to the wall. The frame has a hinged mechanism which allows vertical and horizontal panels to be set in place during the warm hours of the month, to block the sun coming from the south.

These panels can be fixed to the external wall during the cold period to allow all the rays of the sun to come inside the space and help warm the room. The result can be shown in Graph 3 below.

Month

Month

9.2

INDIVIDUAL STUDIES

Analysis No 1. No Box Window

Analysis No 2. Box Window

9.2.10 External Shading Design: Indoor Daylight Analysis The same comparison with and without the box window was made but measured the impact on the indoor daylight of the Duplex.

Useful Daylight Illuminance is a metric used to evaluate the distribution and quality of daylight in the space, in the case of the No 1 Analysis (No box Window), the UDI is lower if compared to scenario No 2. This is because the frame in the box window is blocking some daylight to control better the illuminance in the space above the threshold level which is considered a good space for vital visual tasks.

Another important result to take into consideration is the annual sunlight exposure. There is a 9.3% reduction in scenario No 2, with the box window, resulting in a considerable area of the living room and kitchen having better quality, less glare and less overheating.

Conclusions On the first floor, there is a significant improvement in the quality of daylight in the kitchen and living room area. On the other hand, the second level needs further shading, especially on the double door going into the terrace, this opening will need to be resized and possibly will have to have a larger overhang shading.

* Keywords sDA - Standard Daylight Autonomy ASE - Annual Sunlight Exposure UDI - Useful Daylight Illuminance

57.9% average UDIa

81.7% sDA (300 lux)

40.9% ASE

1992 average lux

61.4% average UDIa

84.7% sDA (300 lux)

31.6% ASE

1955 average lux

9.2

Bedroom

INDIVIDUAL STUDIES

Living Room

9.2.11 Yearly DBT and energy performance

Bathroom External Temperature

Cold season The temperature during the cold season, which goes from the beginnings of October until mid April, was specified when the interior temperature of the spaces goes below 18°C. When the thermostat is set to be switched on, heating the space at a constant temperature of 18°C, the value is set according to the comfort band during winter (from 18°C-20°C). Also, it's important to state that the heating is not always on, following LETI recommendations, the thermostat follows the occupancy schedule, saving energy when the occupants are not in the space.

Temperature (°C)

Living Room 65,179.24 W Bathroom 77,837.47 W Bedroom 34,853.83 W TOTAL 177,870.54 W Floor area

35 m2

Heating Loads

5.08 kWh / m2

Heating Load (W)

According to LETI Climate Emergency Design Guide of 2021, the goal is to reach a total heating demand of 15 kWh / m2. This benchmark value could be reconsidered, because this exercise followed all the LETI recommendations for new builds, it's arguably a very well-insulated and performing building, which didn't need to have more than 15 kWh / m2 in heating demands.

This case study, with its limitations, questions the passive house benchmark for buildings oriented towards the southwest, where the heating demand is three times lower than the required.

Cold season (October- April)

Graph No 2.

Heating loads As shown in Graph 2, the heating loads are mostly during the cold months, the period in which the temperature goes below 18°C. To calculate the total heating loads, the total hourly loads in Watts were added, then they were converted to Kilowatts, and finally, the total kW was divided into the net usable floor area (35m2).

Total heating load = 5.08 kWh / m2

Warm season (April-September)

Graph No 1.

Warm season During the months of April until September, the external temperature ranges from a mean average of 9°C during the night and a mean average of 19°C during the day. Because our building is oriented towards the southwest, it receives a considerable amount of solar irradiation which heats the space. After sizing the windows and adding the shading devices during this warm period, we can say that the indoor temperature of the rooms flexes within the comfort band during this period. Creating a good balance between the maximum amount of sun that we can let into the space and the openable area of these windows creates natural wind current cooling the space and guaranteeing the user's comfort within this period.

Cold season (October- April)

LETI heating demand benchmark *LETI, Climate Emergency Design Guide, 2021

Jan

Feb

Mar

Apr

May

Jun

Jul

Ago

Sep

Oct

Nov

Dec

9.2

Bedroom

INDIVIDUAL STUDIES

Living Room

9.2.12 Yearly performance by room current climate

Bathroom External Temperature

Hottest period By separating the results by room, it was possible to find the hottest days in the year for each room.

There were 13 hours in total in the year where the temperature inside the rooms was outside the comfort band and greater than 30°C. 31.7 °C 32.9 °C 33.1 °C 32.4 °C 32.4 °C 32.2 °C 31.3 °C 30.2 °C 30.0 °C 30.1 °C 30.1 °C 30.1 °C 30.2 °C

This means that only for 2 days in the year, the outside temperature is going exceed the comfort band, and the user will have to close the windows and openings, to control the hot air from coming inside the space.

In these cases, a heavier structure would be beneficial, to add thermal mass which would absorb the exceeding heat, releasing it during the night, and therefore allowing the space to be cooler.

It's important to note that the proposed timber lightweight structure is because the existent condition of the building's structure is unknown. Therefore, to not add any unwanted stress to the structure, the former one was chosen.

-5°C

32.6°C

Temperature (°C)

29 / 06 - 14:00 hrs 29 / 06 - 15:00 hrs 29 / 06 - 16:00 hrs 29 / 06 - 17:00 hrs 29 / 06 - 18:00 hrs 29 / 06 - 19:00 hrs 29 / 06 - 20:00 hrs 29 / 06 - 21:00 hrs 09 / 07 - 15:00 hrs 09 / 07 - 16:00 hrs 09 / 07 - 17:00 hrs 09 / 07 - 18:00 hrs 09 / 07 - 19:00 hrs

32.6°C

-5°C

Cold period As it's shown on the graphs, the outside temperature from October until mid-April is below the comfort band, therefore heating is needed to achieve the desired 18°C. The coldest week is in the month of February were the outside temperature goes down to -5°C.

32.6°C

30°C

10°C

Cold - February (day 40-47)

Warm - July (day 185-192)

-5°C Jan

Feb

Mar

Apr

May

Jun

Jul

Ago

Sep

Oct

Nov

Dec

INDIVIDUAL STUDIES

9.2.13 Yearly performance by room Future climate

Bedroom

1200 CO2 (ppm)

9.2

Living Room Bathroom 600

Hottest period After simulating the same building but taking into account the future weather conditions in the year 2100, with a Representative Concentration Pathway scenario of 4.5, we can see how the overall temperature will increase, having longer and warmer summers, with a maximum of 33.6°C in the month of July.

Meaning that the number of hot days will increase, from 13 hours annually to 31 hours

External Temperature

RCP 4.5 2020

2060

Cold period On the other hand, we will also experience warmer winters, where the external temperature would not go below 0°C. This means that during the cold period of the year, we will need fewer heating loads because the number of hours the temperature will be lower than 18°C will decrease.

2100

33.6°C

0°C

Temperature (°C)

33.6°C

0°C 33.6°C

0°C Jan

Feb

Mar

Apr

May

Jun

Jul

Ago

Sep

Oct

Nov

Dec

Conclusion It's important to note that this study aims to show the deficiencies of the current regulations for new build because by following them and even going a little bit more forward with passive cooling and shading devices, the studied building would definitely have a problem in the future climate, indicating that the current regulations are insufficient.

Temperature (°C)

10

600

0

0

Day 40

Day 47

Coldest Week - Future Climate 20

700

15

676 W

10

5

0

200

Day 40

Day 47

0

30.4 °C

Hottest Week - Current Climate 30

RCP 4.5 20

CO2 (ppm)

Hottest week As indicated before, we know that in the future climate, there would be more hours that the internal conditions of the house would be outside of the comfort band. As we can see on the hottest week in the future scenario, where the maximum temperature is in the bathroom at 37°C (7°C more than in the current climate). This comparison shows the importance of working hard today to stop climate change now before the predictions come true.

1125

Heating Load (W)

Coldest week Because the conditions remain the same in the building during the current and future analysis, the same threshold of a minimum of 18°C is set to turn on the heating in the spaces of the duplex when it gets lower. That is why in both cases, we can see a constant line around 18°C, going down whenever the occupants are not at home or when the schedule is turned off. If we compare the heating loads, there is a sufficient difference between the loads needed to heat the space in the current climate than in the future climate scenario. The maximum load on the coldest day in the year is 1,215 Watts currently, and in the year 2100 the maximum heating load on the coldest day in the year would be 676 Watts.

Also, we can see that the minimum temperature goes from -6°C in the current scenario up to 0°C in the future one.

Indicating that winters are going to be milder and shorter.

Temperature (°C)

By comparing both the coldest and hottest week of the year, we can see how the overall external temperature is increasing for both periods in the future climate scenario of RCP 4.5. Also, the hottest period in the year shifted a few days in July

1215 W

20

Heating Load (W)

9.2.14 Weekly performance comparison between current and future climate

Coldest Week - Current Climate

Temperature (°C)

INDIVIDUAL STUDIES

10

Day 185

37.0 °C

Day 192

600

Hottest Week - Future Climate 2020

2060

2100

30

Temperature (°C)

9.2

Bedroom

20

Living Room Bathroom External Temperature

10

Day 201

Day 208

9.2

INDIVIDUAL STUDIES

Summer Facade

A

Winter Facade

2

2

1

1

2

2

1

1

9.2.15 Duplex Conclusions After sizing first the inlets and outlets to ensure optimal ventilation and then sizing the windows to have the largest windows possible, the study showed that for the living room area, the best type of window to gain more heat during winter is the larger type window (1.2 m x 2.2m). On the other hand, for the bedroom, the analysis showed that is more convenient to have a smaller window (1m x 1.4m) because it will allow the space to be cooler during summer and warmer during winter.

The box window design helps the performance of the space by blocking the sun during the summer hours, especially during the warm hours from 10 am until 4 pm. The hinge mechanism allows this design to be flexible in order to allow the rays of the sun to enter through the space and heat it passively.

July

December

As illustrated in sections 1 and 2, each of the spaces inside the duplex serves a specific purpose. They are designed to cope with the user's needs while having quality daylight and ventilation. We know that each activity results in internal gains, therefore, an individual ventilation proposal was made to be certain the internal heat loads, for example in the kitchen in Section 2, can be properly taken out through a sky window that ventilates.

10 hrs

A

10 hrs

13 hrs

We can conclude that after following the passive house LETI recommendations, the building in terms of energy performs better than LETI benchmark. But on the other hand, because of its orientation towards the southwest, there are some hours during the summer period when the dry bulb temperature rises higher than the comfort band even with all the insulation requirements and triple glazing. we can question the benchmark for this climate, especially if we consider that the future climate perspective will change drastically the conditions that we know.

13 hrs 15 hrs

17 hrs

Terrace

Bath

Access and stair shaft

Living Room Living Room Kitchen

Section A

Section 1

Section 2

10. RELATIONSHIP WITH CONTEXT 10.1. Microclimate

Image 1. Air temp Roof Level

Image 5. Wind speed duplex

20.2°C

.5 m/s .9 m/s 1.4 m/s 1.8 m/s 2.3 m/s 2.8 m/s 3.2 m/s 3.7 m/s

21.7C

To study the microclimate the new project proposal was generating, a simulation using Envimet was made.

The objective was to first analyze the comfort conditions on the roof extension. The second one is to make sure we wouldn't be generating any problems for the neighbours in the adjacent context.

22.0°C 22.9°C 23.5°C

Image 2. Air temperature Rooftop Extension

Roof extension In image 2, we can see the air temperature at the corridor level on the northeast ranges between 20°C and 21°C, temperature well within the comfort band.

This is also the case if we analyse the air temperature resulting on the rooftops of the duplex in Image 3, where the users can enjoy of the private terraces.

On the other hand, if we analyze the airspeed at these two points we can see how in images 5 and 13, there is a wind velocity of 0.5 m/s up to 1.2m/s. We can say that the wind velocity resulting in these important corridor spaces is comfortable and can allow people to travel safely, even when it is at the exterior and on a high level of 13 meters above the ground.

Image 6. Wind speed co-living 20°C

.5 m/s .9 m/s 1.4 m/s 1.8 m/s 2.3 m/s 2.8 m/s 3.2 m/s 3.7 m/s

20.4C 20.8°C 21.2°C 21.6°C

Image 7. Wind Speed at 13 m

Image 3. Air temperature Rooftop Duplex

.7 m/s 1.2 m/s 1.7 m/s 2.21 m/s 2.6 m/s 3.1 m/s 3.6 m/s 4.0 m/s

20°C 20.4C 20.8°C 21.2°C

Context As we can see from image 4. The air temperature in the opposite building keeps its temperature constant, around 19°C. Also, we can see from image 8, it receives a good flow of fresh air in its main facade, ranging from 2m/s to 5m/s on the facade.

21.6°C

Image 8. Wind speed in facade m/s

Image 4. Air temperature in facade

19°C 20.7°C 21.6°C 22.4°C 23.3°C

1 m/s 2 m/s 3 m/s 4 m/s 5 m/s 6 m/s 7 m/s 8 m/s

11.

CONCLUSIONS 11.2. VIEWS OF PROJECT To objective of this design project since the beginning was to be mindful of the surrounding context and to take people's needs and people's comfort as our main priority. After tackling the challenge of having a refurbishment project on the upper floors of the existing building, and then proposing an extension at the roof level, we can say that in terms of comfort, the user of these spaces will have an improvement in terms of quality of daylight, natural ventilation, connectivity and accessibility.

With a sense of community, we are proposing a small improvement to the Church Street block that took into consideration not only its site's current climate but looked at the future one too, making sure that we know the weaknesses and strengths of what we are proposing.

BIRD’S EYE VIEW FROM COURTYARD

FRONT ELEVATION

12. REFERENCES

Guides LETI Climate Emergency Design Guide. How new buildings in the UK climate change targets. January 2020 edition.

LETI Climate Emergency Retrofit Guide. How existing homes can be adapted to meet UK climate targets. October 2021 edition.

ASHRAE Standard 90.1-2019.

Websites Climate of London. Encyclopedia Britannica. Encyclopædia Britannica, inc. Available at: https://www.britannica.com/place/London/Climate (Accessed: April 5, 2023).

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Software ● ● ● ● ● ● ●

Rhinoceros Meteonorm Optivent 2.1 Climate Studio Envimet CFD 2023 EDSL TAS