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potong pasir loop; a semester renewed with hope and pastel hues, with the courage and confidence to further push myself to achieve much more - i’m glad that i was able to create a c4 that i could be proud of. nonetheless, this c4 aimed to combine different idealogies into one singular bridge-form, where the different hierachy levels each represented advocacy for climate change. my research on urban farming led me to further understand systems of aquaponics and shaped my architecture greatly. hence, function leading to form. overall, a great semester of development and learning through my studio mates and prof swinal, looking forward to the next!
Lim Qian Ping Annabelle A0157481Y
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FOREWORD
The studio adopted a research informed approach for the design of the Centre for Cities and Climate Change (C4); this was primarily afforded by the multifaceted analysis of the chosen site along the 10 km stretch of Kallang River, and the tailoring of the generic brief to articulate more compelling narratives for the project. Critical understanding of the natural and built characteristics of the site and the surrounding urban context, including its socioeconomic, environmental, and cultural conditions, formed a strong basis for the distinctive site choices students made, from those along the river to those bridging the river, on and along the pier and even on the underside of a bridge and so forth. Importantly, the mantra ‘Think global, act local’, served well in the framing of the key drivers for the projects as students considered the larger climate issues whilst concurrently defining specific climate change concerns that were personally meaningful and pertinent to Singapore, and those that were emergent from the chosen site and its local environs. They importantly formed the basis for the discussion of the larger role of architecture, one that would support ground up, community led actions and educational programs, and engender social and behavioural change, and in doing so, empower the local and the wider community. Engagement with the identified issues, whether it be light pollution, urban flooding, unsustainable water use, pollution and waste, urban farming, unsustainable practices related to cremation and burials, and recycling and upcycling, meant that the resultant architecture was very process driven and there were many interpretations of the C4. This was articulated in the incumbent curriculum, and the teaching and learning pedagogies that became the embodiment of the projects and informed the ensuing programmatic innovation, and the orchestration of certain experiences and precise journeys, that were enhanced by the distinctive water-based site contexts and the immediacy they offered. Beyond the congruent spatial explorations, great consideration was also placed on the environmental approach to design and it importantly informed the form, orientation, massing, fenestration and envelope design, materiality, structure, and the spatial and overall tectonic qualities of the projects. Finally, the student projects sought to draw people closer to water, challenging the current conditions of restricted public access and the notion that the city has seemingly turned its back to the Kallang River. The architectural propositions, therefore, created intimacy with the river, and in doing so, crafted evocative, immersive and authentic learning experiences on the various aspects of sustainable urban living in the context of a modest scale building, termed the C4. Dr Samant Swinal Ravindranath, Design Tutor National University of Singapore , Department of Architecture April 2018
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1: Engaging Environment: C4 at Kallang River POTONG PASIR LOOP
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1. Programme/Project
The brief is to select a site along the Kallang River and design a Centre for Cities and Climate Change (C4). The client for the Centre is a Singapore-based non-governmental organisation (NGO) named Beyond Sustainability and Liveability (or BSL).
The client and its mission
Founded and funded by a former venture capitalist and a former CEO of a Silicon-Valley-based technology company, who both felt guilty about the environment impacts of their former careers. Wanting to compensate for the environmental damage and offset the carbon emissions they (and their companies) have directly or indirectly contributed to, they set up BSL and provided it with a large endowment. The annual operation cost of BSL is fully covered by interests and investment returns generated from its endowment, ensuring its long-term viability and making it much more autonomous than the NGOs that depend on public funding. Its financial independence enables it to put forward a more radical socio-environmental agenda than that of most environmental NGOs that tend to advance slightly-ahead-of-the-curve agendas that nudge society to be slightly less bad environmentally without fundamentally challenging the root causes of our current unsustainability and rapid descent into an impending climate catastrophe. BSL’s mission is thus to go beyond sustainability, the business-more-or-less-as-usual approach to dealing with climate change. BSL is especially critical of liveability and its attendant focus on quality-of-life issues. BSL sees liveability as obfuscating the real challenge behind climate change mitigation: overconsumption. Instead of relying on technological fixes with token social adjustments that underpinned discourses of sustainability and liveability, BSL advocates fundamental socio-cultural transformations towards greater socio-environmental awareness, leading to collective actions towards reducing our carbon and ecological footprints.
Site and Programme
As part of the fulfilment of its mission, BSL plans to set up a Centre for Cities and Climate Change (C4) to promote public understanding of urban environment and climate change – both in terms of the environmental impacts of cities and urban lives that contribute to climate change, and the impacts of climate instability on cities and urban lives – in order to facilitate collective action on climate change mitigation and a low carbon future. The government has granted the NGO the choice of a plot of land along the Kallang River to build C4. The overall task for you in this semester is to design C4. This task itself is broken down in three interconnected components: A. Urban environmental analysis of the site (3 weeks) B. Architectural design (6 weeks) C. Detailed envelope design (3 weeks) 8
01. centre for cities and climate change (C4); P O T O N G P A S I R L O O P,
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S I T E A N A LY S I S ;
exploring possibilities of a location within the heart of the St. Andrew’s Schools
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SUN SHADING AND GREENERY
Shading is generally fine about the park connector walkways as they are lined by the trees that are planted mostly on the West bank of the river and along the roads. By mapping the building heights and looking at the site shadows created, we can see that the banks of the river are mostly shaded by the taller HDBs on the east side of the banks. On the west side of the bank, the school is a low-storey building and hence, the shading is mostly done by the trees. It should be noted that the newly manicured gardens along the park connector on the east side of the bank lack general shading near the edge of the river as little trees are planted and more “gabion� like structures for storm water management are planted instead. There are also 2 main big open fields north of the school which are used for future development, these are not shaded at all.
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H U M I D I T Y, G R E E N E RY AN D PAT H WAY S With a psychrometer, I have investigated the humidity on both sides of the bank, with my findings mostly showing me that the wet-bulb and dry-bulb temperatures account for a higher relative humidity on the west side of the bank. This is mostly due to the denser canopy on the west side of the bank, where bigger and older trees are found thus a higher rate of evapotranspiration . It is also important to note that as this is a tropical climate, this area does receive frequent rain especially during the monsoon seasons.
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WINDFLOW The area experiences a good amount of wind flow throughout the day, with a wind tunnel created along the river channel due to the buildings surrounding it. The wind flows from north to south and concentrates itself along the river, where it flows the fastest due to no obstruction. Hence, the C4 will make use of the prevalent winds by enabling natural ventilation where it is at the normal to the wind direction and ensure that it allows wind to flow through it instead of around it by having the building height be lower than the surrounding buildings.
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CONCLUSION
It can then be concluded that the resultant human activity that is concentrated on the west bank of the river would largely be due to the better shading it offers. Hence, the public is seen to be carrying out physical activities such as running and cycling more on the west as it would be more comfortable to do so in the day. The picturesque views of the east side of the bank also provide an enjoyable view for those doing activities on the west side. It is only during the evening and night time that we see more people using the facilities on the east side of the river, where shade does not play a big factor due to time of day. The C4 would then hope to better bridge this connection between both banks, by providing a place of shade and comfortability for people to gather and learn about climate change.
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C L I M AT E C H A N G E I S S U E ;
through our large carbon footprint, due to more then 90% of our food being imported from overseas, we live excessively due to affluence that we rack up an increasing amount of food waste. NEA tries to combat this through educating our youth about this problem while urban farming efforts continously emerge as our society recognizes this issue.
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A Q U A P O N I C S & S U B S I S T E N C E FA R M I N G I N S T . A N D R E W ’ S S C H O O L S ;
a relatively new idea, aquaponics combines hydroponics and aquaculture to create a closed loop system that is self-sustaining - a viable idea that brings us back to the history of Potong Pasir, where subsistence farming was commonly practiced. hence, this programme aims to teach the students about the climate change issue through hands on learning within the cycle of aquaponics.
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I T E R AT I O N O N E ;
my first iteration sought to create a form that suited my programme, and also of the context around it. there were alot of bridges linking the West bank to the East bank, where the latter had an already developed ABCs pavilion and gardens that were underused. thus, i sought to bring back more activity to the east bank, while containing the programme within the boundaries of the St.Andrew’s schools.
(left: architectural massings of approximate 1100m2, right: iteration one design) 18
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I T E R AT I O N T WO ;
the second iteration sought to further push the cranked form through addition of corridors and balconies so as to continue circulation flow within the architecture itself. the internal organization was also worked through further and different modes of green/farming were explored.
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I T E R AT I O N T H R E E ;
for the third iteration, I aimed to create a more consistent architectural language that showed throughout the entire C4, also looking at the allocation of spaces and how to make the roof more lightweight. the structure also aimed to be more like a bridge and less reliant on traditional building structures.
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OPEN EVENT SPACE
CAFE
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OPEN GALLERY AREA CROPS FARM MAINTENANCE
FARMER’S POP UP MARKET
FLOOR PLAN 0M TO 2M
CLASSROOM ENTRANCE AREA
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E L E VAT I O N 1 - W E S T
E L E VAT I O N 2 - S O U T H
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SECTION A
SECTION D
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SECTION E
SECTIONB
SECTION C
final C4;
P O T O N G
P A S I R
L O O P
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P O T O N G
P A S I R
L O O P
is a multi-faceted urban intervention nestled in the heart of the St. Andrew’s Schools that brings awareness through hands-on education. This Centre for Cities and Climate Change (C4) aims to tackle the carbon footprint of Singapore’s food imports and wastage by introducing a newer form of urban farming, ‘Aquaponics’. Consisting of three levels that showcase the different hierarchy in space – a ‘floating’ farm, a main gallery space and a bridge, it aligns itself accordingly to the natural wind and river flow of the site, making use of the site context and its agricultural history to the best of its ability. The C4 is mostly naturally ventilated, requires minimal energy consumption and provides a closed-loop agricultural system that results in little to no waste produced whilst contributing to the food subsistence of the area. Circulation in the building also runs in tandem with the idea of a closed-loop, where visitors and users of the building tend to always be connected within this loop, with a central node being found in the main gallery space. The architecture contributes to the C4’s ethos of creating an urban utopia, where people are reconnected with the idea of consumption and production, hence being better equipped to understand the environmental and social values of sustainable living through a closed-loop system.
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OUR ETHOS;
T O C R E AT E A N URBAN EUTOPIA to tackle food wastage and reduce our carbon footprint by bridging a connection from our humble beginnings to provide sustainable awareness for the future
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SITE PLAN; C4 Gross Floor Area: 2220 m2 (Naturally Ventilated: 1548 m2) C4 Building Footprint area: 5238 m2
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The C4 is in the heart of Potong Pasir, sandwiched in between St. Andrew’s Junior College, Junior School and Secondary School. It is also surrounded by the Potong Pasir HDB estates, CTE and PIE expressways. The main reason why this site was chosen was due to the presence of the three schools in the periphery of the area, which is unique due to the different educational levels of each of the schools.
Keeping the site context and curriculum in mind, there are a few main points that I have concentrated on. These include: Having adequate natural ventilation, Having sufficient sun and rain shading, Managing the Aquaponics urban farming system, Managing the Green Roof. These points capture the ideas of a site efficient yet ecologically friendly piece of architecture, the Potong Pasir Loop, minimizing the carbon footprint of the daily use of the building yet allowing it to run proficiently. 33
PLANS The shape of the building is cranked so that every circulation path would bring you back into this closed loop. It is in correlation to the aquaponics programme and situates itself in line with the wind and river flow direction. with starting, mid and end nodes for human circulation, the visitors of the c4 will gather around these nodes and spill out into the activity spaces. This circulation path also brings us around a situated tour that is in line with the aquaponics closed-loop system, enabling one to learn both visually and also interact with the system itself. It has spaces for both public and school use, for the intention of making it a school programme.
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H AV I N G A D E Q U AT E N AT U R A L V E N T I L AT I O N
The C4 was made sure to be placed perpendicularly to the wind flow through the river channel to maximise the chance of natural ventilation through the wind tunnel as seen in the Flow diagrams. Also, I made sure to not build too much vertically and instead use the site more horizontally to minimize obstruction of wind flow, thus keeping heights to a maximum of 5m from the ground plane. This also allowed me to keep the energy consumption of the building to a minimum, where mechanical ventilation was only used when the wind flow was parallel to it and unable to ventilate the space well enough.
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H AV I N G A D E Q U AT E N AT U R A L V E N T I L AT I O N
Considering the N-S wind flow, the main gallery space as seen in this section is designed to be as open as possible. There is minimal use of walls to ensure no obstruction in flow – with only the indoor part of the cafÊ being enclosed in a glazed glass wall. This main gallery space is structured to be like a bridge, where Howe trusses and concrete columns are the main structural components, needing no support from walls unlike a regular building. Also, this works in hand with my circulation paths that are in closed-loops as well. As seen in the level 2 floor plan, the midpoint offers a central node, where people will commonly gather about. Thus, by making use of the natural wind tunnel effect, we are then able to better ventilate this space so when it is most populated (compared to other parts of the building), allowing the users to have better comfortability. The hypothesis is made valid after testing my design in the Flow application, where it showed that the wind tunnel through the river still exists even after the C4 is built. This is probably attributed to the low height of the C4 itself, where heights mostly vary from 2.5m to 5m, in comparison to the 12m to 60m buildings surrounding it.
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P R O P O S E D S TA C K V E N T I L AT I O N
Due to the middle portion of the gallery space having a higher ceiling height thus exposing a gap on the roof surface, this portion was debated to be used as a form of stack ventilation, where the double roofing could provide a better cooling effect. However, the lack of space and height for sufficient overhang meant that rain could easily permeate the building and hence renders it useless as a place of shade. Thus, it was sufficient that the space could be cross ventilated naturally as it was mostly open, and that stack ventilation would not be needed in this case.
M E C H A N I C A L V E N T I L AT I O N Due to the design of the C4, the areas more parallel to wind flow tend to be unable to receive as much cross ventilation as other parts which are more perpendicular. These areas include the maintenance rooms, classrooms, meeting spaces and the storage rooms located on level 2 and level 1. Thus, open spaces such as the open gallery space meant for roadshows need to be aided with mechanical ventilation such as fans more than other areas like the main gallery space as talked about previously. Furthermore, the need for mechanical ventilation such as air conditioning is a must especially in the maintenance and storage rooms due to the precise scientific nature of the Aquaponics system. This includes being able to keep the Black solider fly and its larvae in cool temperatures to the storage of harvested Jade Perch Fish in colder temperatures so that they are safe for consumption later. 37
H AV I N G S U F F I C I E N T S U N A N D R A I N S H A D I N G The site surrounding the C4 generally provides some form of shading for the C4 itself as seen in the shadow study for 21st June, 8am. However, the main form of shade for the C4 itself would be due to the general overhang of 2m included on both sides throughout the building. This gives sufficient rain shading especially in a tropical environment. However, this overhang may cause the building to be quite dimly lit especially in the large span of the main gallery space.
L I G H T S H E LV E S With a higher ceiling height for the main gallery space to show hierarchy of space, the gap in between the higher floor plate and lower floor plate is evidently not covered up as this brings in light into the space. Whilst giving it poetic properties of filtered light through this light shelf, it also helps to illuminate the space, minimising the need for artificial lighting. The glazed glass faรงade of the light shelf is angled inwards towards the inner lower floor plate (the green roof) with an overhang (topmost floor plate). This helps to overcome the overheating of the glazing by minimizing the surface area that is exposed to direct sunlight.
ARTIFICIAL LIGHTING Artificial lighting is mostly used sparingly in the mechanically ventilated rooms where windows already help to bring in natural sunlight. It is also used when certain parts of the spinach farm are unable to get sufficient light due to the shading provided by the building above it.
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A Q UAP O N I C S U R BAN FAR M I N G S Y S T E M Aquaponics is a combination of aquaculture, which is the growing of fish in this case, and hydroponics, which is growing plants without soil (North 2016). This system uses both aquaculture and hydroponics in symbiotic combination, in which plants are fertilized by the fish’s waste and in return the fish benefits from the vegetables in some sort of way. In this case, the spinach harvested is used to feed humans which in produce food waste. This food waste will then be used to feed the Black Solider fly which in turn reproduce to many larvae that eventually become food (pupae) for the Jade Perch fish. Extra food waste or fertilizer secreted by the pupae will then be able to processed through the “Eco-Wiz” technology that uses microbes to break down food waste into grey water that can be used for cleaning or simply act as fertilizers for the media filled beds that is another type of farming found in planters on the roof of the C4 or on the steps leading down to the farming area. This closed-loop farming system runs on a circular economy approach, where instead of importing fish and vegetables from other countries, we have the capacity to provide for the system from head to toe within our community. This makes it a great model that can be replicated in many communities with sufficient space to do so as not only does it represent itself as a hands-on approach to learning about food wastage through this C4 experience, it also provides fish and spinach that can be a source of food for the society. Benefits of aquaponics include 450% less carbon emissions compared to a normal farm, where 40% of the world’s carbon emissions are contributed by agriculture (FAO 2014). It also has a 142% increase in yield compared to regular farming (C.Love, et al. 2015), where no chemical nutrients are needed unlike in hydroponics. This in turn allows the water to be recirculated in a closed system, where there is no need to change the water due to built-up nutrients unlike hydroponics as well.
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SPECIALISED CLOSED LOOP AQUAPONICS SYSTEM IN THE C4 Modelled after a case study from Citizen Farming, a successful aquaponics system in Singapore, the closed loop mechanism consists of 5 main parts. Which is the cultivation of the Jade Perch fish, Spinach, and Black Soldier Fly, Harvest of both and the Treatment of food waste. There are specific reasons why each of the species are chosen – mostly due to their nature of easier cultivation. The Black Soldier Fly, is a versatile insect that can eat almost anything yet produce a larvae that is able to grow into pupae of a similar nutritional profile as other animal feed for the fish (Newton, Sheppard and Burtle 2013). The Jade Perch Fish on the other hand can reach maturity at 800g in 7 months from an advanced fingerling size, which is fast for a species of tilapia. Maximum farming densities are about 40-50kg per m3 (Queesnland Government 2016), which make it viable in my scale. The type of spinach chosen would be the Baby Leaf Spinach, which yields 1.9-2.1kg/m2 in about 52 days (Morgan 2017). Being able to harvest about 180g of leaves from a total weight of 400g per spinach, the yield is substantial for the amount needed in this scale. Spinach is also an easy to grow crop when situated in aquaponics and provides good nutritional benefits. The system is then placed in relation to the closed loop where the fish rearing tank management filters the sediments from the water with the nutrient waste to bring it through pipes lining the bottom of the walkways. These pipes are then linked to the tanks with the spinach crops in it that rest on trays that float on the surface of the water. The reason why the fish farm is placed before the spinach farm is to facilitate the better movement of water through the pipes that flow the same way as the river direction (N to S). Also, it is important to note that the water used in this system is taken from the river but is held in a closed system to minimise nutrient leakage to the original water basin.
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S U B S I S T E N C E FAR M I N G E F F O R T S Bringing back the idea of past subsistence farming in the area, I’ve calculated the amount of space needed to grow just enough spinach to feed the entire school community salad for a day. With a total school population of approximate 4,700 and the understanding that one must have 2 cups of raw leafy vegetables for lunch per serving (Petre 2017), I have come to the conclusion that we would need 260m2 of farm space that will account for the 3130 spinaches required every harvest cycle of 52 days.
GREEN ROOF The main purpose of having a green roof is for Water conservation, to reduce Storm water runoff and to try and mitigate the Urban heat island effect. A modular green roof system modelled after LiveRoof enables a built-in place system without having to face extensive maturation. The green roof mainly uses pre-vegetated carpet that requires less maintenance. Irrigation can be done mechanically or through storm water – where the soil in the green roof system absorbs and filters the excess rain water, reducing runoff by 90% annually (LiveRoof Hybrid Green Roofs 2018). This also helps with the already on-site storm water management such as the canal and gabions to lessen erosion of the river bank. Drainage is also done through a drainage system in the green roof itself and by having the roof slant at certain gradients – this helps to reduce stagnant water flow and allows the excess water to filter off easier. The urban heat island effect can be mitigated to an extent through the vegetation on the green roof that helps to cool the air and slow the air movement for air pollutants to settle out and detoxify. 42
MAIN STRUCTURAL SYSTEMS
Foundation : Foundation pad is piled deep into the river bed due to the water-logged soil conditions. Trusses : The two floor plates of the main gallery space are sandwiched and held up by the Howe Trusses. The girders support the double roof height too. “V� Columns for Bridge Support: These thick concrete columns help to prop up the main part of the bridge, whilst the other ends of the structure rest on the bank.
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H I E R A C H Y O F S PA C E S Potong Pasir Loop consists of 3 main layers - (from top to bottom) : Level 3 - Roof Garden and Bridge, accessible by the general public Level 2 - Main Gallery Space, amentities and maintenance space Level 1 - Farming Areas, fish and crops The C4 accomodates for both the public and the private, allowing it to function as a bridge, a gallery space and a farm all at once. Hierachy in spaces like the main gallery space on level 2 is shown by the double roof height, bringing in extra light and importance to the main circulation node. More private spaces like maintenance spaces for the fish are put at the ends, where there is lesser human circulation , for more privacy for the students and workers that are carrying out tasks there.
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CONCLUSION
All in all, Potong Pasir Loop is a C4 that focuses mainly on the program of Aquaponics, where the ultimate lesson in mind is to educate the students and the public about how food wastage and imports account for a large carbon footprint that results in the imminent climate change. The site choice was carefully chosen and the C4 was orientated in a way to maximise the ability to best make use of the tropical elements such as wind, water and sun direction. One of the main ideas the C4 wishes to portray would be being a piece of architecture with a minimal energy consumption, which is self-sustainable in terms of program and encourages people to live ecologically, going against the idea of excessiveness in our society these days. Through a smaller scale, the efforts of the C4 to reduce its carbon footprint in the world aligns itself to tackling many upcoming problems Singapore faces in the current era. This is in hopes that we would one day be able to live much sustainably as a nation, with a similar model of Aquaponics being reproduced in many other places.
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SECTIONAL MODEL 1:50 46
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P O T O N G PA S I R L O O P M O D E L 1 : 2 0 0
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