The increasing densification of urban populations, rising costs of living, and the acceleration of a changing climate has driven a social awareness for environmental issues, and the need for sustainable lifestyles. Conventional food production is confronted with the loss of arable land, diminishing fresh water supplies, and disruptions to the global supply chain. The need to strengthen food security has driven cities to incorporate agricultural production into their urban landscape.

This project re-examines sustainable urban agriculture by first understanding the importance of food security in Singapore, where food is a key part of its cultural identity, and its geopolitical context has enabled it to become a hotbed for food production innovation, supported by its goal to produce 30% of its nutritional needs by 2030.

Current agricultural approaches are focused on high productivity using smart technologies, such as climate-controlled environments and artificial lighting. While useful in supplying markets with fresh produce, such methods of designing a “black box farm” intensifies the need for energy-hungry systems to sustain growing cities. It also disconnects communities from intimate relationships between people and their food, a key opportunity in fostering food conscious communities. By looking at the limitations of existing solutions, fundamental ideas behind urban agriculture will be challenged. Stakeholders must recognise the premise of long-term sustainable agriculture through intelligently designed spaces and phased expansion, a proposition which is becoming increasingly urgent in today’s climate.

Instead of seeking methods that maximise agricultural output at all costs, a new architectural paradigm focused on low-energy processes and circular systems is proposed. Architecture can complement agriculture in looking beyond Singapore’s 2030 target. In designing for urban food security, integrated designs can go beyond feeding future generations and cultivate ties between communities and their food.

The rise of car-lite policies, and the 45-minute city, 20-minute town model, combined with recent work-from-home policies due to the global pandemic, reduces our reliance on private vehicles. Fewer cars cuts down the demand on road infrastructure such as parking spaces, which can be repurposed for other needs.

To take advantage of these policies, the opportunity presents itself in repurposing car parks into urban agriculture spaces within Singapore’s public housing neighbourhoods, or HDB estates, where 80% of the population reside. To achieve the “30 by 30” goal, up to 51 multi-storey car parks could be repurposed into commercial farming spaces. Considering that there are over 900 of these car parks around Singapore, 51 is a small fraction. So could we go further? The 2030 target is only a touchpoint, and more can be done in the following years to bolster Singapore’s food security.

A computational analysis was done on 932 car park sites to quickly narrow down the selection. A series of quantitative and qualitative criteria, such as car park orientation and footprint typicalness, was used to parametrically score all the sites.

Agropolis is a prototype for a urban lifestyle, bringing intensive agriculture into urban neighbourhoods. Repurposing Singapore's public housing multi-storey car parks by converting the rooftop space into productive commercial urban farms, but also providing community spaces within the car park structure, such as cafes, community gardens, workshop spaces, farmer's market and childcare centres. Agropolis is connected directly to surrounding residential blocks via elevated linkways, providing convenient and safe pedestrian routes away from vehicular traffic. These community hubs will also be knowledge hubs, for hobby farmers and industry professionals to share their skills and passion for plants.

These systems are part of a wider toolkit, aimed at redeveloping multi-storey car parks around Singapore into neighbourhood food hubs. The toolkit ensures that designs are not repetitive, while also minimizing redesigns. While Agropolis speculates the possibility of neighbourhood food hubs, the architectural and engineering technologies already largely exist. The systems proposed are not just applicable to Singapore, but to many other cities around the world.

The car park structure, which is reinforced concrete, is reused almost in its entirety, reducing carbon impact. Additional concrete columns extend through the structure, to take the additional load from the rooftop urban farms. These farms are constructed with pre-fabricated steel modules, constructed off-site to ensure quality manufacturing and reduce on-site labour. The farm modules consist of trays which rotate around to ensure crops receive equal sunlight, powered by gravity and water, which is then used in the aquaponics systems.

The open facade allows for natural ventilation, reducing energy consumption from mechanical ventilation and artificial lighting. Operable photovoltaic roof panels can open in the day to allow natural light into the farm, or close to shade crops from excess sunlight, and during wet weather to harvest rainwater.

To ensure a successful transition into sustainable community lifestyles, a three phased approach for Agropolis is proposed. The first phase sees the addition of the commercial farm modules, replacing the upper deck with commercial and public programmes. Food-oriented amenities, along with auxiliary farm spaces are located below the rooftop level, while the ground floor is use for F&B spaces. This forms the main hub, a seed planted within the community.

The second phase integrates the food hub with neighbouring blocks, by introducing community gardens and steel-truss elevated linkways. Car parking is also gradually reduced.

The last phase looks at how households can take up their own urban agriculture practices, by encouraging home gardening. By allocating just 2 square meters of growing space per unit, every HDB household could supplement the 30% commercial production to become fully, 100% self sufficient.

Circular systems ensure that waste is not wasted. This is seen through the water, and food production cycle, where waste is a resource. Harvested rainwater is used to water crops, which is then cleaned via the aquaponics systems, before being distributed within the building for non-potable uses, such as flushing toilets and cooling. Food waste is another often overlooked component, which can be collected in bulk from the surrounding residential neighbourhoods to be composted, for mushroom cultivation and fertilizer.