When architect Thomas Chung Wang-leung wanted to present an alternative use for yet another Hong Kong institution destined for urban renewal - in this case, the 160-year-old Graham Street wet market in Central - he did so not in Hong Kong, but across the border in Shenzhen. Specifically, it was the former Guangdong Glass Factory in Shekou that provided the model, courtesy of the invitation-only Shenzhen Hong Kong Bi-City Biennale of Urbanism\\Architecture held there in 2013. Chung's vision for Value Farm - a living, breathing, productive farm that engaged the community for months on end and provided food for their tables - recently won gold in the Hong Kong Institute of Architects Cross-Strait Architectural Design Awards 2015. Chung is an associate professor at the school of architecture at Chinese University. "When [curator] Ole Bouman invited me to do something to showcase Hong Kong, we thought urban farming might be a little unexpected. Compared to the [usual scenes of] Victoria Harbour, high-rises, and glamour, this might be something new Hong Kong could offer to the world," Chung said. The project's design inspiration came partly from an emerging global trend whereby city dwellers are reconnecting with the hands-on experience of growing crops as a means of offering a more secure, accessible food supply. "Besides pointing to an attitude and lifestyle change, it's about experimenting with what can be done with hitherto untapped land resources, such as on rooftops, terraces and balconies, inside parks and under flyovers," Chung said. The "lively urban vernacular of Hong Kong's Central district" - in particular the 170 year-old Graham Street wet market precinct, "whose low-rise fabric embodies the city's fine-grain metamorphosis" - was the second source of inspiration. "This area is currently facing wholesale redevelopment and with it the impending eradication of the neighbourhood's self-evolving meshwork of spatio-cultural practices," according to Chung. "Value Farm speculates turning rooftops of an entire demolished wet market block into farming terrain. Nature is excavated anew from Hong Kong's urban past." The team did not just plot a garden, but designed it in different layers reminiscent of Hong Kong rooftops - a multi-layered arrangement of platforms, pavilions and footpaths interspersed with beds of seasonal, edible crops. Brick enclosures at different heights reference Graham Street's demolished rooftops, with original stair cores from the same precinct converted into open pavilions to accommodate community activities. Attributes from the Shenzhen site further reveal the "value of the land". Features such as old factory walls were given new life as a focal point of the main entrance. A wall and a pond dug into a natural underground water source turn an "obsolete ruin" into an integral part of the project's productive landscape, which also irrigates the crops via a sprinkler system. Trees were planted to reduce the environmental impact, and a once-withering old tree rejuvenated. A circular bench was made from recycled timber planks from elsewhere on site, with a leftover circular metal frame for its legs. It enveloped a large tree and provided a shady spot in summer to complement the productive farming plots. In this way, Chung said, the project aligned with the project theme of producing something new out of old buildings. Value Farm "reworks the site to produce nature, using farming to revive the land's fecundity", Chung added. Hong Kong farmers contributed their knowledge, engaging the Shenzhen community to cultivate, harvest and ultimately share the crops grown over the four-month biennale period - from early December 2013 to late February 2014. The crops were chosen to demonstrate the farm-to-table concept of healthy eating, allowing urbanites to appreciate the direct relationship between land, food and people. At the same time, they represented a pleasing artistic and cultural palette: local winter wheat and flaxseed; imported lettuce, endive and radicchio; Swiss chard, zucchini, bell pepper and tomato; particular versions of carrot, beetroot and radish; and a range of common cultivars including cabbage, cauliflower, broccoli and Chinese kale. They complemented each other visually to enrich the overall landscape. Though the crops are no longer growing, Value Farm's infrastructure remains in place. The whole site is undergoing renewal, and it is Chung's hope that the developer, the state-owned China Merchants Group, will choose to keep the farm going. It wasn't so much about feeding the masses, Chung maintains, but about showing the world what architecture can bring to underutilised urban land, inspired by "Hong Kong rooftops in their different forms".