Urban agriculture of the future: an overview of sustainability aspects of food production in and on buildings

Innovative forms of green urban architecture aim to combine food, production, and design to produce food on a larger scale in and on buildings in urban areas. It includes rooftop gardens, rooftop greenhouses, indoor farms, and other building-related forms (defined as "ZFarming"). This study uses the framework of sustainability to understand the role of ZFarming in future urban food production and to review the major benefits and limitations. The results are based on an analysis of 96 documents published in accessible international resources. The analysis shows that ZFarming has multiple functions and produces a range of non-food and non-market goods that may have positive impacts on the urban setting. It promises environmental benefits resulting from the saving and recycling of resources and reduced food miles. Social advantages include improving community food security, the provision of educational facilities, linking consumers to food production, and serving as a design inspiration. In economic terms it provides potential public benefits and commodity outputs. However, managing ZFarming faces several challenges. For some applications, the required technologies are known but have not been used or combined in that way before; others will need entirely new materials or cultivation techniques. Further critical aspects are the problem of high investment costs, exclusionary effects, and a lack of acceptance. In conclusion, ZFarming is seen as an outside-the-box solution which has some potential in generating win-win scenarios in cities. Nevertheless, ZFarming practices are not in and of themselves sustainable and need to be managed properly.