Food Producing Façades Key to A Sustainable Future

The built environment uses significant and increasing amounts of energy, more than 1000 times the energy density per unit area of the natural environment, contributing to Urban Heat Island effect. Simultaneously, population growth and urban development have outpaced food production globally. In response, there has been a growing trend to further develop the ancient tradition of incorporating plants into the built environment via green roofs, green façades, urban agriculture and other green infrastructure. Research is limited, however, into the application of growing food producing plants on a living façade to improve total building performance. This dissertation investigates the role of integrating food producing plants into a living façade to positively impact four outcomes: food production, thermal performance, air quality and rain water management, in a temperate climate. The design, construction, operation and end-of-life disassembly and recycling of a food producing living façade on the south and west of the Robert L. Preger Intelligent Workplace at Carnegie Mellon University successfully demonstrates the critical value of living façades for this climate. A maximum average production of 2.64 kilograms of produce per square meter of façade panel can be generated annually (0.54 lbs./ft²) which could effectively meet 9% of summer nutritional demands for building occupants. The façade temperatures can be reduced between 10^oF-36.95^oF (5.56^oC-20.53^oC) with approximately 20% reductions in cooling energy, and positive impact on reducing urban heat island. A living façade can effectively remove pollutants from the natural ventilation air stream, measured at a maximum of 5.6% reduction in PM2.5 for the living façade compared to the control. An average of 14.26 liters of rainwater per square meter of façade per day (0.35 gal/ft²/day) can effectively redirect all the rainfall on the roof from storm drains into primary irrigation. In addition, field observations revealed enhanced access to nature for building occupants, wildlife habitat and biodiversity.