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Abstract. Recognizing the need for economical, sustainable and feasible ways of food production in highly populated urban areas, a greenbox farming system has been proposed and developed by VECNA and University of Connecticut. The system uses urban warehouses to house and operate individually controlled growing boxes for massive horticultural production. An experimental study was conducted at University of Connecticut to evaluate the energy and water uses of a model greenbox. The greenbox was built with insulated fabric materials and metal frames, sized 1 m in length, 1 m in width and 2 m in height. A forced ventilation system was built on the walls with an exhaust fan on top and air inlets at the bottom. A bench platform was housed inside the box for growing short greens with pebbles as the growing media. Light and energy was provided by using LED lamps hanging about 1 m above the growing platform. A hydroponic system was constructed to provide nutrient solutions to the growing platform. Properties of the nutrient solution, including temperature, pH, conductivity and water level, are continuously monitored by a Nutrient Controller Hub. The interior environment of the greenbox, including light, temperature, humidity, and CO2 concentration, were measured and regulated by an IPonic 614 Environmental Controller. The greenbox was located in a warehouse with available power and water supply. Separate sets of sensors were used to measure the environmental conditions inside and outside of the warehouse. All the environmental data were collected and transmitted to a dedicated computer for analysis. Lettuce was selected for this study. Young plants were transplanted into individual containers on the platform. Daily growing parameters and water use were measured manually with a LAI meter and a weighing lysimeter, respectively. The experiment was run for a 6-week period in winter climate. The results indicate that the proposed structure was capable of providing climate for lettuce to grow and mature with good quality, and that the energy and water uses were comparable with traditional greenhouses. More experiments are planned for tests in different climatic conditions.