The Net-Zero Energy Building Standard project was sponsored by the City of Tucson Office of Conservation and Sustainable Development. Pima County Development Services, Building Safety and Sustainability was the principle research group with assistance from the University of Arizona College of Architecture and Landscape Architecture and Tucson Water. The Net-Zero Energy Standard has a prescriptive residential section and a prescriptive commercial section covering apartments, office and retail. These building types represent approximately 30% of total energy use in the metro area. The Net-Zero Energy Standard also has a performance section for both residential and commercial that will allow buildings that cannot use the prescriptive path to achieve a net-zero certification by using energy modeling software.