Open to students and professionals worldwide, the Architecture at Zero 2013 competition is challenging participants to create a design for a new, roughly 150 unit mixed-use residential apartment building located in the Tenderloin neighborhood in San Francisco, California. With the aim of being as close to zero net energy as possible, the building must be a mix of affordable and market rate housing units and include a full neighborhood-serving grocery store on the ground level. The competition is presented by Pacific Gas and Electric Company (PG&E) and AIA San Francisco, in partnership with the Tenderloin Neighborhood Development Corporation (TNDC). Submissions are due October 1. To register, and for more information, please visit here.