For builders working in California—already one of the most expensive states for new construction—a new bill winding its way through the legislature could add yet more costs. For this reason, Senate Bill 71 (SB 71) should be on the radar of developers and construction companies that do business in California. SB 71 would require all “solar-ready buildings” constructed on or after January 1, 2018, to include a solar electric or solar thermal system on their roofs. “Solar-ready buildings” include single-family residences in subdivisions with 10 or more single-family residences with an approved subdivision map; low-rise multi-family buildings; high-rise multi-family buildings and hotel/motel occupancies; and all other non-residential buildings. The solar systems would be required to be installed during construction because, as the bill explains, installing systems at that stage is more cost effective.