It seems that whole cities are now going solar:
The Santa Monica City Council voted in April to approve an ordinance requiring rooftop solar systems for all new construction in the City of Santa Monica—both residential and commercial.
Santa Monica joins other California cities San Francisco, Lancaster and Sebastopol in implementing solar requirements at time of construction. The requirements will add between $3.27-3.54/sq ft in construction costs – 33-37% below current solar market prices. The energy savings will more than offset mortgage pricing increases – lowering ownership costs from day one.