This home includes the principles of passive solar design: Orientation, ventilation, insulation, and mass. It utilizes southern orientation with properly sized window overhangs and heat-rejecting glass, proper ventilation including a whole house fan and solar powered attic fans, abundant insulation, and a high level of thermal mass (concrete floors and window sills etc.). Even in the hot north county climate, the house maintains comfortable interior temperatures with no air conditioning. A 3 kW PV array provides almost all the electricity needed.