Rigid building event. Energy efficient.

Construction site of an entry in a competition for the most energy efficient house that can be built economically. The walls behind the saw are blocks filled with water and an air space. The water is heated by the sun, the air space traps the heat. In the summer, shade trees and awnings keep the sun from hitting the blocks. The house itself is beautiful. If I can get more pics on Friday when they open it to the public, I'll post one here.