Underground Architecture Websites
Underground Buildings
SubsurfaceBuildings.com explores specific examples of underground buildings and examines concerns like environmental issues, energy efficiency, security, psychological resistance, and safety.
7,293,506 
$ 8.95
Green Home Building: Index
Greenhomebuilding.com focuses on sustainable architecture, natural building, solar energy, ecology, water and forest conservation, recycling, greenhouses, adobe, cob, strawbale, cordwood, papercrete, earthbag and vernacular architecture, with related resources of books, videos and links.
621,850 $ 1,200.00