He also employs the same approach in his other work, which includes multiple housing and other building types. Barba's advocacy of ecologically responsible architecture has led him to tunnel into hillsides, landscape rooftops, and use quarries and rock overhangs to shelter his houses, all in an effort to reduce energy consumption and blur the division between building and landscape. This book features 12 of his best residences, located in Spain, Portugal, the Greek islands, and in California. It is informatively written by author and journalist Michael Webb, who also writes on architecture and design for leading magazines around the world.