XI. Green Building, Ecovillage Design, and Land Preservation The thing about buildings and land-shaping is that they are the longest-term statements about who you are and what you value.You can change your garden every year, rearrange your demographics over the course of a decade, but most buildings last at least 30 years. For most of us, the designs of our community and major buildings are the the largest, most permanent things we'll ever manage...