If you are keen on this, see Amory Lovins talk on buildings:
Short version: <a href="http://www.youtube.com/watch?v=DvmHJNeif24" rel="nofollow">http://www.youtube.com/watch?v=DvmHJNeif24</a>
Long Version: <a href="http://www.youtube.com/watch?v=O5txQlEI7bc&#38;feature=channel" rel="nofollow">http://www.youtube.com/watch?v=O5txQlEI7bc&#38;feature=chann...</a>