In Madison, Wisconsin, today, Jerry talked with providers of the Wisconsin Green Built Home assessment program, a third-party certification of home energy efficiency. About 30% of new homes built in Madison are now certified, but the number seems to have peaked at that percentage. The program estimates that only 2% of homes in other parts of the state are Green Built certified. This is in a very cold state, where winter temperatures of zero Fahrenheit and below are not uncommon. (Remember all those December NFL playoff games in Green Bay on frozen fields?) It seems hard for most green building certification programs to crack the 30% barrier, and to reach that number is common only in a few places, such as Austin, Tucson and Portland, that I know of.