Remember the energy conservation industry? In the '80s I was part of it. I was a house doctor. My partner and I would arrive at a house, set up our blower door, peek through our infrared scanner, test the furnace, and use other house-doctor equipment. But more important than these gadgets was the knowledge, gained from ten years of research at Princeton University, of where and how most buildings lose energy. Studying hundreds of buildings under real-life conditions, the researchers found many ways that heat escapes by bypassing the usual weatherization measures of weatherstripping and caulking. These thermal bypasses can greatly compromise a home's comfort, contribute to moisture problems, and add significantly to energy bills (see