The Solar Energy Center at the University of Central Florida will kick off a 12-week online course on building zero-energy homes, or, I suppose, retrofitting your existing one. Courses cover things like water heaters, windows, HVAC, plug loads, etc. You can register here.

Nuts and bolts information like this is going to increasingly become important. Architects and building professionals often say that energy efficiency for the most part revolves around design choices and appliances. In Europe, there are already 10,000 examples of the "PassivHaus," zero-energy homes for cold climates with relatively small heaters. Amory Lovins, the celebrated head of the Rocky Mountain Institute, lives in a house in the Rockies with no heating system. It stays warm because of "superwindows" and good insulation. (Sustainable Spaces did an energy audit on my house. They said I could put a dent in my bills just by sealing the 1931-era heating duct.)

Zero-energy homes also don't necessarily cost more than regular homes. But that depends on how you build. If you have to educate your contractor, it might cost 25 percent more. So if you're interested, tune in.