A pair of doctors in town decided that they wanted to build a guest house behind their home, and they decided that they wanted it to be very energy efficient. I think the term the builder used was "Green Building". The house is fairly small, less than 900 square feet, which by itself makes it affordable to heat. But this house has several other key features, including hot water tubes that run through the sub-flooring. These radiate heat up into the room. The house is also sealed up with plastic ans has some high quality insulation in all of the walls. Add to that the passive solar heating from the high, south facing windows and the on-demand water heater in a box system and the energy costs will be less than I used to spend for a pizza.
Posted by Jeff Jones