I was looking through some old house pictures last night and was reminded of how our design and subsequently the house, came about. The process essentially melded a list of features we wanted into a house shell and floor plan. We prioritized our feature list and separated the "must-have" features from the rest. We then spent weeks searching the Internet for designs we liked and then combined those to make our own plan, which we handed off to an engineer.
One thing that I knew for sure was that I wanted the house to be energy efficient. There are several ways of accomplishing energy efficiency including active solar features, passive solar design, insulating the shell, and installing energy saving/energy efficient fixtures. The heart of our design incorporates passive solar features and earth sheltering and then adds higher than required levels of insulation. The area of south-facing glass totals about 8% of our above ground floor space, which provides a lot of solar gain on sunny days, but not too much in late spring and early fall, when we don't want or need the extra heat.
Active solar features were to include domestic hot water production and hot water radiant floor heating located in cool zones. We had eliminated north-facing windows to reduce heat loss but still had a north side master bathroom that would definitely be a cool zone.
So more than any other part of the house, seeing all of the solar calculations and even seeing the piping, tanks, controllers, and all of the rest installed in the basement and the collector on the roof we not enough to make a believer of me. But once I took my first shower with almost endless free hot water and then stepped out onto the warm bathroom floor, that did it. The only problem is that I now get depressed on cloudy days.