by Harris Hyman I look at solar-heated buildings as belonging to several "generations," or design eras. The first-generation buildings were outright experiments conducted prior to 1974: the Thomaston Solaris system, the Trombe-Michel house, the four Hottle systems developed by the Massachusetts Institute of Technology, and similar projects. The second generation began after the OPEC meeting of 1973 and attracted serious adherents who sat in the gas lines of 1974 thinking things over. (I was one of them.) Second-generation buildings were serious efforts at doing something to help with a worldwide energy crisis. The buildings constructed during this time were a wonderful combination of folk art and heavy science, often in the same building. People such as Doug Balcomb, with his
