Houses are getting too complicated. There are many people living in New England in houses that are warm and comfortable and only heat with wood and passive solar. My friend Steve is such a person. His house was built in the early eighties with large windows on the south and a descent amount of insulation by eighties standards. The temperature in his house is always 70 degrees in the winter even though he usually only fires up the wood stove a couple times per day. He uses no other heat source. When you build a new house at any budget level, it seems to be not a question that there is a significant heat system. As an architect, I periodically go to seminars on super-insulated passive solar houses where I hear that radiant heat is overkill and that you should consider a simple type of electric (future photovoltaics) backup heat near the plumbing (but you may never use it). No heat system, radiant or otherwise is a very hard sell as an architect. Maybe I should take people to Steve's house and let him be the salesman.