Making a house energy efficient is only the start of the fix.. If the house is an hour's drive from your place of work, not using energy to heat the thing is rather insignificant.
Older buildings will have to be upgraded so you can afford to live in them, and new buildings constructed will have to be built for the long term future. They will have to create energy and be located closer to food supply and place of work. They will also have to be built using less energy and materials per occupant. We are running out of cheap energy and abundant resources. Whatever you do to reduce consumption is worth the investment because when we run out of oil everything will cost a lot more to do.