1. Start with an existing house. Obviously you can go out of your way to break this rule, but when you remodel, you are reusing an existing structure. Both building and remodeling are wasteful processes. But by remodeling, you are creating less waste, using less energy and putting your money into more labor than materials, which helps support your local economy. A side benefit of not building new: Existing buildings are more likely to be close to established infrastructure, trees and cool old neighbors with lots of stories.