The Craftsman-style bungalow looks normal on the outside, but the surprise is on the inside: straw bales inside the framing provide super insulation. Natural builder Lydia Doleman designed this 800-square-foot small-footprint house to last centuries, with its metal roof and strong foundation. She used reclaimed lumber and recycled materials extensively. Hot water pipes warm the earthen floors and replace energy-intensive concrete. Day-to-day usage is low impact: composting toilet, vegetative roof and rainwater catchment, LED lighting, and solar hot water.