Wendy Tremaine and Mikey offer advice for those looking to buy or build a sustainable home. Wendy emphasizes that property taxes are the most significant long-term financial burden and suggests living somewhere inexpensive. Mikey warns about the difficulties of code enforcement when building unconventional structures like paper domes. They recommend remodeling existing structures as the "greenest" and most cost-effective option, citing their own success in remodeling a 1967 mobile home.