What does freedom from utility bills look like? Is it geothermal energy and spray foam insulation with a dash of passive ventilation? Wind power, SIPs, and water-saving features? Straw-bale construction oriented for passive ventilation and solar exposure? There are many different recipes for energy efficiency, and the ingredients often depend on climate, cash flow, and available resources. But those who have tasted the sweet success of net zero will tell you it boils down to three basic principles: conservation, renewable energy production, and homeowners who are on board with the idea.