Earthship Design and Construction: What You Need to Know An earthship is a type of sustainable, mostly off-grid dwelling that uses on-site materials and passive systems to cut energy, water, and waste needs. This guide explains earthship basics, core design principles like thermal mass and passive solar orientation, traditional and modern materials, off-grid water and power systems, permitting realities, and a practical DIY build roadmap. Readers will learn which earthship strategies work for different climates, when to choose code-friendly hybrids, and how to plan a realistic budget and timeline. TL;DR: - Average household water use is about 80–100 gallons per person per day; size cisterns accordingly (example: 3 people × 80 gpd × 30 days ≈ 7,200 gallons). - Use thermal-mass walls plus continuous insulation to meet modern R-value targets (aim for R-20 to R-30 wall performance in cold climates). - Start with a pilot test wall or a small hybrid build, meet your local building official e...