Thermal Mass One of a home's main purpose is to provide shelter from the elements. Inside climate must be kept comfortable when when outside climate is not. Standard building practices accomplish this at a high energy a nd building cost. Earthships use natural phenomenon and ingenuitive design to provide comfortable living efficiently. Thermal Mass is used to store heat and regulate temperature for the living area.
Tires filled with dirt and bermed walls help create a natural barrier from the elements.
One way to do this is with renewable energy. Plants love wastewater and thrive off it. Often these planters can be indoors also benefiting form t he passive solar deign. These indoor plants can provide food for the inhabitants making Earthships very self sufficient. Blackwater or toilet water has to be dealt with a little differently.