An earth shelter, also called an earth house, earth bermed house, or underground house, is a structure with earth (soil) against the walls, on the roof, or that is entirely buried underground.
An earth sheltered house in Switzerland (Peter Vetsch)
Mandan lodge, North Dakota. c. 1908
"The interior of the hut of a Mandan Chief": aquatint by Karl Bodmer from the book "Maximilian, Prince of Wied's Travels in the Interior of North America, during the years 1832–1834"
Turf house in Sænautasel, Iceland.
In building design, thermal mass is a property of the mass of a building that enables it to store heat and provide inertia against temperature fluctuations. It is sometimes known as the thermal flywheel effect. The thermal mass of heavy structural elements can be designed to work alongside a construction's lighter thermal resistance components to create energy efficient buildings.
The benefit of thermal mass is shown in this comparison of how heavy and light weight constructions affect internal temperature
A modern school classroom with natural ventilation by opening windows and exposed thermal mass from a solid concrete floor soffit to help control summertime temperatures
An adobe walled building in Santa Fe, New Mexico
