Foundation (engineering)
A foundation is the element of a structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (Geotechnical engineering) in the design of foundation elements of structures.
Earth shelter
Typically earth sheltered structures are more costly to build compared to a regular house. This is due in part to the cost of excavating the earth, having to use structural materials in the walls and the roof which withstand greater load, and increased expense on waterproofing. Many financial institutions outright exclude financing on earth-berm homes or require this type of property to be common for the area. However, as with other types of buildings the cost of construction varies greatly. For example homes built in the style of Oehler would tend to be significantly cheaper than regular houses since he emphasizes the owner(s) doing much of the excavation and work themself and using recycled materials for windows for example.