More generally, people often build houses out of the nearest available material, and often tradition and/or culture govern construction-materials, so whole towns, areas, counties or even states/countries may be built out of one main type of material. For example, a large fraction of American houses use wood, while most British and many European houses utilize stone or brick.
In the 1900s, some house designers started using prefabrication. Sears, Roebuck & Co. first marketed their Houses by Mail to the general public in 1908. Prefab techniques became popular after World War II. First small inside rooms framing, then later, whole walls were prefabricated and carried to the construction site. The original impetus was to use the labor force inside a shelter during inclement weather. More recently builders have begun to collaborate with structural engineers who use computers and finite element analysis to design prefabricated steel-framed homes with known resistance to high wind-loads and seismic forces.
One tool of earthquake engineering is base isolation which is increasingly used for earthquake protection. Base isolation is a collection of structural elements of a building that should substantially decouple it from the shaking ground thus protecting the building's integrity and enhancing its seismic performance. This technology, which is a kind of seismic vibration control, can be applied both to a newly designed building and to seismic upgrading of existing structures.
Normally, excavations are made around the building and the building is separated from the foundations. Steel or reinforced concrete beams replace the connections to the foundations, while under these, the isolating pads, or base isolators, replace the material removed. While the base isolation tends to restrict