and saves lives. Besides Underground Housing, there is also the concept of Earth Sheltering.

From Wiki:

Underground Living-

Besides obvious novelty, underground living offers additional benefits when compared to living in traditional buildings, such as a nearly constant comfortable temperature without the need for additional insulation, quiet, resistance to hurricanes, tornadoes and most weapon systems and the unobtrusiveness of such buildings on the landscape. One of the greatest advantages is energy efficiency.<1> The stable subsurface temperature of the Earth saves around 80% in energy costs. If married to solar design, the energy bill can be completely eliminated. Additionally, the noise insulation of the surrounding earth makes underground homes exceptionally quiet, and with a smaller surface area, fewer building materials are used. However underground living can be easily affected by flooding and sometimes special pumping equipment is necessary.



Earth Sheltering-

Earth sheltering is the architectural practice of using earth against building walls for external thermal mass, to reduce heat loss, and to easily maintain a steady indoor air temperature. Earth sheltering is popular in modern times among advocates of passive solar and sustainable architecture, but has been around for nearly as long as humans have been constructing their own shelter