Basement enclosure

A basement enclosure adapted to be installed below ground level comprising a single floor in a horizontal plane, vertically extending walls attached to said floor at essentially right angles thereto around the entire periphery of said floor and thereby forming an enclosed interior zone with said zone being substantially entirely open at the top of said walls, said floor and walls together forming a rigid, self-supporting structure not requiring additional support to achieve rigidity for final proper installation and use, the top of said walls being so designed so as to be readily adapted to engage horizontal supports extending across from the top of one wall to an oppositely disposed wall, so as to receive a building to be constructed thereon and the exterior of said floor and walls having attached thereto and being completely covered with a separate outer substantially continuous contiguous shell constructed of a material impermeable to moisture and gas.