Abstract: Environmentally heated and cooled pre-fabricated insulated concrete building is provided with a continuous layer of foamed insulation within all exterior walls. The building is constructed preferably of reinforced concrete having an outer and an inner wall connected together along the lower edge. Each section or unit of the wall is provided with an interlocking shape along the lateral edges for interlocking with adjacent panels or units. The walls are assembled at the job site and filled with a foam insulation. The outer concrete wall is provided with ducts therein and damper and blower controls which provide solar heating in cold weather and air circulation cooling in hot weather.