Abstract: A building is disclosed an integrated solar heating system forming a part of the design of the building by a portion of the heating system being the structural support walls in the form of vertically disposed hollow vessels preferably made of metal. Insulation is applied to opposite sides of the vessels. A fluid is circulated from an upper manifold through heating panels to an intermediate manifold which in turn communicates with the upper end of the vessels. A lower manifold communicates with the lower end of the vessels and with said upper manifold by way of a pump. Ducts for circulating air to rooms of the building are in heat exchange relationship with the hollow vessels.