Interlocking support posts form an interlocking rack system which may have a single mold which provides both a male and a female joinder member. Between the support posts can be mounted panels such as solar panels. Under the support posts can be installed a roof stand off assembly which prevents water from weakening the roof. Various combinations of construction members offer a cost effective building block array of mounting panels, wind turbines, and any appliance on a roof and/or anywhere in a building. A two recess mounting bracket is ideally suited to mount solar panels on a roof. A lower recess can be fastened to a bolt anchor on the roof. The opposing recess can secure a mounting clip which attaches directly to the solar panel. Identical support posts can interlock. Various embodiments include conduit clasps, slider tracks, mounts for cabinets, sign posts, and thru roof screwed anchors.