Abstract: A subterranean building structure has a footing surface and end to end matching concrete wall shell segments arranged in longitudinally abutting relation on the footings. One of the wall sections has an embedded, horizontally extending lock part, and the other has an embedded camming assembly receiving the locked part and creating relative movement of the wall segments into sealed, wedged abutting relation with the operation of manipulatable camming assembly which are accessible through the interior walls of the studded concrete wall sections. Within the concrete shell sections, wire mesh reinforcement extends substantially throughout the wall panels and rebar reinforcement is fixed to this reinforcement as well as to each lock part and camming assembly so that a continuous integrated skeleton framework extends through all walls of the basement enclosure and ties all walls together in one integrated steel skeleton or framework.