Abstract: A method of building construction which involves the steps of forming a building framework that includes a slab-like floor layer having an upper surface defining a habitable area and at least one horizontal groove opening into its lower surface, providing a pattern of duct-like parts on the floor layer in accord with an arbitrarily selected room layout, providing utility lines in the horizontal groove below the upper surface and in the duct-like parts above the upper surface, and providing partition walls atop the duct-like parts to form rooms.