Abstract: A method of producing a finished building from a skeletal building structure made up of a plurality of vertically spaced floor slabs, each having an upper surface, is disclosed. A wall supporting structure is secured to the floor slabs, and exterior wall panels are secured to the wall supporting structure to define a plurality of enclosed regions bounded by an upper slab, a lower slab and a surrounding wall comprising a plurality of the exterior wall panels. Each enclosed region has an interior that is isolated from wind and precipitation relative to the environment surrounding the skeletal building structure. From positions on the upper surfaces of the floor slabs and within the enclosed regions, interior wall components are installed on at least one of an interior side of the external wall and the wall supporting structure.