Abstract: Apparatus and method for constructing at a given site a building having a predetermined shape with a periphery that is essentially defined by a width and a length, and the building having generally vertical walls. At a second site creating an upright structure having an interior bounded by spaced-apart and generally vertical walls but no floor, the separation of said walls serving to define an empty shell whose size and shape corresponds to that of the building that is to be constructed. Connecting horizontal beams to the interior of the upright structure so that they and the upright structure can be lifted. Positioning inside the upright structure a trailer that has the necessary load capacity to transport the upright structure over a public road. Temporarily connecting the trailer to the horizontal beams and transporting the upright structure to the first site. Disconnecting the trailer from the upright structure and removing the trailer from the interior of the upright structure.