A BUILDING
A building structure comprises an open upright rectangular main frame spanning the width of the building, one or more separate floor frames supported from the main frame, an open upright rectangular end frame extending parallel to the main frame and connected to the main frame via the floor frame, and wall and roof panels extending between the main frame and end frame. The building structure is demountable and individual components are of such a size that they can be lifted by just two adults without the need for special lifting equipment. To facilitate transportation and handling during construction, the main frame is assembled on-site as two frame halves, specifically a left hand and right hand frame half, each preferably formed from several components assembled together on-site.