Click on each image to view an interactive 3D model of the different roof shapes
A Gable Roof is most probably the most common of roof shapes. It is when two of the side walls are build-up to the underside of the roof with the roof projecting over the walls. If the walls were to be build up higher than the roof it would be called a Parapet Roof.
A Dutch Hipped roof is very similar to a Hipped Roof with the hip-apex off-set to the wall creating a cantilever hipped end, however the end are cut-off and the gable wall is build up to create the "Barn Type" look.
A Flat Roof is simply what is says, a flat roof. This roof type can be constructed with only loose timber referred to as Rafters or roof trusses can be used if there is enough height available to accommodate a stubbed-truss design.