A building structure consists of a first factory-constructed section (1608) defining a habitable space and having a first edge with a first channel. A second factory-constructed section (1701) defines a second habitable space and as a second edge with a second channel. An elongate member 1902 is configured to locate in both the first channel and the second channel so has to force the first edge into contact with the second edge. The building structure may be made from building components in which connecting members connect first planar sub-assemblies to said second planar sub-assemblies defining a box assembly with a connecting member at a plurality of connecting locations within the box assembly. Planar materials are attached to the large outer surfaces of the box assembly to produce a closed box assembly. Solid foam material is located within the closed box assembly. The completed structure may have integrated guttering in which the guttering has a plurality of rib-like structures extending from an inner surface of a channel and extending over a hole, thereby restricting the access of solid material through the hole and into a discharge pipe.