Steel-frame buildings consist of a skeletal framework that carries all the loads to which the building is subjected. The sections through three common types of buildings are shown in Figure 1.1. These are

1. Single-storey lattice roof building 2. Single-storey portal frame building 3. Medium-rise braced multistorey building

These three types cover many of the uses of steel-frame buildings such as factories, warehouses, offices, flats and schools. A design for the lattice roof building (Figure 1.1a) is given, and the design of the elements for the braced multistorey building (Figure 1.1c) is also included. The design of portal frame is described separately in Chapter 9.