Steel Buildings in Europe

Part 2: Concept Design 2 - 30 Figure 3.17 Portal frame with intermediate floor 3.6.2 Portal frame with external mezzanine 1 1 Mezzanine Figure 3.18 Portal frame with external mezzanine Offices may be located externally to the portal frame which creates an asymmetric portal structure (as illustrated in Figure 3.18). The main advantage of this framework is that large columns and haunches do not obstruct the office space. Generally, this additional structure depends on the portal frame for its stability (the members often have nominally pinned connections to the main frame) and the members can be relatively lightweight.