Steel Buildings in Europe

Part 2: Concept Design 2 - 26  Atria improve the efficient use of the building, and reduce the running costs. 4.2.1 Influence of building height The building height has a strong influence on the:  Structural system that is adopted  Foundation system  Fire resistance requirements and means of escape  Access (by lifts) and circulation space  Choice of cladding system  Speed of construction and site productivity. For taller b uildings, s trategically p laced concrete o r b raced steel cores ar e usually adopted. Ultra tall build ings are influen ced s trongly by th e s tabilising system, but are outside the scope of this guidance. Sizes of lifts and their speed of movement also becom e important considerations for tall buildings. Depending on the Regulations for fi re safety in the particular country, the use of sprinklers m ay be required for buildi ngs of more than eight storeys (or approximately 30 m high). 4.2.2 Horizontal coordination Horizontal coordination is dominated by the need on plan for defined zones for vertical access, safe evacuation in fi re, and vertical se rvice distribution. Positioning of service and access cores is influenced by:  Horizontal distribution systems for mechanical services  Fire r esistance requ irements, which may control evacuation routes and compartment sizes  The need to distribute the stabilizing systems (bracing and cores) effectively throughout the building plan. Figure 4.1 and Figure 4.2 show typical arrangements that satisfy these criteria. An atrium may be incorporated to incr ease lighting to the o ccupied space and to provide high value circulation areas at ground and interm ediate levels. The design requirements for atria are:  Support to the long span roof of the atrium  Access routes for general circulation  Fire safety measures by smoke extraction and safe evacuation routes  Light levels and servicing to internal offices.