Steel Buildings in Europe

Part 2: Concept Design 2 - 3 Once the co ncept des ign is agreed, the detailed design of the building and its components is usually undertaken with le ss direct interaction with the client. Connections and interfaces between the com ponents are of ten deta iled by the fabricator or specialist designer but the lead architect should have an understanding of the form of these details. 1.2 Client requirements 1.2.1 Spatial Requirements Client requirements may be defined firs tly by general physica l aspects of the building, e.g. the num ber of occupants a nd their range of functions, planning modules or floor-to-floor zones. Minim um floor loadings a nd fire resistance periods are defined in national regulations , but the client m ay wish to specify higher requirements. Examples of general client requirements are: Occupation density 1 person per 10 m to 15 m 2 Useable floor area : Total area 80 to 90% typically Floor-to-floor zone 3,6 m to 4,2 m Floor-to-ceiling zone 2,7 m to 3 m typically Planning module 1,2 m to 1,5 m Imposed loading 2,5 to 7,5 kN/m 2 Fire resistance R60 to R120 The floor-to-floor zone is a key param eter, which is influenced by planning requirements on overall building height, natural light, claddi ng cost and other aspects. 1.2.2 Service requirement Other client requirem ents m ay be defi ned under the heading of ‘servicing’, which includes Inform ation Technology and other comm unication issues in addition to ventilation, lighting and other servicing requirements. In most inner city projects , air cond itioning or co mfort cooling is essen tial, becaus e nois e limits the u se of natura l ventila tion. In sub-urban or m ore rural sites, natural ventilation may be preferred. Design req uirements f or building serv ices are usu ally dete rmined by regulations in the country where th e structure is to be constructed and are a function of the external and internal environments. Typical examples of client requirem ents for design of the prim ary building services are: Fresh air supply 8-12 litres/sec per person Internal temperatures 22  C  2  C Cooling load 40-70 W/m 2 Thermal insulation (walls) U < 0,35 W/m 2  K