Steel Buildings in Europe

Part 2: Concept Design 2 - 5 Other typical weights are illustrated in Table 1.2. Table 1.1 Typical imposed loads for offices (kN/m 2 ) En 1991-1-1 Category Application Imposed Loading Partitions Ceiling, Services, etc. B Offices - general 2,0 – 3,0 0,5 – 1,2 0,7 C1 Areas with tables 2,0 – 3,0 0,5 – 1,2 0,7 C2 Areas with fixed seats 3,0 – 4,0 0,5 – 1,2 0,7 C3 Areas open to crowds 3,0 – 5,0 C5 Areas open to large crowds 5,0 – 7,5 Table 1.2 Typical weights for building elements Element Typical weight Precast units (Spanning 6 m, designed for a 5 kN/m 2 imposed load) 3,5 to 4,5 kN/m 2 Composite slab (Normal weight concrete, 140 mm thick) 2,8 to 3,5 kN/m 2 Composite slab (Light weight concrete, 130 mm thick) 2,1 to 2,5 kN/m 2 Services (lighting) 0,25 kN/m 2 Ceilings 0,1 kN/m 2 Steelwork (low rise 2 to 6 storeys) 35 to 50 kg/m 2 Steelwork (medium rise 7 to 12 storeys) 40 to 70 kg/m 2 1.2.4 External Loading Roofs are subject to imposed loads, to be taken from EN1991-1-1, typically 0,4 or 0,6 kN/m 2 . Roofs are also subject to snow load s, which should be determ ined from EN 1991-1-3. Wind loads should be calculated from EN 1991-1-4. The determination of these loads is covered by other documents in this series [2] . 1.3 Economics 1.3.1 Cost of construction A breakdown of construction cost s for a typical office building [1] is approximately as below: Foundations 5-15% Super structure and floors 10-15% Cladding and roofing 15-25% Services (mechanical and electrical) 15-25% Services (sanitation and other services) 5-10% Finishes, partitioning and fitments 10-20% Preliminaries (site management) 10-15%