Steel Buildings in Europe

Part 2: Concept Design 2 - 6 Preliminaries represent the costs of the site management and control facilities, including cranes, storag e and equip ment. Site preliminaries can vary with the scale of the project and a figure of 15% of the tota l cost is of ten allowed for steel in tensive cons truction reduc ing to 12% for higher levels of offsite prefabrication. The superstructure or fra mework cost is rarely m ore than 10% of the to tal, but it has an im portant effect on other costs. For ex ample, a reduction of 100 mm in the ceiling floor zone can lead to a 2,5% saving in cladding cost (equivalent to 0,5% saving in overall building cost). 1.3.2 Benefits of steel construction Steel construction offers m any benefits to the client/user in o peration including:  Column-free spans, permitting flexibility in use  Ease of extension and adaptation in the future, including needs for re-servicing  Variety of cladding and roofing systems  Long design life and ease of maintenance  Energy efficient design. These benefits of steel construction are explored in Section 2. 1.3.3 Cost of ownership / occupancy It is estimated that the total cost of running a building during a 60 year design life may be 3 to 5 times the cost of initial construction. Major com ponents in the longer term costs include:  Direct running costs of heat, lighting, air conditioning  Refurbishing the interior, m inor redecoration every 3-5 years, m ajor refitting every 10-20 years  Replacing the services, approximately every 15-20 years  Possibly re-cladding the building after 25-30 years. The European Directiv e on Energ y Sa ving in Buildings now requires that office buildings carry an ‘energy pass port’ which defines the energy use and energy saving m easures. Many modern buildings are designed with energy saving measures in m ind, including double skin facades, thermal capacity and chimneys for natural ventilation and photovoltaics in roofing. 1.4 Construction programme A typical construction programme for a medium-sized office building is shown in Figure 1.4. One of the advantages of steel construction is that the initial period of site preparation and foundati on construction permits sufficient tim e for off-site fabrication of the stee l structure into a ‘kit of parts’. This is known as ‘Fast track’ construction.