Multifunctional commercial buildings in steel and composite construction. Part 1-basic principles for assessment, planning and construction

Within the AIF/FOSTA research project P881 [1], the use of steel and composite structures in office and administrative buildings in terms of flexibility for different types of office organization and sustainability was examined focusing economics and ecology. This has been reported in various articles (see e.g. [2] to [5]). The subject of the AIF/FOSTA project P1118 [6], which is about to be completed, is the design and evaluation of multifunctional commercial buildings in steel and composite construction. The core idea of the research project is the creation of adaptable multi-storey buildings for urban areas in order to increase the value stability and marketability of the real estate and to extend the useful life. In this process, the moderate additional expenditures for the construction of buildings are compared with the benefits in terms of economy and ecology. Part 1 of the article starts with the problem outline and basics of assessing sustainability with a focus on the economic efficiency. It deals with the life cycle costing, investment calculation methods and real estate economic parameters. The third section explains planning aspects for creating multifunctional buildings. Based on the building typologies and the assignment of usage forms to floor levels, strategies for the consideration of different initial and subsequent uses for planning typical urban building blocks are presented. Essential aspects are the choice of building width, clear storey height, the access via building cores, corridors and shafts for technical building equipment. The key criteria for the design of multifunctional storey buildings are summarized. Section 4 provides an overview of the load assumptions for multi-storey buildings in various types of use and ceiling systems in steel and composite construction. At the same time, new developments in multifunctional ceilings will be discussed. This is followed by investigations and parameter studies on the ecology and economy of various slim floor systems and ceilings with downstand beams. In this context, the questions are also pursued, "what differences arise in ceiling systems with and without inner supports?" and "how do different imposed load levels affect?"