Sustainable steel and composite constructions for multifunctional commercial buildings

Rising cost pressures and the prospect of quick returns have led to an increase in mono functional buildings since the 1970s. These prevent the adaptation to changing user requirements with little monetary outlay. Lack of marketability, increasing vacancy and early demolition are often the consequences. Main objective of the AIF/FOSTA research project P1118 [1] is to develop planning recommendations for multifunctional usable buildings. Adaptability to changing needs will increase marketability and value stability as well as extend the lifetime of the buildings. This not only increases the economy but also the resource efficiency. First of all, the paper explains the ecological and economic requirements for modern buildings, which are based on current certification systems. In this context, the expected lifetime of primary and secondary building components are also dealt with. Subsequently, relevant types of use as well as requirements for essential building parameters are presented. In a comparison, the ecological expenses and costs are assessed for four selected composite structures. For the multifunctional building structures an extension of lifetime is considered and the environmental and monetary impacts are assessed. Furthermore, the influence of the structure on the building foundations is analysed. The investigations present the effects of the building masses on the foundations for two different soil conditions. Finally, the investigations show that variable usable buildings with a longer lifetime lead to a better sustainability.