Relevance of simplifications in LCA of building components

This paper provides a detailed analysis of life cycle assessment (LCA) results of different building components (e.g. wooden wall, concrete roof) on different levels of simplification (from a comprehensive LCA including all materials and processes to the fully reduced component including only the main materials remaining in the component). The main objective is the determination of the relevance of materials and processes often neglected in simplified LCA of building components which aim at providing results of similar quality as comprehensive assessments with less effort. The studied simplifications are categorised in transportations of the building materials from the factory gate to the building site, some ancillary materials which are not obvious in the component, the building process itself and the associated cutting waste. The results show that transports and ancillary materials are of relevance while the building process and the cutting waste can be neglected. The heavier the used materials and the longer the transport distances the bigger is the influence of transports on the LCA results. The influence of the ancillary materials is highest for wooden constructions as a lot of screws nails and other connectors are essential.