Livscykelanalys i det tidiga projekteringsskedet: En studie om användning och utredning av arbetsgång

Sammanfattning

Introduction – The construction industry is facing changes with stricter requirements regarding climate reports and limit values. New tools that can be used to reduce a building’s climate impact are in demand from designers. The aim of the study was to investigate the use of BIM-based LCA tools and to investigate a workflow for the use of life cycle assessment in the early design stage. Method – The present study is based on a literature review, interviews and a case study. Through the techniques, qualitative and quantitative data were collected to answer the questions in the study. The interviews were conducted with people working in the construction industry to collect useful data. Data collected from the literature review and interviews formed the basis for the case study which were carried out on an attefall house. The attefall house was used to investigate the impact of the Level of Detail on the LCA-results in the One Click LCA software. Results – The result of the study was that only one of the respondents used BIM-based LCA-tools. One of the benefits with using LCA in an early design stage was the possibility to study different design, material and construction solutions with regard to climate impact, among other things. In the case study´s analysis 1 it was presented that LOD200 resulted in 31,7 precent lower Global Warming Potential (GWP) than LOD300. In analysis 2, the building elements that generated the highest GWP-result was the foundation and frame. Analysis – The use of BIM-based LCA-tools was low. The respondent who used BIM-based LCA-tools did so throughout the hole design process, but with more focus in the early design stage. Several benefits were presented both from previous research and from the interview respondents. The respondents and previous research agreed on most of the benefits and noted that the use of BIM-based LCA-tools in the early design process could reduce the building’s climate impact. In the analysis of the result from the case study, it could be concluded that the level of detail of the BIM-model affected the LCA-result by underestimating the GWP-result. This emerged during both the case study and in the literature review of previous research. The case study did not identify incorrect “hot spots”, which pervious research claimed could occur at a lower level of detail in the BIM-model. Discussion – During the discussion, connections emerged between previous research and the study’s results. It was presented that the study contributed with knowledge to the industry, which was lacking according to the respondents. Based on the method discussion, it was noted that more interview respondents would have strengthened the external validity of the study. Based on the case study, further research on the subject can be carried out on larger and more complex buildings.