It is All About the Details - A Life Cycle Assessment on a Building Project in Sweden with Focus on the Level of Details in the Inventory Data

Abstract

The use of life cycle assessments within the building industry has increased rapidly during the last decade. In Sweden, new regulations regarding life cycle assessment becoming a benchmark for all new production, refurbishment as well as management of existing buildings has been suggested. However, the effects from a life cycle assessment based on comprehensive inventory data has not been thoroughly investigated. Therefore, the aim of the study was to investigate in the implication of such an assessment, both regarding the workload needed as well as effects on the results. To reach the aim, a case study where a life cycle assessment of the product stage of a building project has been conducted. The inventory data is based on articles provided in a highly detailed cost calculation of the project. When including comprehensive inventory data, several assumptions and calculations regarding size and content of an article are needed to be able to reach the information needed to choose a suitable reference material. In this thesis, these assumptions and calculations are documented in a new tool called Transformation Index. A low Transformation Index is considered beneficial, both regarding the workload needed by the analyst and the accuracy of the results. It was concluded that the transformations require knowledge regarding the building industry in general as well as specific knowledge regarding the project. Further, the case study indicated that the benefits of including more details varies depending on which impact category that is evaluated. It was also concluded that the workload and results vary significantly when using different environmental certifications and cut-offs based on Transformation Index. To summarise, it is all about the details.