Simplifying LCA use in the life cycle of residential buildings in Sweden

Licentiate thesis, 2019

This thesis discusses the use of environmental life cycle assessment (LCA) in the building life cycle. While the life cycle of a residential building is an important source of environmental concern, knowledge about LCA remains scarce and sporadic in most construction companies. In anticipation of a regulatory requirement for LCA-based climate declarations, construction companies in Sweden are expressing increasing interest in applying LCA to residential buildings. However, despite this interest, many companies experience difficulties making effective use of the potential that LCA may have to shape environmental action in the building process.

The aim of this licentiate is to clarify the conditions that hinder a more effective use of LCA. It addresses whether LCA is too complex to be used effectively, and whether there are other conditions that may require attention. In addition, it examines whether simplification of LCA may be a meaningful way to stimulate LCA use in the building life cycle.

A literature-based exploration of LCA use in the building context was conducted. The results of this exploration identify central problems with LCA use for residential buildings and focus specifically on the complexity of building LCA. In addition, this licentiate provides an empirically informed account of the experiences and perceived problems with residential building LCA in Swedish construction companies. Perceptions of LCA analysts and environmental managers were explored in an interview-based study. In addition, nine LCA studies were conducted on multifamily residential buildings using data from these construction companies.

The findings in this licentiate indicate that while complexity should not be discounted, it cannot explain the ineffective use of LCA in the building life cycle. Even if LCA may be difficult to understand, the types of complexity involved are not essentially different from those tackled successfully elsewhere in the building process. In addition, there are several other reasons that explain why LCA is considered difficult to use. Problems with demand, resources, data availability, and competence all contribute to an environment in which performing LCA is more difficult than necessary.

A review of available LCA simplification strategies is presented to tackle complexity in building LCA. A systematic search and review was conducted using the simplification literature. The results suggest a wide variety of established simplification techniques, following five central simplifying logics: exclusion, data-substitution, expert judgement, standardisation, and automation. These simplification strategies can be used to more easily apply LCA in a building context.

In 2022, the use of LCA-based climate declarations will become a state requirement in the Swedish building sector. In order to make more effective use of LCA in the building life cycle, it is not enough to merely apply LCA to calculate the greenhouse gas emission of a finished building design. If the ambition is to make use of the full potential of LCA for industry and ecology, it is necessary to more actively integrate LCA in the planning, design, and construction of residential buildings.