The significance of indoor air emissions in life cycle assessment of dwellings

Life cycle assessment (LCA) is a commonly used tool to assess the environmental performance of buildings. In LCA, the dwelling is assessed from cradle to grave: several environmental aspects of the winning of raw materials, the production of building materials, the use phase and the waste treatment are assessed. Current LCA tools, however, do not address the indoor environment, but have a main focus on the environmental effects of the production and waste treatment of building materials and of energy consumption in the use phase. In this study, a methodology was developed to include the damage to human health due to emissions from building materials to the indoor air in building LCAs. This damage can be compared with the damage to human health associated with the construction and demolition phase of the building, including the production of the building materials. It was shown that for the Dutch reference single-family row house, these health damages have the same order of magnitude. Indoor exposure to pollutants emitted by building materials should thus be included in the life cycle assessment of dwellings in order to make the assessment better reflect full impact of the life cycle. The consequences of these findings for the environmental modelling of houses based on life cycle assessment will be discussed.