ABSTRACT
ABSTRACT The service lives of building elements and building integrated technical systems (BITS) can vary within a large interval depending of the data sources used. It can lead to inconsistencies when performing building related assessment (such as environmental life cycle assessment (LCA) or life cycle costing (LCC)). To that purpose, this study presents a method for the estimation of uncertainties arising from the building element service life in the context of building Life Cycle Assessment (LCA) and Life Cycle Costing analysis (LCC). First, different building elements’ and materials’ service lives sources are collected in the international literature and compiled in a structured database. Second, the values are statistically sampled, and probability distributions of service lives are derived to serve as input data for the LCA and LCC of buildings’ case studies. To illustrate the approach, LCA and LCC were conducted on four newly built Swiss dwellings. The related uncertainties arising for the variability of the service lives was evaluated with a Monte Carlo simulation. The outcome of the study showed that the greenhouse gas emissions or the costs uncertainties of the replacements represented between 6 and 16% of the total result of the buildings’ LCA or LCC. Furthermore, the uncertainties estimation of the replacements allow to compare more accurately the buildings’ environmental or economic performances. The study highlighted the interest of taking into account uncertainty estimation for the replacement phase, especially in the context of more energy efficient buildings.
