Importance of technical installations in whole-building LCA: Single-family case study in Flanders

Abstract

When calculating buildings' environmental impact through life cycle assessment (LCA), simplifications in the life cycle inventory phase of technical installations are common. Often authors argue that these simplifications are essential to minimize time and effort. However, it is unclear to what extent these simplifications are justified. The challenge lies in establishing simplified models that do not compromise the robustness of results, which first requires detailed LCAs. Therefore, this paper aims to acquire knowledge about (1) the significance of individual components in heating and ventilation systems’ design, (2) the relative contribution of technical installations to embodied and life cycle impacts at building level, and (3) the difference between a detailed and simplified approach to derive guidelines for simplified calculations. In this research, a Flemish single-family dwelling is adopted as reference building, including six heating and four ventilation scenarios. Firstly, the current state-of-the-art in research on the environmental impact of technical installations is outlined. Secondly, an extensive data inventory is performed, suggesting different approaches to address data limitations. Finally, the environmental impact is calculated over a 60-year study period, following a cradle-to-grave methodology. The results show that a simplified approach, considering only generation systems, underestimates embodied and life cycle impacts by 8–12 % and 4–6%, respectively. Technical installations contribute 12–33 % to the embodied impacts of the new build dwelling, whereas in the context of the overall life cycle impact, technical installations contribute 5–20 %. Moreover, the study highlights the environmental significance of individual heating and ventilation components beyond generation systems.