Assessment of the environmental performance of buildings: A critical evaluation of the influence of technical building equipment on residential buildings

Sustainability assessments of buildings using the life cycle approach have become more and more common. This includes the assessment of the environmental performance of buildings. However, the influence of the construction products used for the fabric, the finishing, and the technical building equipment of buildings has hardly been described in literature. For this reason, we evaluated the influence of the technical building equipment and its impact on the environment for different residential buildings. Five residential buildings were evaluated by applying the methodology of life cycle assessment (LCA) (ISO14040) expressed using quantitative assessment categories according to prEN15978. Results show that the optimization of energy performance has already reached a high level in Austria, so that the overall potential for possible improvements is quite low. Especially in low-energy and passive-house-standard residential buildings, the limits for energy optimization in the use phase have mostly been achieved. In contrast to this, the integrated LCA (iLCA) findings attribute a high optimization potential to the construction products used for the technical building equipment as well as to the building fabric and finishing. Additionally, the passive house shows the lowest contribution of the technical building equipment on the overall LCA results. The iLCA findings suggest that it is recommended to include the technical building equipment for future assessments of the environmental performance of buildings. It is also suggested to use a broad number of environmental indicators for building LCA.