Footprints of failure: Quantifying carbon impacts of roof leakages in a single-family residential building

Abstract

To meet the UN Sustainable Development Goals of climate change mitigation and sustainable cities, low-carbon or carbon-negative buildings are becoming increasingly common. The buildings are planned to compensate for the embodied energy in their materials by using low-emission materials and generating emission-free energy. Embodied energy is minimized while energy generation is maximized. However, embodied energy calculations seldom consider the risk of building defects that require repairs or early replacement of building elements. As such, a building's sustainability is often calculated under the assumption that significant defects do not happen, which is known to rarely be the case. In this article, the material and monetary costs of repairing building defects are analysed. Findings suggest that certain building defects, like major roof leaks, have a significant carbon footprint. A large portion of this footprint can be attributed to the drying of the building after a leak is discovered. Building defects are common enough that the risk should not be neglected in life cycle analyses. Likewise, measures taken to reduce the risk of building defects, such as avoiding design solutions known to pose difficulties, may be considered as means to improve the sustainability of a building as well as reducing economic costs.