Abstract
Roof leakages are a frequent source of building damage, but their cli-mate impacts remain poorly quantified. This study assesses the greenhouse gas emissions associated with representative leakage scenarios in common Norwegian roof constructions, including ventilated pitched roofs and compact flat roofs with different configurations. Three damage scenarios are analysed: (1) early detection with localised and limited damage, (2) late detection leading to moisture pene-tration into the insulation layer, and (3) long-term undetected leakage resulting in extensive deterioration of roof coverings and underlying components. For each scenario, the analysis includes emissions from material replacement, waste man-agement, and energy consumption for mechanical drying. The results demonstrate a strong increase in emissions with increasing damage severity. Early detection scenarios show limited climate impact due to minor material replacement and short drying periods, whereas late detection scenarios require insulation renewal and prolonged drying, substantially increasing emissions. In the most severe long-term scenario, total emissions for a 100 m2 compact flat roof exceed 9,000 kg CO2-eq, driven by extensive reconstruction following prolonged moisture exposure and constrained drying conditions. To provide a broader context, the scenario-based analysis is complemented by an exploratory national-level assessment based on available statistics and building databases, showing the potential climate signif-icance of roof leakages at the national scale. The findings highlight that proac-tive maintenance, timely leak identification and climate-robust roof design can significantly reduce climate impacts, underscoring the importance of preventive maintenance strategies for a resilient Norwegian building stock.