Abstract
Renovating existing buildings is crucial for reducing energy consumption and mitigating climate change. This study explores the potential of reusing reclaimed mineral wool insulation in building renovations in Norway, focusing on energy, environmental, and economic impacts. A representative Norwegian single-family house was analysed through several renovation scenarios combining existing, reclaimed, and new insulation materials, all meeting the Norwegian building code’s minimum requirements. The analysis covered operational heating demand, life cycle greenhouse gas emissions, and costs over 30 years. Results show that upgrading the building envelope can reduce heating demand by up to 74% compared to the as-built condition. Scenarios using reclaimed insulation have the lowest greenhouse gas emissions from material production and transport, as reclaimed material manufacturing emissions are excluded. However, life cycle emissions vary based on the operational energy mix: in Norway’s low-emission electricity context, material production and transport emissions are more significant, favouring reuse. In higher-emission contexts, such as Europe, operational energy emissions dominate, reducing reuse benefits. Regarding costs, while reusing insulation does not significantly reduce initial investment costs due to labour for disassembly and reinstallation, long-term savings may be possible, particularly in markets with high electricity costs. The study emphasizes the need for further research on the long-term performance of reclaimed insulation to support wider adoption. Material quality and condition are key to ensuring energy savings, environmental benefits, and cost-effectiveness, highlighting the importance of condition assessment protocols and a reliable supply chain. These findings support sustainable renovation practices and aim to shift public perception toward reuse.