A novel prescriptive approach for buildings’ insulation design considering embodied carbon

The reduction of energy consumption and environmental impact of buildings is critically important. Thermal insulation is highly effective in reducing energy needs. Therefore, national policies have regulated and encouraged insulation retrofits. Their environmental convenience depends on the carbon footprint of the materials used and the carbon density of the energy consumed. However, this is not usually reflected in prescriptions, and no studies have tried to formulate practical solutions for this integration. This work proposes a prescriptive approach based on Type-III declarations of materials and the carbon footprint of thermal energy to improve the environmental convenience and feasibility of retrofits. The life cycle environmental balance of thermal insulation retrofits is first investigated with a simplified analytical model. Then, the analytical model is applied to a parametric case study. The effect of natural hazards on maintenance-related emissions is also considered, an aspect quite unexplored in the literature. The results demonstrated that the impact of the embodied carbon is significant, especially considering future realistic low-carbon energy scenarios and the impact of a natural hazard on the needed maintenance. The proposed approach, conceived to be applicable in current practices, allows for a reduction of the minimum thermal resistance of the opaque envelope by up to 33% in the case of low embodied carbon materials and low carbon density heating technologies. The novel approach can still deliver energy savings of more than 60% and reduce the life cycle emissions and materials required, opening new perspectives for more sustainable and holistic regulations in the building sector.