Parametrization of variables affecting the whole life carbon performance of nearly zero energy residential building renovation

This research investigates the integration of life cycle impact assessment (LCIA) and building performance simulation (BPS) to evaluate the whole-life carbon performance of residential building renovations. A representative post-World War II single-family house in Belgium is used to analyze six renovation scenarios that combine petrochemical and bio-based materials. By coupling LCIA with BPS, the study captures both embodied and operational greenhouse gas (GHG) emissions across the building lifecycle, emphasizing the tradeoffs inherent in materials selection and renovation design. The adoption of a dynamic building performance simulation approach enables the accounting of variations in the electricity mix and future energy demand patterns. Results demonstrate that ultra-low energy renovations can reduce total emissions (embodied and operational) by 70 % compared to the base case non-renovated building, reaching a value of 11.7 kgCO₂e/(m^2.y). However, even this scenario does not meet the Danish total GHG emissions threshold of 8.2 kgCO₂e/(m^2.y). Sensitivity analyses highlight the influence of parameters like heat pump efficiency, airtightness, and photovoltaic system performance. Scenarios using bio-based insulation achieve up to a 7 % reduction in embodied emissions compared to those using petrochemical materials. This innovative approach provides a comprehensive framework to balance operational and embodied emissions, offering actionable insights for designers and policymakers to align with European zero-carbon targets while addressing the complexities of renovating existing building stocks.