Travail de fin d'études / Projet de fin d'études : Developing a building energy model for a nearly zero-energy semi-detached home

Abstract

Europe has committed to reducing greenhouse gas emissions by 55% by 2030 and achieving carbon neutrality by 2050. The building sector, as one of the largest contributors to energy consumption and CO ₂ emissions, plays a central role in meeting these targets. The recast 2020 Energy Performance of Buildings Directive (EPBD) requires all new buildings to meet Nearly Zero Energy Building (NZEB) standards by 2030, with increasingly stringent carbon limits expected for the exis ting building stock. This study focuses on developing a building energy simulation model that incorporates Belgium’s time-varying electricity carbon intensity to identify strategies for reducing energy demand and operational carbon emissions in a nearly ze ro-energy semi- detached home. The analysis is based on post-occupancy measurements and field surveys. The case study building, constructed after 2000, was documented via drone photogrammetry to produce a high-fidelity 3D digital model and a physical 3D-printed maquette. A detailed energy model was developed and calibrated in DesignBuilder/EnergyPlus using four years of monitored gas, electricity, and indoor environmental data from the Sustainable Building Design (SBD) Lab (2021 –2024). The validated model was used to evaluate multiple low-carbon technology configurations, with operational carbon performance calculated using annual, monthly, daily, and hourly grid carbon intensity factors. Results indicate that operational carbon reductions exceeding 80% can be achieved through a combination of electrification, rooftop photovoltaics, and moderate battery storage, particularly when system operation is aligned with low-carbon periods of the electricity grid. The analysis also shows that using annual average carbon factors can underestimate actual emissions by up to 50% compared to hourly calculations, emphasizing the importance of time- sensitive carbon accounting in building performance assessments. The findings provide a practical and replicable framework for int egrating temporal carbon intensity into building energy modeling, offering guidance for policymakers, designers, and homeowners seeking to accelerate decarbonization and reduce energy demand in the Belgian residential sector.