Description of methodological improvements of the utility function in the BSM

This report presents methodological advancements to enhance a spatial building stock model and its associated energy assessment toolbox, with the aim of better analysing building stock decarbonization pathways and related questions of resilience and sustainability. It introduces the overall objectives, outlines the role of building stock modelling, and highlights the central importance of the utility function that represents building owners’ decision-making. The core contributions focus on improving how owner choice behaviour is modelled, addressing interactions between heating systems and building envelopes, the influence of socio-economic factors, the distinction between perceived and actual technology choices, the role of spatial constraints, and refinements to energy cost calculations to reflect evolving tariff structures. These improvements are grounded in empirical evidence from multiple data sources and enable more realistic representation of investment decisions, technology adoption, and spatial limitations. Additional methodological enhancements include refinements to parameter calibration and clearer representation of data flows between model components, ultimately enabling richer model outputs and more robust assessments of the resilience of building-related energy systems, while also outlining directions for future work.