A Pareto-Based Multi-Criteria Framework for Evaluating Refurbishment Packages for Energy Flexibility

Abstract

Renovation of existing residential buildings is crucial for achieving energy efficiency and climate neutrality, yet practical constraints such as cost, construction-related disruption, and user acceptance often limit the implementation of deep refurbishment strategies. Furthermore, the potential for demand-side energy flexibility remains largely untapped, despite its importance for integrating variable renewable energy sources. This paper presents a holistic, user-centered evaluation framework for stepwise refurbishment packages that balances energy performance, ecological impact, economic cost, construction effort, and user acceptance. The framework operationalizes a multi-criteria decision-making approach, combining quantitative indicators, ordinal expert assessments, and user-specific weighting into a Composite Performance Index, called Pareto-Index (PI). Heterogeneous indicators are normalized, aggregated to overarching criteria, and weighted according to individual preferences, enabling transparent comparison of refurbishment measures across technical, ecological, economic, and behavioural dimensions. Measures are organized hierarchically into thematic clusters to capture typical implementation contexts and interdependencies. Based on cluster-wise PI scores and psychometrically adjusted thresholds, the framework supports the formation of refurbishment packages that achieve substantial benefits with comparatively limited effort, reflecting asymmetric perceptions of effort and gain. The approach is implemented in the interactive LevelUp tool, which guides users through structured decision-making and package selection. The paper demonstrates the methodology on representative Austrian residential building types, highlighting how stepwise, preference-aligned renovation can unlock energy flexibility and sustainability gains in a realistic and scalable manner. The framework provides a practical decision support tool for policymakers, planners, and building owners, bridging technical analysis and user-centered considerations for energy-efficient refurbishment.