As global energy systems face increasing strain from urbanization, renewable energy integration, and the push toward decarbonization, the ability to dynamically manage energy demand has become critical. Energy flexibility (EF) emerges as a key strategy to support demand-side management and enhance energy system resilience. This study presents a comprehensive systematic literature review on building energy flexibility (BEF), a key enabler of demand-side energy management and resilient urban energy systems. Employing the PRISMA methodology, Using the PRISMA methodology, 787 papers published between 2019 and 2024 were initially screened, resulting in a final set of 191 studies included for detailed analysis. The analysis reveals a dominant focus on residential buildings and electric energy systems, with load shift and demand response emerging as the most frequently implemented strategies. Grey-box models and optimization-based approaches were the most widely adopted modeling techniques, often supported by simulation tools like MATLAB and EnergyPlus. Despite growing interest in hybrid systems and real-time control, significant gaps persist in addressing flexibility at district levels, integrating non-electric energy vectors, and incorporating continuous temporal resolutions. Furthermore, the environmental and user-centric impacts remain underexplored. This review synthesizes critical insights and proposes a structured research agenda to bridge the gap between theoretical models and real-world deployment, offering strategic guidance to policymakers, energy system designers and urban planners to develop flexible, sustainable energy systems and buildings. • Reviews 191 studies on building energy flexibility from 2019–2024. • Maps modeling methods, system scales, and flexibility strategies. • Identifies dominance of grey-box models and optimization techniques. • Highlights data and methodological gaps across energy system types. • Outlines research priorities for scalable, hybrid flexibility modeling.
Hristov et al. (Sun,) studied this question.