Purpose - Integrating sustainability considerations into valuation practices is essential for promoting sustainable real estate investments. However, a comprehensive understanding of how sustainability factors impact the value of real estate assets is required. This study addresses the growing importance of renewable energy and the underutilized potential of rooftops by proposing an innovative framework for the valuation of roofs when used for renewable energy production.

Design/methodology/approach - This study uses the concepts of residual value analysis and Highest and Best Use methodology, adapting them to create a new framework for rooftop valuation.

Findings - The value of a roof can be determined based on their energy generation capability, where the conditions for enhanced energy harvesting potential distinct a higher value to the host asset. This removes the hurdle for investors to use rooftops for renewable energy investments.

Originality - The novelty of this study lies in using the Highest and Best Use methodology in the valuation of roofs. To the best of our knowledge, no explicit valuation of roofs has been done in the context of renewable energy production.

Practical implications- This study contributes to innovative valuation methodologies by incorporating sustainable measures. Social implications - Social implications include the evaluation of third-party investments in renewable energy on rooftops. This could lead to increased investments and higher renewable energy production, thereby lowering energy costs and enhancing the energy supply's reliability.

The concept of value has been central to economic thought for centuries; the idea of what makes something valuable shapes how we exchange, produce, invest, and measure well-being. Neoclassical traditions have dominated the contemporary economic framework, privileging financial value as the primary metric of worth. This emphasis on quantifiability, reinforced by positivist methodologies, has marginalised broader considerations of multiple values and incommensurability. Real estate valuation perfectly embodies and exemplifies these tensions. This disjuncture between theory and practice reflects a broader issue within economics: the persistence of an overly narrow understanding of value. In response to these challenges–ranging from sustainability commitments to shifting societal priorities–we turn to a historical narrative of value theories to examine how foundational assumptions about value shape economic thought, resource allocation, and societal priorities. Recent studies point to a growing dissatisfaction with existing valuation models along with a shifting value paradigm: one that increasingly recognises multiple forms of values, the limits of commensurability, and the influence of social and ecological considerations on the practice of appraisal.

This paper systematically analyzes the effect of energy efficiency on transacted rental and capital values of Dutch retail property assets from 2015–2021. Prior research on Energy Performance Certification (EPC) and energy premiums consistently showed a pricing effect, but recent investigations reveal inconclusive results, particularly when considering non-residential properties. Leveraging a unique dataset of 1015 lease transactions and 478 sale transactions, this study provides one of the first estimates of how EPC labels impact retail value. We utilize ordinary least squares (OLS) regression, considering characteristic retail determinants such as footfall, catchment area type, and retail type, among others. This study finds a premium of 11 percent for rental transactions with Label C or higher on a price per square meter basis. Capital premiums for energy-efficient transactions are more marginal and complex, particularly when accounting for data limitations such as geographic distribution. The nexus between sustainability and financial benefits incentivizes investors and policymakers to embrace energy-efficient measures. Pioneering spatial analyses of EPCs in the retail sector, this paper offers insights for informed policy-making amid geographic variations. In the era of transparency, this research provides empirical evidence to drive responsible investments in energy-efficient retail, shifting from risk management to stakeholder benefits and improved capital efficiency.