The INHERIT framework offers stakeholders a tailored, standards-based approach to evaluating and improving the comfort and energy performance of historic buildings without compromising their cultural value.
Historic buildings account for a significant share of the European building stock, with a substantial proportion dating from before 1945. These buildings are architecturally and culturally significant, yet they are often exempt from the strict energy-related requirements applied to conventional buildings, owing to the risk that deep retrofit interventions pose to their historic character. At the same time, cultural heritage buildings remain in daily use, meaning that their energy performance and indoor environmental quality still need to meet acceptable standards for the people who occupy them.
To address this challenge, INHERIT proposes a holistic framework for evaluating both the energy performance and the indoor environmental quality (IEQ) of cultural heritage (CH) buildings. The assessment criteria are presented in the paper “A Holistic Framework for Evaluating Energy Performance and Indoor Environmental Quality in Cultural Heritage Buildings”, authored by the National Technical University of Athens and the University of Thessaly.
Building on the principles of the New European Bauhaus (NEB) movement – which calls for the integration of design, technology and social responsibility – and on the European Commission’s Level(s) framework for sustainable buildings, the proposed methodology brings together fourteen criteria across five thematic areas:
- Energy performance: overall and disaggregated energy intensity (heating, cooling, lighting and other critical uses), share of energy produced from renewable sources, and the Smart Readiness Indicator (SRI), including its three constituent sub-categories.
- Thermal comfort: frequency of indoor air temperature and humidity within acceptable ranges.
- Air quality: frequency of indoor CO2 concentration within acceptable limits.
- Visual comfort: frequency of illuminance within acceptable ranges.
- Acoustic comfort: frequency of indoor noise levels within acceptable limits.
The thresholds underpinning the IEQ-related criteria are drawn from the EN 16798-1:2019 standard, using its Category III (moderate expectation) limits as the default baseline, a deliberate choice that reflects the constraints of working with historic fabric, while allowing stricter Category I thresholds to be applied where particularly sensitive heritage assets need to be safeguarded.
Recognising that assessing cultural heritage buildings involves balancing multiple, often competing, objectives, the framework adopts a multi-criteria decision-making (MCDM) approach. The authors identify PROMETHEE as the most suitable method for this purpose, owing to its ability to incorporate stakeholders’ explicit preferences, handle partial rankings, support sensitivity analysis, and provide intuitive visual outputs. To determine the relative importance of each criterion, the framework further proposes the use of the Simos method, which allows decision-makers to rank criteria intuitively without requiring advanced technical expertise, an important feature given the case-specific nature of heritage conservation priorities.
By combining internationally recognised standards with a flexible, preference-based evaluation method, the framework gives energy managers, conservation specialists and public authorities a practical tool for monitoring the current condition of cultural heritage buildings, benchmarking performance, and prioritising retrofit interventions that respect historic value while improving occupant comfort and energy efficiency. The approach also contributes to building stock observatories by supplying transparent, comparable data to support the design of future energy policies and conservation measures.
Read the full paper here.