When historic buildings are adaptively reused for new functions, they must be heated and cooled to levels of thermal comfort their original fabric was never designed for, while conservation and adaptive-reuse principles severely restrict the interventions allowed. The source study — a post-occupancy evaluation of the Former Soldier's Residence at the Cairo Citadel, now an administrative office — poses the resulting twin challenge: how to optimize energy use for air cooling or heating so that acceptable thermal comfort and energy efficiency are achieved for inhabitants while complying with the rigid principles that protect the building's heritage value. The subsequent literature remains dominated by single-case simulation and monitoring studies: multi-objective optimization and multi-criteria decision frameworks have been demonstrated on individual heritage buildings, and the European guideline standard EN 16883 structures retrofit decision-making, but no validated general methodology exists that jointly optimizes energy, thermal comfort, and heritage-value preservation across climates and reuse functions. The problem is open.

Background

Adaptive reuse is the practice of assigning a historic building a new use — office, hotel, museum, housing — so that it remains in service rather than being abandoned or demolished. It is governed by conservation principles that are deliberately rigid: minimal intervention in historic fabric, reversibility of additions, distinguishability of new work from old, and respect for the building's authenticity and heritage value, as codified in international charters and national preservation regulations. Because most historic buildings predate modern climate control and were built for their original use, their new occupants typically require heating and cooling the original envelope and systems were never designed to deliver. Thermal comfort is assessed either by heat-balance models of the Fanger type (predicting the mean thermal-sensation vote of occupants from air temperature, radiant temperature, humidity, air speed, clothing, and activity) or by adaptive comfort models, which allow comfort temperatures to drift with the recent outdoor climate and are usually the appropriate standard for free-running or loosely conditioned buildings. Post-occupancy evaluation (POE) is the combined objective (instrumented measurement) and subjective (occupant-survey) assessment of how a building actually performs in use. The source study, a POE of the Former Soldier's Residence in the Cairo Citadel (reused as the head office of the National Organization for Urban Harmony), found exactly the conflict the field knows from other climates: improving comfort and efficiency would demand interventions that the reuse principles forbid, and its abstract poses the challenge as how to optimize the use of energy for air cooling or heating given that adaptive-reuse decisions are grounded in very specific and rigid principles. The surrounding literature frames this as an unresolved field-wide problem rather than a settled engineering task. Reviews of energy retrofit in historic buildings show that substantial efficiency and comfort gains are achievable case by case but that no universal retrofit approach exists; the European standard EN 16883 (a guideline for improving the energy performance of historic buildings) provides a multi-criteria procedure for documenting and justifying retrofit choices against heritage impact, but supplies no benchmarks, no way to resolve conflicts between criteria, and no optimization. In ordinary (non-heritage) buildings, multi-objective optimization — coupling dynamic building-energy simulation with evolutionary search to trace trade-off frontiers between energy use, comfort, and cost — is a standard technique; what is missing is its validated extension to adaptively reused heritage buildings, where the conservation side of the problem is qualitative, legally rigid, and hard to formalize as a constraint or objective.

Problem Statement

How can the use of energy for heating and cooling in adaptively reused historic buildings be optimized so that acceptable thermal comfort and energy efficiency are achieved for the inhabitants while the rigid principles of heritage conservation and adaptive reuse that protect the building's heritage value are still complied with? Energy efficiency, thermal comfort, and heritage compliance are coupled criteria of one objective, not separable deliverables: an answer that improves energy use at the cost of conservation, or comfort at the cost of either, does not answer the question. The research target is a general methodology — one in which the heritage-conservation principles are made explicit, the comfort and energy objectives are quantified, and the resulting trade-offs are traced — whose validity extends beyond a single case (across multiple buildings, climates, or reuse functions), since the source itself presents its single-building post-occupancy evaluation as one domain of a multi-domain general problem; determining which method class is best suited to the problem is itself part of the question. The question retains the source's full generality; no restriction of building type, climate, function, or admissible measure is intended, and generality means the methodology's reusability beyond the single case that motivates it rather than its instantiation over the whole domain.

References

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