Methodological Proposal to Resolve the Dichotomy between Improving Energy Efficiency and Preserving Heritage—Case Study: Brutalist Built Heritage

The debate about how to conduct energy interventions in built heritage remains open. At present, the various European and national regulations allow the absence of energy intervention in cases where the character of a building with recognized heritage value would be jeopardized. This situation means that heritage preservation and energy improvement are divided into two airtight and unconnected blocs. It is possible and necessary to break that dichotomy by taking steps that enable both blocs to interrelate. Based on a methodology previously proposed by the authors to regulate changes in the urban landscape due to the rehabilitation of residential building façades, as a novel aspect, this article proposes taking a further step in the methodological process. Several criteria to balance the level of energy intervention for all buildings are thus introduced, according to the urban and architectural characteristics of each building, irrespective of their use and degree of protection. It is concluded that such a balance is possible when certain indicators are used and when determined action criteria are applied. However, one of the architectural characteristics more susceptible to being affected when undertaking an energy intervention on a building’s thermal enclosure is the materiality, which becomes especially important in the case of brutalist architecture with reinforced concrete, one of its most identifying features, giving it a specific personality. That architectural movement was therefore chosen for a case study, applying the proposed methodology to three brutalist buildings in the area of San Sebastián, Spain.