Energy Efficiency versus Heritage—Proposal for a Replicable Prototype to Maintain the Architectural Values of Buildings in Energy Improvement Interventions on Facades: The Case of the Expansion of San Sebastián

Abstract

The implementation of energy efficiency improvements in facades, such as ventilated facades or External Thermal Insulation Composite Systems (ETICS), is leading to a widespread modification of these structures. The lack of appropriate regulations to curb the destruction of the built heritage, particularly in historical centers, has been identified. In response to this issue, a project has been developed to create a prototype for determining regulations for facade interventions. The Design Science Research Methodology (DSRM) has been employed in the development of the prototype, which has been tested in a case study of the ensemble formed by the Cortázar and Oriental expansion areas in San Sebastián. The initial prototype has been outlined, corrected, and improved in an iterative process, resulting in a final prototype that enables a faster, more rigorous, and efficient understanding, characterization, classification, study, and definition of intervention criteria, measuring the vulnerability of buildings to these interventions quantitatively. In this study, the vulnerability is defined as the risk that a facade will alter the characteristics of its architectural style and distort the reading of streetscapes that belong to a period with a clearly defined character. The case study results have been compiled into intervention criteria sheets for each of the studied buildings. This material has been presented to the relevant public authorities, with the hope that it may lead to a modification of current legislation, thereby helping to curb the loss of architectural heritage identity.