Social Housing Retrofit in a Climate Change Context: A Case Study in Beira Interior, Portugal

Global climate change effects on development and sustainability are currently growing. Many of the planet’s climates present temperature increases, with the Iberian Peninsula in Europe considered as a hotspot. Action in public social housing buildings is highly considered, as a large portion was built before the introduction of thermal regulations, presents poor thermal performance and has users with low resources, representing a health-related concern. This study addresses the climatic sensitivity of a representative case study dwelling regarding the impact of constructive retrofit measures in the building envelope on improving thermal performance for heat conditions, conducted for the Beira Interior region, Portugal. Resorting to a calibrated numerical model, dynamic thermal simulations for current, future and extreme climate scenarios were performed. The resulting indoor temperatures were assessed regarding indoor thermal discomfort and overheating. The results show that the combined effect of regulation-compliant envelope measures, reinforced insulation and higher ventilation achieves considerable thermal comfort improvement, while only investing in high thermal insulation thickness achieves no substantial benefits. Controlled ventilation strategies can be highly relevant for retrofitted buildings, also due to constraints related to occupancy influence or possible thermal insulation limited effects. Heat-related discomfort is an issue, although smoother heat conditions require caution due to cool discomfort.