Double-skin facades for thermal comfort and energy efficiency in Mediterranean climate buildings: rehabilitating vulnerable neighbourhoods

Abstract

The ongoing global energy crisis in Europe has intensified energy poverty in vulnerable households, prompting a critical examination of passive retrofit strategies for improving the habitability of obsolete social housing in southern Europe from the 1960s. Given the Mediterranean climate’s characteristics (hot summers and mild winters), these buildings possess low thermal resistance envelopes designed for heat dissipation in summer but contribute to elevated heating demands in colder months. In response to the pressing need for solutions that strike a balance between reducing energy demand and ensuring year-round comfort, this research explores diverse approaches. Drawing insights from built prototypes in Colombia and Hungary and utilizing a validated simulation model in Seville, Spain, this study investigates the feasibility of implementing a double-skin envelope on building facades and assesses the impact of thermal insulation in the air chamber. So, the research specifically aims to find an equilibrium between lowering energy demand and maintaining adequate comfort conditions, concentrating on the renovation of obsolete social housing with envelopes featuring low thermal resistance in the Mediterranean climate. Results indicate that, due to the poor thermal envelope, the influence of thermal insulation on comfort conditions and energy savings outweighs that of the double skin. Consequently, the emphasis of renovation projects for this climate should not solely concentrate on passive cooling strategies but should strive to achieve a positive balance in comfort conditions throughout the year, encompassing both warm and cold months.