Evaluation of indoor environment and energy performance of dwellings in heritage buildings. The case of hot summers in historic cities in Mediterranean Europe

Abstract

he potential benefits for making the historic buildings of heritage cities non-polluting and energy efficient have only recently stirred the interest of researchers and policy makers in facing the necessary challenges. In southern Europe, most of these buildings are residential and are mainly listed at low grades of protection, allowing for significant transformation. This article quantitatively evaluates the indoor environment and energy performance of the residential heritage building stock under the severe summer conditions characteristic of the Mediterranean climate zone. The historic centre of Seville (Andalusia, Spain) is used as a case study. Three dwellings located in representative listed buildings within its conservation area were monitored and analysed taking occupant behaviour into account. The findings show that many dwellings may lack thermal comfort conditions, which cannot always be guaranteed by passive strategies alone. In addition, these buildings are more polluting than recently constructed ones because they depend entirely for their energy supply on the public electricity grid. Interestingly, in most cases reducing the mechanical cooling demand would not require intrusive physical interventions, but would largely rely on suitable window shading and nightly natural ventilation when outdoor conditions allow.