An Investigation of the Energy Efficiency of Traditional Buildings in the Oporto World Heritage Site

Oporto’s traditional buildings are the major contributors for shaping the World Heritage Site Despite this, and as is the case in most European historic cities, they are not individually listed and any adaptations to make them comply with current energy efficiency requirements may cause negative impacts on their authenticity and integrity. This paper aims to identify which energy efficiency improvement measures can be applied without damaging the buildings’ heritage value. For this purpose, fieldwork and simulation data of ten case studies were used. On-site results revealed that the energy consumption in Oporto’s traditional buildings was below European average and the households expressed that their home comfort sensation was overall positive. Simulations showed that introducing insulation and solar thermal panels would be ineffective in terms of energy and cost efficiency as well as comfort improvement. This study reinforces the idea that traditional buildings perform better than expected in terms of energy consumption and can be retrofitted and updated at a low-cost and with passive solutions.