Economic evaluation of the energy consumption and thermal passive performance of Portuguese dwellings

•Energy performance of an entire neighbourhood (17 dwellings) in Portugal.•How specific changes in constructive elements lead to important energy consumption.•Environmental evaluation was made at the design stage.•Thermal study and an energy (electricity-based) cost analysis for different scenarios.•A comparison is made if the neighbourhood is built in three different climate regions. The aim of the present work was to assess the energy performance of 17 dwellings to be constructed in a neighbourhood in the south of Portugal (town of Loulé). The goal was to study how specific changes in constructive elements lead to important energy consumption if the entire neighbourhood is affected. The assessment was based on the Portuguese insulation regulation and on Portuguese domestic energy consumption habits. The choice of the constructive technology for the envelopes was based on its environmental evaluation via two methods: Emergy Evaluation and Energy Analysis. Two dwellings were chosen as case-studies in order to carry out a thermal study and an energy (electricity-based) cost analysis for different scenarios. These scenarios were set considering different constructive elements with influence on the thermal performance of the dwellings. Additionally, the previous analyses were carried out for the two selected dwellings considering two additional Portuguese regions: centre-south (Lisbon) and Northeast (Bragança). For these particular dwelling typologies and in the framework of the Portuguese regulation, the overall conclusions indicate that the constructive elements whose changes lead to higher energy efficiency are the scenarios that include the shading system and the type of openings, though with different importance regarding each region.