Energy rehabilitation of Portuguese residential building stock through its transformation into NZEB

Abstract

The first global oil crisis, led the European Union to start the necessary procedures in order to control and reduce the energy consumption of buildings. In Europe the energy consumption of residential buildings increased since 1990 until 2003 1.3% per year and it is expected that, by 2050, the energy consumption of buildings will have increased by 40%. According to the EPBD-recast all member states should adopt the necessary measures so that buildings become highly efficient - nearly Zero Energy Buildings (nZEB’s). Nevertheless, quantitative standards are not appointed, so each member state should establish the minimum requirements for energy performance in buildings attending to the local conditions. However before establishing these requirements it is necessary to evaluate the building stock and its energy efficiency. As most of the Portuguese residential buildings are old and degraded an opportunity arises for the energy rehabilitation of the building stock, implementing EPBD-recast principles, making it more energy efficient and comfortable. The aim of this study was to describe the current conditions of the building stock in order to identify whether there are suitable conditions for energy rehabilitation of buildings. The analysis performed showed that although there are a significant potential for building energy rehabilitation, there are also some constraints, namely the lack of credit and loans financing of banks.