Cost optimality and nZEB target in the renovation of Portuguese building stock - Rainha Dona Leonor neighborhood case study

Abstract

Improving energy efficiency in existing buildings is a great challenge. These buildings have their own limitations related with their design, location and function. To study the possibilities of cost-effectively improve the thermal performance of these buildings and increase the chances of reaching the nearly zero energy (nZEB) target, one building of Rainha Dona Leonor neighborhood has been analyzed. The purpose of the study was to find the most cost-effective renovation solution for this case study and assess in what way this solution contributes to reaching the nZEB target. With this work it was possible to understand that the energy performance of this kind of buildings can be firstly improved through renovation measures applied to the envelope but, above a certain level, changing the existing equipment and the energy source become more cost-effective.