Multi-objective evaluation of different retrofitting scenarios for a typical Greek building

Abstract

In this study, multiple retrofitting scenarios of a typical Greek house were investigated. These scenarios encompass the addition of insulation to the building’s external walls and roof, a green roof construction, the use of high-quality windows and the installation of an efficient heat pump. The aforementioned techniques were simulated separately and in combination with the use of the DesignBuilder software, on an annual basis, for the city of Athens, Greece. The pivotal innovation of this work lays in the energy simulation and the comprehensive comparison of the 34 retrofitting scenarios according to a multi-objective evaluation procedure. An additional novelty was the investigation of the energy impact of each renovation action when applied separately. The goal of the multi-objective evaluation procedure was to determine the optimum renovation case, for maximizing the energy savings and minimizing the life cycle cost. According to the results, the optimum retrofitting case included the installation of insulation to the building’s external surface and the heat pump retrofitting. The optimum scenario resulted in a 41.7% reduction in the building’s heating loads and a 14.9% reduction in its cooling loads. Finally, the primary energy savings were 66.1% and the life cycle cost analysis showed 6,645 € lifespan savings.