Evaluation of Energy Efficiency Measures and Use of a Photovoltaic Thermal System with Insulation for a Historical Single-Story Residential Building Located in Gontenschwil, Switzerland

Energy has always been a matter of debate around the world. Today, energy crisis is one of the most important global issues, particularly in Europe. The increasing price of energy sources caused by the Russian invasion of Ukraine and its economic consequences are inevitable [1]. The recent situation requires significant changes in energy resource consumption. Household and business buildings and their construction sectors, when combined, account for approximately one third of total global energy consumption and approximately 15% of direct CO2 emissions among all energy consuming sectors [2]. Buildings are responsible for approximately 40% of the European Union’s energy consumption [3]; therefore, reducing energy consumption and carbon footprint levels must be considered as soon as possible [4]. To reach these aims, many regulations, strategies, and directives have been deployed to reduce energy consumption by promoting energy efficiency initiatives [5]. To date, energy system plans and models are generally implemented to analyze various renewable energy and energy efficiency measures. The main aim is to comprehend the amounts of primary energy resources that can be reduced and their environmental benefits [6]. Many studies have been conducted in different regions and energy sectors across the world. Among these studies, building initiatives have attracted the interest of many researchers [7]. Recent trends show that due to rapid urbanization around the world, more than 70% of the total population will live in cities by 2050. Obviously, cities feature many buildings that are undeniably responsible for high amounts of energy consumption and carbon emissions [8].