Promomoting cost-effective energy retrofits through improved energy labelling

Abstract

Global energy consumption is projected to increase by 48% in 2040 compared to 2012. A more detailed analysis of the distribution of energy consumption calls attention to the fact that the building sector is responsible for up to 40% of our energy and resource consumption in both developed and developing countries, and up to 30% of all energy related greenhouse gas emissions. Due to their life cycle, which is expected to be several decades, a significant number of residential buildings will need to improve their energy performance in order to effectively reduce energy consumption and greenhouse gas emissions. More than 40% of Europe's residential buildings have inefficient energy conservation measures because they were built in the 1960s. Moreover, between 1961-1990 the housing stock doubled. By improving energy efficiency in domestic buildings, many benefits can be achieved, such as reduced operating costs, increased indoor environmental quality, user satisfaction and labour productivity. Two important measures to reduce energy consumption and lessen the effect of global warming are the Energy Performance of Buildings Directives (EPBD) and the Energy Efficiency Directive (EED). The main measure concerning the renovation of residential buildings is the establishment of a certification system for the energy performance of buildings which will include recommendations for the optimal or cost-effective improvement of the energy performance of a building or building unit. The most common model used to draw up the list of recommendations that accompanies the energy certificate refers to an automatic list. This is based on standard measures according to the type of building, without considering the actual energy consumption. Examples of these measures include increased insulation, replacement of windows and the use of heat pumps. According to different sources, the list of energy measures is often of little practical use. This is because energy certifiers do not prepare the measures for each specific building, nor do they suggest sensible costs or a chronological order for the implementation of such measures. To address this problem, this research proposes the development of a tool within the framework of the certification system, which will allow the generation of tailor-made recommendations. To this end, the study was developed in four collaborative stages. The first two stages established the basis for what needs to be improved in the certification system. Compiling a literature review, state of the art, interviews and evaluation of certification tools were the main tasks. The third stage of the research explored different techniques that could be used to formulate recommendations. Tools for obtaining geometrical models of buildings were tested and measurements of physical properties relevant to energy consumption were carried out. Finally, according to the results obtained in the previous tasks, a methodology for building evaluation was proposed, which included the use of current technologies with long-term benefits. The results show that it is possible to generate tailor-made recommendations, through real data, with reliable benefits and costs, thereby benefitting all stakeholders involved in the certification process.