Investigating the use of sustainable technologies in existing buildings for energy efficiency

The overall energy efficiency of existing buildings may be improved by the installation of sustainable technologies (STs). This paper investigates STs adopted to improve energy consumption, and identifies which class of technology has been mostly used to improve energy efficiency. To achieve this aim, existing buildings were evaluated on the basis of the type of STs installed during retrofitting to achieve energy efficiency. The research approach is a survey of professionals in the construction industry. A questionnaire was designed based upon literature and current available information on the various sustainable technologies used to improve energy performance of existing building through renovation actions. Through the survey, various STs installed in various types of building were recorded and analysed. The results show that close to 80% of the STs installed during retrofitting are those targeting the lighting and control systems, energy efficient insulation systems for old buildings, sensors, energy management systems and smart meters. The rest are double glazing, natural ventilation, energy efficient fans, energy efficient hot water systems, and water efficient systems. However, less than 10% targeted the building façade, ventilation, and air conditioning (HVAC) and solar systems