Effects of individual metering and charging of heating and domestic hot water on energy consumption of buildings in temperate climates

Individual metering and charging of heat and domestic hot water is one of the possibilities for reducing the energy consumption in existing multifamily buildings and, with this aim in mind, the EU-directive 2012/27/EU enforced the installation of individual heat consumption meters. Even though some experimental evaluation of energy savings that may be achieved in multifamily buildings with individual metering & charging systems can be found in the literature, the majority of these research pieces are focused on case studies or taking into consideration conditions related to cold climates, and there is still a lack of studies focused on evaluating its effects in more temperate climates that can be also found in Europe. Thus, in this paper, the potential of individual metering and charging of heat and hot water for saving energy in residential buildings in temperate climates is evaluated and quantified. To do so, a literature review on implementation of this system is carried out and presented firstly to get a better understanding of its implications on energy consumption in buildings. Afterwards, heating and hot water consumption data collected in a multifamily building where individual metering and charging system was implemented is evaluated in detail. With the aim of quantifying its effect on heating and hot water consumption, data corresponding to four complete heating seasons (two heating seasons prior to its implementation, and the two first heating seasons after implementing it) have been evaluated in detail, following a specific method described in the paper. Results show that individual metering and charging has brought a reduction of normalized energy consumption of 15-20% during the first two years after implementing it, and simple payback periods are around 10 years. These results confirm that individual metering and charging affects directly on user behaviour encouraging inhabitants to change their habits to reduce their energy consumption, and this effect is significant even in European temperate climates, such as the evaluated case study shows.