A comparative benchmarking study of multi-storey residential buildings in two periods of energy saving efforts: the 1980s and the 2010s

The heat consumption in comparable multi-storey residential buildings can vary significantly from building to building, just as the consumption in a building varies from year to year. The former typically relates to year of erection, level of insulation and realised energy improvements, composition, caretaker skill and enthusiasm and similar factors, while the latter usually relates to weather (temperature, wind, and sun). Therefore, it can be difficult for the housing association, the building administration and the building owner to assess whether a specific building performs satisfactorily, what the energy saving potential is of specific energy improvements and the value of optimising operational control parameters. In 1990, Technological Institute in Denmark analysed 23,000 Danish dwellings divided into 92 typical multi-storey buildings. This study included measurement data for the 1970s and the years after the energy crises and the first tightening of the building regulation’s thermal requirements. The study showed significant reductions in energy consumption. In an ongoing study of the heating consumption in Danish multi-storey residential buildings, 18,000 dwellings with a total heated area of 1,085,000 m², is being analysed. This study includes measurement data from the last 10-20 years and thereby cover a period with an increasing focus on environmental and climate impacts of energy consumption. During these two decades, the heat consumption has increased and decreased, but the consumption is more or less the same today as it was in 2000. This paper presents a comparative study of the two sets of measurement data and thereby energy saving efforts. In addition, the results feed into a web-based benchmarking tool using key indicators like monthly energy consumption, energy signatures and annual carbon emission. The purpose of the benchmarking tool is also to predict the effects of energy saving measures and to estimate pre- and rebound effects.