Building Energy Use Statistics

1. Energy Use in the Building Sector: Buildings account for a significant portion of the electricity and fossil fuel use in our planet and emit an equally sizable amount of greenhouse gas (GHG) emissions. According to the World Business Council for Sustainable Development (WBCSD), buildings worldwide account for 40% of the global energy consumption.[1] Available energy use statistics by sector from Canada and the U.S. point to similar percentages with energy use in residential and commercial buildings representing 31% of total Canadian energy use and almost 42% of the U.S. energy consumption.[2] [3] Finally, the BUILD UP European web portal of energy efficiency in buildings states that buildings also account for 40% of the energy use in the European Union. [4]  

2. Building Energy Use by End-Use: Further characterization of the commercial building energy use by end use shows that 50% to 60% of the energy use is for space comfort including space heating and lighting. As shown below, the Canadian energy use statistics contained in the 2009 Energy Use Data Handbook published by Natural Resources Canada identifies space heating as the largest end-use, accounting for 50.1% of the total commercial sector energy use of 1,186 PJ.[5] Available energy use data from the U.S. is also listed below and points to similar statistics with space heating being the largest end-use in U.S. commercial buildings, accounting for 32% of the total sector energy use.[6] Lighting which accounts for an additional 11 to 22% of the total is the second largest end-use in the U.S. and the third largest in Canada. Combined, space heating and lighting account for 55 to 60% of total building energy use. 

It is worth noting that space heating is a significant component of energy use in geographic locations with more moderate climate. In fact, according to the WBCSD, heating is the largest end use in the six largest markets reviewed in their Energy Efficiency in Buildings research work.[7] In the U.S. for example, space heating is still a significant contributor in cities such as Atlanta, Georgia with ~3,000 heating degree-days (HDD65) and winter design temperature (Td) of 18°F and Las Vegas, Nevada (~2,400 HDD65 and 27°F Td). The table shown below provides an energy end-use breakdown by heating DD (HDD65) from the U.S. Commercial Energy Consumption Survey (CBECS). As shown, space heating is the largest end-use in 60% of the total U.S. commercial floor space.[8] More telling though is the fact that space heating, lighting and space cooling account for approximately 61% of the total energy use of all commercial buildings. Cooling, however is a very small end-use, accounting for 6.6% of the total U.S. commercial building energy use, yet it is frequently cited as being a large end-use.

3. Energy Use in Existing Commercial Buildings, New Buildings and Low Energy Buildings: As shown in the data presented above, the whole building energy intensity of a typical existing commercial building in the U.S. ranges from 21 ekWh/ft² (813 MJ/m².yr) in cooling-only locations to 32 ekWh/ft² (1,240 MJ/m².yr) in heating dominated regions with an overall sector average of approximately 26.6 ekWh/ft² (1,030 MJ/m².yr). Similarly, the sector average whole building energy intensity for Canadian commercial building is 43.2 ekWh/ft² (1,673 MJ/m².yr).

Further differentiation of whole building energy intensities is provided in the graphic shown below which compares the U.S. and Canadian commercial sector average building energy intensities to various vintages and efficiency levels of office buildings including low energy buildings that exhibit ultimate energy performance levels of 5 to 12 ekWh/ft² (194 to 465 MJ/m².yr).[9] [10] This range represents the lowest whole building energy intensities that have been attained based on information from multiple sources including high performance building designs monitored by the National Renewable Energy Laboratory (NREL), the best energy intensities recorded in the 2012 REALpac Energy Benchmarking Report and some notable examples of European low energy buildings. [11] [12] [13]