This chart is taken from the Architecture 2030 website (http://www.architecture2030.org/current_situation/building_sector.html). This organization was established by Edward Mazria in 2002. Data from the US Energy Information Administration illustrates that buildings are responsible for almost half (48%) of all energy consumption and green house gas emissions annually; globally the percentage is even greater. Seventy-six percent (76%) of all power plant-generated electricity is used just to operate buildings.
To create a US Building Sector percentage for the year 2000, the Residential buildings (operations) sector (20.4 QBtu), Commercial buildings (operations) sector (17.2 QBtu), Industrial sector - buildings operations (2.0 QBtu) and the Industrial sector - annual building construction and materials embodied energy estimate (8.57 QBtu) were combined. Total annual 2000 Building Sector consumption was 48.17 QBtu and the total annual 2000 US Energy consumption was 99.38 QBtu. Source: US Energy Information Administration (consumption numbers vary slightly depending on the EIA table used. To be conservative, Architecture 2030 rounded down).