The U.S. Energy Information Administration has posted preliminary results from its periodic Commercial Buildings Energy Consumption survey. Data for the project were collected in 2012 and detailed analyses of energy consumption will be released beginning next spring. The project includes buildings >1,000 sf that devote more than half of their floorspace to activity that is not residential, manufacturing, industrial, or agricultural.
The preliminary results from the Commercial Buildings Energy Consumption Survey (CBECS) show that there were 5.6 million commercial buildings in the United States in 2012, comprising 87.4 billion square feet of floorspace. This represents a 14% increase in the number of buildings and a 22% increase in floorspace since 2003, the last year for which CBECS results are available.
The preliminary data can be found in this summary table of building counts and total square footage by building size category, principal building activity, year of construction category, Census region, and Census division. The first tab provides the estimates; the second tab on the table provides relative standard errors (RSEs) for the estimates.
For comparison, there is a similar summary table from the 2003 CBECS. Other file formats for the same table can be accessed from the 2003 CBECS data page.
The size, use, vintage, and geographic region of a building are among the key determinants that influence its energy use. Subsequent releases will show more detailed characteristics and crosstabulations among key categories. This is the first release of many reports and data releases expected for the 2012 CBECS; these preliminary tables provide a first look at the building stock and the attributes that drive commercial energy use.
Trends – 1979 to 2012: Growth in building size outpaces increases in building stock
Since the first CBECS was conducted in 1979 to the current 2012 CBECS, the number of buildings has increased from 3.8 million to 5.6 million, and the amount of commercial floorspace has increased from 51 billion to 87 billion square feet.

HOW DOES EIA PRODUCE RELIABLE RESULTS FROM A SAMPLE SURVEY?
The CBECS is a national sample survey. See How Were Buildings Selected for the 2012 CBECS? for an overview of the sampling process. After the sample was selected, preparations for the interviewing phase began. In April 2013, about 250 field interviewers were trained to visit buildings across the United States and recruit respondents knowledgeable about energy use in the buildings. After recruiting a respondent at a building, the field interviewer’s job was to conduct an interview on a laptop computer asking questions about the building’s structure, use, energy equipment, and energy use. Between April and November 2013, interviews were conducted in-person or by telephone at over 6,500 buildings nationwide. Because every building had a chance to be selected and that chance is known, a sample weight can be assigned to each case. The resulting dataset is representative of the entire U.S. commercial building population.
Principal building activities: The most prevalent building types account for the majority of the total buildings and floorspace, while the building types with the largest average buildings are less common in the building stock
The commercial building sector is characterized by diversity. The 2012 survey identified more than 100 subcategories of building activity, which are aggregated into the 14 principal building activities shown in the summary table and in the figures below. CBECS includes buildings as small and singular in activity as a freestanding bank or fast food restaurant, to buildings as large and complex as an office building with hundreds of tenants or a major airport terminal. CBECS also includes vacant buildings; some vacant buildings use energy, either for maintenance purposes or because a small amount of space is still used in the building1.
Among the general building activities, lodging, education, and health care are the largest buildings, on average. The health care category's average is greatly affected by the size of inpatient health care buildings (i.e., hospitals), which have an average size of 247,700 square feet per building, compared to outpatient health care buildings, which have an average size of 12,100 square feet.

Figure 4 tracks changes in the building stock over the past 10 years by comparing the number of buildings for each principal building activity from 2003 to 2012. The highest percent of growth was in vacant buildings and other types of buildings, which includes buildings such as airplane hangars, laboratories and data centers. Warehouses, food service buildings, public assembly, and office buildings also increased between 2003 and 2012, while food sales buildings (e.g., grocery and convenience stores) showed a decrease,2 and mercantile (retail and malls) showed a decrease, although it is not statistically significant. Because CBECS is a sample survey, each estimate has sampling error associated with it, which should be considered when comparing estimates. See What is an RSE? and Estimation of Standard Errors for more information.

Size of buildings: Although there are relatively few very large buildings (over 100,000 square feet of floorspace), they account for more than one-third of total commercial building floorspace
Commercial buildings are often depicted showing a skyline of towering buildings. However, the vast majority of commercial buildings are relatively small. Just less than half of buildings are 5,000 square feet in size or smaller, and nearly three-fourths are 10,000 square feet or smaller. The median building size is 5,100 square feet (i.e., half the buildings are larger than this and half are smaller), while the average size is 15,700 square feet. The average is larger than the median because of the influence of a small number of very large buildings; buildings over 100,000 square feet make up only about 2% of the building count but about 35% of the total floorspace.

Year constructed: The commercial building stock is middle-aged, and newer buildings are larger than older ones
Commercial buildings remain in use for many decades. Although about 12% of commercial buildings (comprising 14% of commercial floorspace) were built in the past 10 years, the commercial building stock is still fairly old, with about half of all buildings constructed at least 35 years ago. However, in the existing building stock, there are more buildings built in the 2000s than buildings built prior to 1946.

Newer buildings tend to be larger than older buildings. The average building size for those constructed before 1960 is 12,000 square feet; buildings constructed between 1960 and 1999 average 16,300 square feet; and buildings constructed in the 2000s average 19,100 square feet. The differences between these average building sizes are statistically significant.

Census region and division (see map): The South has the most commercial buildings, but the Northeast has the largest commercial buildings
The South Census region, the most populous of the four Census regions, has the largest percentage of commercial buildings and commercial floorspace, with about 40% of both total buildings and floorspace. The Midwest and West regions each account for more than one-fifth of commercial buildings and floorspace.

Buildings in the Northeast region are, on average, 4,000 to 5,000 square feet larger than buildings in the other regions. The Northeast region includes the Middle Atlantic division (New York, Pennsylvania, and New Jersey), where buildings average 22,400 square feet.

Footnote
1 CBECS principal building activity is defined as the activity occupying the most floorspace. Respondents are first asked if there is one activity that occupies 75% or more of the floorspace. If not, CBECS collects the top three building activities and their corresponding percents and the principal activity is assigned as the one comprising the most floorspace.
2 Estimates for number of food sales buildings can be somewhat misleading because grocery stores and convenience stores are often part of strip malls and therefore included in the "Enclosed and strip malls" category in CBECS. "Enclosed and strip malls" is a subcategory of "Mercantile" and is shown in the summary table.
Specific questions on this product may be directed to Joelle Michaels.
Related Stories
Office Buildings | Feb 9, 2023
Post-Covid Manhattan office market rebound gaining momentum
Office workers in Manhattan continue to return to their workplaces in sufficient numbers for many of their employers to maintain or expand their footprint in the city, according to a survey of more than 140 major Manhattan office employers conducted in January by The Partnership for New York City.
Giants 400 | Feb 9, 2023
New Giants 400 download: Get the complete at-a-glance 2022 Giants 400 rankings in Excel
See how your architecture, engineering, or construction firm stacks up against the nation's AEC Giants. For more than 45 years, the editors of Building Design+Construction have surveyed the largest AEC firms in the U.S./Canada to create the annual Giants 400 report. This year, a record 519 firms participated in the Giants 400 report. The final report includes 137 rankings across 25 building sectors and specialty categories.
University Buildings | Feb 8, 2023
STEM-focused Kettering University opens Stantec-designed Learning Commons
In Flint, Mich., Kettering University opened its new $63 million Learning Commons, designed by Stantec. The new facility will support collaboration, ideation, and digital technology for the STEM-focused higher learning institution.
Sustainability | Feb 8, 2023
A wind energy system—without the blades—can be placed on commercial building rooftops
Aeromine Technologies’ bladeless system captures and amplifies a building’s airflow like airfoils on a race car.
Codes and Standards | Feb 8, 2023
GSA releases draft of federal low embodied carbon material standards
The General Services Administration recently released a document that outlines standards for low embodied carbon materials and products to be used on federal construction projects.
University Buildings | Feb 7, 2023
Kansas City University's Center for Medical Education Innovation can adapt to changes in medical curriculum
The Center for Medical Education Innovation (CMEI) at Kansas City University was designed to adapt to changes in medical curriculum and pedagogy. The project program supported the mission of training leaders in osteopathic medicine with a state-of-the-art facility that leverages active-learning and simulation-based training.
Multifamily Housing | Feb 7, 2023
Multifamily housing rents flat in January, developers remain optimistic
Multifamily rents were flat in January 2023 as a strong jobs report indicated that fears of a significant economic recession may be overblown. U.S. asking rents averaged $1,701, unchanged from the prior month, according to the latest Yardi Matrix National Multifamily Report.
Giants 400 | Feb 6, 2023
2022 Reconstruction Sector Giants: Top architecture, engineering, and construction firms in the U.S. building reconstruction and renovation sector
Gensler, Stantec, IPS, Alfa Tech, STO Building Group, and Turner Construction top BD+C's rankings of the nation's largest reconstruction sector architecture, engineering, and construction firms, as reported in the 2022 Giants 400 Report.
Giants 400 | Feb 6, 2023
2022 Transit Facility Giants: Top architecture, engineering, and construction firms in the U.S. transit facility sector
Walsh Group, Skanska USA, HDR, Perkins and Will, and AECOM top BD+C's rankings of the nation's largest transit facility sector architecture, engineering, and construction firms, as reported in the 2022 Giants 400 Report.
Giants 400 | Feb 6, 2023
2022 Telecommunications Facility Sector Giants: Top architecture, engineering, and construction firms in the U.S. telecommunications facility sector
AECOM, Alfa Tech, Kraus-Anderson, and Stantec head BD+C's rankings of the nation's largest telecommunications facility sector architecture, engineering, and construction firms, as reported in the 2022 Giants 400 Report.