By: 

CBECS Team

April 2023 | Webinar

2018 Commercial Buildings Energy 

Consumption Survey (CBECS): 

Highlights and Methods
Outline

• Introduction

• 2018 CBECS highlights

• Survey methods

• Using CBECS data

• Q&A

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Introduction
CBECS is...

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• The Commercial Buildings Energy Consumption Survey 

• The only independent, statistically representative source of nationallevel data on the characteristics and energy use of commercial 

buildings

• A data collection that produces a snapshot of the commercial building 

stock and their energy use for a reference year, most recently for 

2018 

• Required by Congress, conducted periodically 

since 1979 (2018 was the 11th CBECS)

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CBECS is not...

• An energy audit

• A rating system or certification program

• A walk through the building (for example, ASHRAE Level 1 audit)

• A database of building energy performance data

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What is a commercial 

building?

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• Commercial 

– More than 50% of floorspace is devoted to activities that are neither residential, industrial, nor 

agricultural

• Building 

– A structure intended for human access that is totally enclosed by walls that extend from the 

foundation to the roof

– CBECS covers all commercial buildings larger than 1,000 square feet, with a few exclusions.

• Building type

– Determined by the principal activity or function 

that occupies the most floorspace in a building

Visit Building Type Definitions on 

the CBECS web page to learn more 

about principal building activities.
• CBECS data are used to:

– Forecast or project energy consumption, including our Annual Energy Outlook

– Set energy use targets for benchmarking, including ENERGY STAR

– Design policies and programs, including building energy codes

– Conduct academic research

– Inform business decisions

• The periodic, detailed snapshots of U.S. commercial buildings are widely used to 

re-baseline a variety of analyses.

• Data from 2018 are pre-pandemic; changes that persist will be reflected in the 

next CBECS.

Final 2018 CBECS results refresh our nation’s understanding 

of how commercial buildings use energy

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2018 CBECS Results
Commercial buildings grew larger, outpacing growth in energy 

consumption

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• The estimated 5.9 million U.S. 

commercial buildings in 2018 had 96 

billion square feet of floorspace and 

consumed 6.8 quadrillion British 

thermal units (quads) of energy.

• From the first CBECS in 1979 to the 

2018 CBECS, commercial floorspace 

has increased 89% while the number 

of buildings increased 59%.

• During the same period, consumption 

of all major fuels increased only 17%.

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Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

Energy consumption, number, and floorspace of commercial buildings, 1979–2018

quadrillion British thermal units (quads), number of buildings (millions), and billion square feet
Larger buildings were fewer in number but accounted for more 

floorspace, energy consumption, and expenditures than smaller buildings 

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Number of buildings, square footage, and energy consumption by square footage category, 2018

share of total

1,001 to 5,000 square feet

5,001 to 100,000 square feet

Over 100,000 square feet

• Large buildings (over 100,000 square feet) accounted for more than one-third of total floorspace, energy 

consumption, and expenditures but were only 2% of commercial buildings.

• Almost half of the commercial buildings were small (1,001 to 5,000 square feet), but used only 8% of the 

energy consumed.

5.9 million

number of 

buildings

96.4 billion 

total floorspace

in square feet

6,787 

trillion Btu 

total energy 

consumption

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

Note: Btu = British thermal units

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$141.2

billion 

total energy 

expenditures
U.S. commercial buildings continued to consume less energy per 

square foot of floorspace in 2018

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• From 2012 to 2018, the major 

fuels energy intensity, or energy 

consumption per square foot, 

decreased by 12%.

– Electricity intensity 

decreased by 14%.

– Natural gas intensity 

decreased by 11%. 

• Energy efficient building often 

have lower energy intensities.

Energy intensity by select fuels, 1979–2018

thousand British thermal units per square foot

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

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Warehouse and storage, office, and service buildings were the most 

common building types

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Percentage of commercial buildings and floorspace by principal building activity, 2018

• Warehouse and storage, office, and service buildings together accounted for 48% of all commercial 

buildings and 42% of total commercial building floorspace.

• The number of warehouse and storage buildings also increased more than 25% from 2012 to 2018, 

along with service, public assembly, and lodging buildings.

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

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Energy intensity decreased in several building types from 2012 

to 2018

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Major fuels intensity by principal building activity, 2012–2018

thousand British thermal units per square foot

• Inpatient health care buildings had the 

largest decrease in energy intensity from 

2012 to 2018. 

• Outpatient health care, office, and 

education buildings also showed 

statistically significant decreases in 

energy intensity.

• None of the building types had a 

statistically significant increases in 

energy intensity. 

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

* Change is statistically significant at the 10% significance level.

** Change is statistically significant at the 5% significance level.

Note: Building Type Definitions on the CBECS web page provides more information about the principal 

building activities.

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Space heating accounted for close to one-third of end-use 

consumption in 2018

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• Space heating was the most common 

end use in commercial buildings. About 

2,167 trillion British thermal units of 

energy was consumed for space 

heating.

• Other, ventilation, and lighting each 

accounted for 10% or more of total 

energy consumption. 

Major fuels consumption by end use, 2018

share of total

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

Note: Btu = British thermal units

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Energy intensity for heating and cooling commercial buildings 

varied by climate zone

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Note: Climate affects energy consumption for the end uses selected. 

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

Major fuels energy intensity by climate zone and space-conditioning end uses, 2018

thousand British thermal units per square foot

• Buildings in the coldest climates were nearly five times more energy 

intensive to heat than buildings in the hottest climates.

• Conversely, cooling energy intensity was higher in warmer climates.

Cold or very cold

Cool

Mixed mild

Warm

Hot or very hot

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Data source: ANSI/ASHRAE, Standard 169-2021, Climatic Data for Building 

Design Standards

Note: Adapted with permission from Figure A‐2, Climate zones for United 

States counties, ANSI/ASHRAE Standard 169‐2021, Climatic Data for 

Building Design Standards, © 2021 ASHRAE.

Cold or very cold

Cool

Mixed mild

Warm

Hot or very hot
Survey Methodology
Overview of the CBECS survey process

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Because no comprehensive list of U.S. 

buildings exists, EIA builds survey frames

• Area frame 

– Randomly select small, geographic areas

– Within them, list and stratify all commercial buildings in those 

areas

– Randomly select buildings within strata

• List frames

– Supplemental lists that ensure adequate representation of 

special buildings 

– Include hospitals, government buildings, college/universities, 

airports, or other large buildings 

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Note: PSU = primary sampling unit
Virtual listing method added in the 2018 CBECS

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• Created area frame using 

satellite imagery and GIS tools 

• Replaced on-the-ground listing 

in most areas

• Provided many benefits 

– 3% improvement in coverage 

compared with field listing

– More than 50% reduction in listing 

labor hours

– No travel costs
During the first phase of data collection, building owners 

and managers completed the Buildings Survey

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• In-person or telephone interview conducted by a trained interviewer or selfadministered web questionnaire 

– New for 2018, 44% of building respondents completed the survey by web

• Respondents included: 

– Building operations, maintenance, and engineering

– Property managers

– Company managers and administration

• Data collected for approximately 9 months

• Average completion time for a CBECS questionnaire was 45 minutes

• Voluntary survey

– Building and business owners

– Energy and environmental personnel

– Other people associated with a building
Numerous CBECS questionnaire changes were made for 

2018 to reflect changes in buildings and data user needs

• Questionnaire design process included:

– Reviewing content from 2012 CBECS

– Adding and dropping questions based on quality of prior responses and current building technologies

– Soliciting data user input

– Pretesting most of the new or substantially revised questions

• For example, we added questions on electric vehicle (EV) charging stations.

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Percentage of commercial buildings with EV charging stations 

by square footage category, 2018

Percentage of commercial buildings with EV charging stations 

by select principal building activity, 2018

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

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During the second phase of data collection, energy 

suppliers completed the Energy Suppliers Survey (ESS)

• Follow-up with energy suppliers for buildings that completed the Buildings Survey 

– 16 months of energy usage and costs covering calendar year 2018

– Supplements annual consumption collected in the Buildings Survey

• Approximate numbers of unique suppliers contacted: 

– 350 electricity

– 180 natural gas

– 110 heating oil

– 20 district energy

• Suppliers receive building address and energy account number(s) when available

• Data collected for approximately 7 months

• Mandatory survey

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Modeling used to estimate energy consumption by 

10 end uses

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• Engineering-based statistical model fills in for missing energy 

consumption and disaggregates total energy

• Survey characteristics and energy data used, along with information from other 

sources (for example, weather, technology efficiencies, etc.)

Total 

energy 

use

ENERGY

SOURCE

Space

heating

Space 

cooling

Ventilation

Water 

heating

Lighting

Cooking

Refrigeration

Computing

Office 

equipment

Other

Electricity X X X X X X X X X X

Natural gas X X X X

Fuel oil X X X X

District heat X X X X
For example, end-use modeling reflected changes in 

commercial building lighting characteristics

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Lighting equipment used in commercial buildings by bulb type, 2018

percentage of buildings

Data source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey

Note: More than one bulb type may apply. All changes from 2012 to 2018 were statistically significant at the 5% significance level. 

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• From 2012 to 2018, only 

LED lighting equipment 

use increased 

• Aside from LED, all other 

bulb types decreased in 

usage

standard 

fluorescent
Using CBECS Data
• Key products:

– Data tables with data quality indicators (71 tables)

– Public use microdata (6,436 buildings)

• Data available for:

• CBECS data provided for statistical purposes

– Data protected by Confidential Information Protection and Statistical Efficiency Act (CIPSEA)

– We do not disclose information that could potentially identify a particular responding building

EIA has published all final 2018 CBECS data

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– Building size, age, and structure

– Building activity 

– Census region and division

– Ownership and occupancy 

– Weekly operating hours

– Number of workers

– Energy sources and their end uses

– Heating and cooling equipment

– Other energy-related equipment 

– Annual energy use and cost data, plus 

end-use estimates for electricity, 

natural gas, fuel oil, and district heat

– Reports with data highlights

– Today in Energy articles

– Methodology and research
You can use CBECS data several different ways

• Copy charts and slides for your own presentation and reports

– Over 50 pre-made visualizations

– Available in PDF and PowerPoint formats

• Use pre-calculated estimates in your own research and analysis

– Over 70 Excel data tables with estimates and associated relative standard errors (RSEs)

• Create your own estimates with the public use microdata file

– Data files available in CSV and SAS formats

– User’s Guide provides instructions and examples for Excel, SAS, and R users

– Z variables are included to flag whether values were imputed

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Tips and tricks for using CBECS data

• Be careful about making inferences from small sample sizes

– We did not publish estimates with fewer than 20 buildings in the sample

• Don’t forget the weights

– The variable FINALWT shows how many buildings in the country each sampled case represents; tables and 

reports use this final weight for population-representative statistics

• Use the relative standard errors (RSEs)

– CBECS sample design allows for calculation of sampling errors for point estimates 

– We published RSEs in Excel data tables and withheld estimates with RSE greater than 50% 

– We recommend use of RSEs to understand the statistical significance of the difference between two statistics

• Consider how CBECS provides a snapshot in time, not time-series data

– We summarize key methodology and questionnaire changes between survey cycles

• Cite CBECS and let your audience know how you used our data

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Additional CBECS information

• 2018 data tables and microdata

https://www.eia.gov/consumption/commercial/data/2018/

• 2018 building characteristics report

https://www.eia.gov/consumption/commercial/data/2018/pdf/CBECS_2018_Building_Characteristics_Flipbook.pdf

• 2018 consumption and expenditures report

https://www.eia.gov/consumption/commercial/data/2018/pdf/CBECS%202018%20CE%20Release%202%20Flipbook.pdf

• CBECS methodology

https://www.eia.gov/consumption/commercial/data/2018/index.php?view=methodology

• CBECS terminology

https://www.eia.gov/consumption/commercial/terminology.php

• CBECS building type definitions

https://www.eia.gov/consumption/commercial/building-type-definitions.php

• Frequently asked questions (FAQs)

https://www.eia.gov/consumption/commercial/faq.php

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For more information

U.S. Energy Information Administration homepage | www.eia.gov

Commercial Buildings Energy Consumption Survey | www.eia.gov/cbecs

Today in Energy | www.eia.gov/todayinenergy

Contact us | eiainfoconsumption&efficiency@eia.gov

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Questions?