‹ Consumption & Efficiency

Commercial Buildings Energy Consumption Survey (CBECS)

Water Data Collection in the 2007 CBECS

CBECS 2007 - Release date: August 28, 2012

Did you know?

Select water data results are described in the accompanying report, Energy Characteristics and Energy Consumed in Large Hospital Buildings in the United States in 2007 and tabulated in 2007 CBECS Large Hospital Building List of Tables.

The 2007 round of the Commercial Buildings Energy Consumption Survey (CBECS) was the first time in the 30 year CBECS history that questions about water consumption were asked of respondents. EIA, in cooperation with the Environmental Protection Agency (EPA), added these questions to the CBECS because water and energy consumption are connected in many ways. Extracting, purifying, pumping and transporting drinking water, heating and processing water for domestic and other uses, and treating and disposing of wastewater are all activities that use energy. The California Energy Commission estimates that water has significant embedded energy content, between 2,000 and 20,000 kilowatt-hours per million gallons.1 Currently there are no nationwide estimates of water consumption in the commercial buildings sector, and the CBECS was believed to be an appropriate way to collect this data. The questions about water in the 2007 CBECS were experimental. This report discusses the ability of respondents to answer the questions.

Water Data Collection in the 2007 CBECS

At the end of the 2007 CBECS questionnaire, respondents were asked to report the total volume of water used (consumption) in 2007, how much it cost (expenditures), whether the volume was metered or estimated, and how much of the water was used outside the building. If the building used central chillers, respondents were asked the volume of water used for cooling towers.

Four questions related to water consumption were also added to a section of the questionnaire regarding miscellaneous equipment: whether the sewer flow was metered, the presence of sterilizers or autoclaves, whether the building had a landscape irrigation system, and the number of commercial ice makers.

Prior to the CBECS interview, respondents were provided with advanced materials to prepare for the interview. A worksheet with these water questions was included so the respondent could gather the information, if available.

View the full text of the water questions and the worksheet.

Ability of Respondents to Report Water Data

Water Consumption and Expenditures

Does 56 percent response represent "success"?

In 2007, among buildings that used electricity, 66 percent of respondents were able to provide electricity data for the building in the building characteristics interview.2 Collecting energy data has been one of the main focuses of the CBECS since its inception. Considering that this was the first time that water data collection had been attempted, EIA considers 10 percent below the response rate for electricity reporting to be a success.

Overall, EIA considers this pilot water data collection a success. Among the 2007 CBECS sampled building respondents that used water, 56 percent of them were able to report consumption, expenditures, or both. Table 1 shows further detail on the ability of the overall 2007 CBECS sample respondents to report these data.

Water consumption and/or expenditures reporting rates varied substantially by principal building activity, as shown in Table 2. Inpatient healthcare buildings had the highest reporting rate of, at 69.4 percent. Public order and safety, education, lodging, public assembly, food sales, and religious worship buildings also had high reporting rates, above 60 percent. Vacant commercial buildings had the lowest rate, 35.8 percent.

Water consumption and/or expenditure reporting ability did not vary significantly across Census regions. All regions reported in the 50 to 60 percent range, as shown in Table 3.

Table 1 - Ability of 2007 CBECS Sampled Building Respondents to Report Water Consumption and/or Expenditures
  Number of Sampled Buildings Percent of Sampled Buildings Percent of Sampled Buildings that Use Water
Total 4,428 100 100
Water Not Used 358 8.1
Total Reported Consumption and/or Expenditures 2,289 51.7 56.2
Reported Both Consumption and Expenditures 1,453 32.8 35.7
Reported Consumption OR Expenditures 836 18.9 20.5
Did not know Consumption and Expenditures 1,781 40.2 43.8
Table 2 - Ability of 2007 CBECS Sampled Building Respondents to Report Water Consumption and/or Expenditures Data by Principal Building Activity
      Reported Water Consumption and or Expenditures Did not know Consumption and Expenditures
  Number of Sampled Buildings Number of Sampled Buildings that Use Water Number of Sampled Buildings Percent of Sampled Buildings that Use Water Number of Sampled Buildings Percent of Sampled Buildings that Use Water
All Buildings 4,428 4,070 2,289 56.2 1,781 43.8
Inpatient Health Care 173 173 120 69.4 53 30.6
Public Order & Safety 44 43 27 62.8 16 37.2
Education 299 292 179 61.3 113 38.7
Lodging 145 144 88 61.1 56 38.9
Public Assembly 170 164 100 61.0 64 39.0
Food Sales 81 79 48 60.8 31 39.2
Religious Worship 175 172 104 60.5 68 39.5
Office 1,074 1,052 626 59.5 426 40.5
Enclosed Mall 86 85 50 58.8 35 41.2
Outpatient Health Care 131 129 75 58.1 54 41.9
Other 235 216 124 57.4 92 42.6
Service 366 324 171 52.8 153 47.2
Warehouse 696 545 274 50.3 271 49.7
Retail Other than Mall 358 346 168 48.6 178 51.4
Food Service 242 239 111 46.4 128 53.6
Vacant 153 67 24 35.8 43 64.2
Table 3 - Ability of 2007 CBECS Sampled Building Respondents to Report Water Consumption and/or Expenditures Data by Census Region
      Reported Water Consumption and or Expenditures Did not know Consumption and Expenditures
  Number of Sampled Buildings Number of Sampled Buildings that Use Water Number of Sampled Buildings Percent of Sampled Buildings that Use Water Number of Sampled Buildings Percent of Sampled Buildings that Use Water
All Buildings 4,428 4,070 2,289 56.2 1,781 43.8
Northeast 847 787 410 52.1 377 47.9
Midwest 1,102 962 572 59.5 390 40.5
South 1,793 1,669 972 58.2 697 41.8
West 686 652 335 51.4 317 48.6

Miscellaneous Water Questions

  • Sewer flow metering
    About 91 percent of respondents were able to answer whether or not their sewer flow was metered.
  • Sterilizers or autoclaves
    Over 99 percent of respondents were able to report whether or not there were sterilizers or autoclaves used in the building.
  • Landscape irrigation system
    Over 99 percent of respondents were able to report whether or not the building had a landscape irrigation system.
  • Commercial ice makers
    All buildings that used electricity (4,259 buildings) were asked whether there was refrigeration equipment present in the building. Some type of refrigeration equipment was in 81 percent of these buildings. Respondents that reported the presence of commercial refrigeration were shown a list of seven types of refrigeration and were asked which types were found in the building. In the 2007 CBECS, one of these seven types was new to the list – commercial ice makers. Of the respondents asked about refrigeration types, 98 percent of them were able to answer whether or not they had ice makers, and 94 percent of those that had ice makers were able to report the exact number.
  • Water metered/estimated
    All buildings that reported a water consumption figure were asked how the figure was determined: metered, estimated, both metered and estimated, or measured in some other way; 97 percent of the respondents were able to report how the figure was determined.
  • Outside water consumption
    All buildings that reported a water consumption figure were asked how much of the total water was used outside the building. About 81 percent of the respondents were able to report the outside water consumption figure.
  • Cooling tower water consumption
    Buildings that reported a water consumption figure and had a central chiller inside the building were asked how much of the total consumption was used for the cooling tower; 50 percent of these respondents were able to report their cooling tower consumption.

Conclusion

The collection of water consumption data in commercial buildings was experimental in the 2007 CBECS. Prior to conducting the survey, it was unknown whether many CBECS respondents would be able to report this information. Of the responding sampled buildings, 56 percent of all responding sampled buildings were able to report consumption or expenditures or both. Reporting success varied by building type, with inpatient healthcare buildings reporting at the highest rate, 69 percent.

As a result of the success of the data collection in the 2007 CBECS and the strong relationship between water and energy consumption, EIA plans to collect water data again in the 2012 CBECS, with improvements based on lessons learned from 2007. Data collection for CBECS 2012 will begin in early 2013 and EIA plans to publish the water estimates for the entire commercial buildings population in 2014.

Footnotes

1 California Energy Commission (CEC). (2006). "California Water - Energy Issues", Public Interest Energy Research (PIER) Program, Presented at the Western Region Energy - Water Needs Assessment Workshop, Salt Lake City, Utah, January 10, 2006.

2 EIA collects energy data from the suppliers in the Energy Supplier Survey when the building respondent is unable to provide it under statutory authority Section 13(b) of the Federal Energy Administration Act of 1974, P.L. 93-275, codified at 15 U.S.C. 772(b). EIA does not have statutory authority to collect water data from water suppliers.


Specific questions on this product may be directed to:

Joelle Michaels
joelle.michaels@eia.gov
Survey Manager