ings in the United States, and it is administered in two data-collection stages: a Building Characteristics Survey and an Energy Suppliers Survey. During the first stage of the data collection, interviewers visit the buildings selected into the sample and ask a representative of the building, such as the building’s owner, manager, or other knowledgeable person to complete the survey. During the second stage of the data collection, the energy suppliers of buildings that were not able to provide adequate information in the first stage are contacted to obtain actual usage and expenditure data from the supplier’s records.
There is little comprehensive information about the stock of commercial buildings in the United States, and EIA indicated that the lack of a comprehensive national list of commercial buildings or another suitable source from which to select a sample of buildings to interview is one of the major challenges for the CBECS data collection. Because no complete list of buildings is available to use as a sampling frame, EIA builds a new area probability sampling frame for the CBECS on a decennial basis. The frame is based on field listings of commercial buildings within specified geographic areas. This sampling frame is updated between each data collection. However, field listings are resource intensive and relying on sources that are not comprehensive for updating the sampling frame leads to coverage problems.
The CBECS sample design has undergone numerous revisions over the years, as EIA has attempted to address the cost and coverage issues, but most rounds of the CBECS have relied on a combination of an area frame and a list frame, based on existing lists of commercial buildings from a variety of sources and added at the second stage of the area frame sample. The primary sampling units have been counties or groups of counties, within which smaller geographic areas were randomly selected. All commercial buildings were listed and stratified within these smaller areas, and then a sample of buildings was randomly selected from each stratum. This approach was supplemented with information from existing building lists from other sources to ensure adequate representation of buildings that were of special interest because of their size or type of primary activity.
For the 2007 administration of the CBECS, the 2003 sampling frame had to be updated. At the recommendation of the data collection contractor, the National Opinion Research Center (NORC), the update was based on a U.S. Postal Service (USPS) Delivery Sequence File (DSF) purchased