Survey of Construction

To provide nationwide coverage of building activity, a multi-stage stratified random sample procedure was used to select approximately 900 building permit-issuing offices, and a sample of more than 70 land areas not covered by building permits. Each month, for permit-issuing places, a sample of residential building permits is selected from each of the sampled permit offices. The probability of selecting a permit is proportional to the number of units authorized by the permit. Permits for one-to-four-unit buildings are sampled at an overall rate of 1 in 50. All permits authorizing buildings with 5 or more housing units in the sampled permit offices are selected.

Data collected includes start date, completion date, sales date, sales price (single-family houses only), and physical characteristics of each housing unit, such as square footage and number of bedrooms. Reported data are for building or sales activity taking place during the applicable reference period. Monthly data collection begins the first day after the reference month and continues through the 7th working day.

Each month, for areas that do not require building permits, field representatives conduct a road canvass in each of the sampled non-permit land areas to identify the start of new buildings. All new residential buildings found are selected for the survey.

Once a permit or building is selected, a field representative contacts the owner or builder, by telephone or in person, to conduct the interview each month as necessary. Contact continues until the project is either completed or abandoned. If a single-family home is not sold by the time of completion, the project will continue to be followed until the sale occurs. Each month, interviews are required for about half of the buildings currently being followed up.