The use of data from the population registers as well as the Federal Buildings and Dwellings Register allows two important basic statistics, STATPOP (Population and Households statistics) and the BDS (Buildings and Dwellings statistic) to be produced. Even though the survey and the processing of the data are subject to strict quality standards, it is possible that they may contain errors. These include coverage errors which arise either through omission (undercoverage) or through double entries as well as the faulty attribution of units (overcoverage) to the reference sample.
A special survey was created to assess the coverage and the quality of the two statistics mentioned. This consists of a nationwide examination of the situation with regard to buildings, dwellings and persons in almost 500 randomly selected areas. In each of these areas, interviewers recorded the total stock of buildings and dwellings. They also asked questions of residents who were prepared to participate in a short interview. Households could also participate in the survey by internet or telephone.
The survey lasted from 2 May to 6 July 2013. The survey shows that the information in the registers is generally of high quality. The statistics based on this information are, therefore, extremely reliable.
More detailed information can be found in the following document.