The survey is based on the housing stock on 1 January 2008. Holiday homes, residential units and special purpose residential building are not included. In order to establish whether the dwellings are inhabited, Statistics Netherlands’ housing register was linked to the municipal population register. The population register contains people registered in a municipality on this date. Both registers comprise address data. With the aid of this link it was possible to determine whether a dwelling in the housing register was inhabited by someone in the population register. The register contains homes that are intended for permanent residence.