Documentation on IRIS-based sub-municipal databases

The sub-municipal results of the population census are proposed in the form of databases based on ISIS statistical block groups. The IRIS is the basic scale for standard sub-municipal publication. It is sometimes referred to as the “IRIS district”.

Dernière mise à jour le : 07/02/2017

Database content

The sub-municipal databases cover all the IRIS of those municipalities that are broken down into IRIS, whether the said municipalities have more than or less than 10,000 inhabitants. They also contain data on the municipal level for those municipalities that are not divided into IRIS, in order to cover the whole territory.

There are three types of IRIS :

  • residential IRIS: their population is between 1,800 and 5,000 inhabitants. They are homogenous in terms of types of dwelling and their boundaries follow the main boundary lines within the urban fabric (main roads, railway lines, waterways, etc.);
  • business IRIS: they comprise about 1,000 employees and have at least twice as many salaried jobs as their resident population;
  • other IRIS: these are large specific areas having a large surface area and low populations (theme parks, ports, forests, etc.).

Among the IRIS, 92% are residential IRIS, 5% business IRIS and 3% other IRIS.

The IRIS databases are organised into five themes:

  • Activity of Residents (ACT)
  • Qualifications - Training (FOR)
  • Couples - Families - Households (FAM)
  • Dwellings (LOG)
  • Population (POP)

The data detail level and organisation of the databases are close to those for the key figures.

The “Employment – Labour Force” theme is absent because data on workplaces is not processed at the sub-municipal level in the census.

Geography and territorial modifications

  • The data for year n is presented in the geographical boundaries (municipalities and IRIS) in force on 1st January n+2.
  • An indicator identifies those IRIS that have undergone modifications since the 1999 census. Almost all IRIS have kept the same boundaries as in 1999. For these IRIS, the results of the two censuses are therefore comparable as long as account is taken of any changes of concept there might have been in the new census.