The geographical reference of the database in evolution 2018-2023 is the Official geographic code (COG) of the active municipalities on January 1, 2023, both for the 2023 data and for those of 2018.

The data is produced throughout France, except for Mayotte.

In municipalities divided into arrondissements (Paris, Lyon and Marseille), the data is produced at the level of the arrondissement. The district is then considered as a commune.

For various reasons, two vintages of BPE are not immediately comparable. Analysing changes in the number, density and accessibility of facilities in a given area from the BPE has long been strongly discouraged. Indeed, it is particularly complex to assess in comparisons over time what is a change in nomenclature, a change in source, a change in quality of the source or, finally, a real evolution in the services and facilities accessible in the field.

However, in order to meet the needs of the users of the BPE, assessments are carried out each year to determine the conditions under which it is possible to use the BPE in evolution.

Each year, the publication of BPE in evolution:

• covers two years spaced at a five-year interval;
• concerns a limited number of types of facilities considered, over the period concerned, to be the most stable from the point of view of their definition, layout, construction, etc. ;
• excludes types of facilities related to National Education (in the field of education, only facilities related to agricultural education is disseminated in evolution);
• is carried out in the geography of the most recent year.

Thus, the BPE in evolution 2018-2023 is in geography 2023.

The BPE in evolution 2018-2023 covers 149 types of facilities and one million items of facilities.

The BPE in evolution contains a subset of equipment types from the BPE as at 1 January 2023. Some of these types of facilities are accompanied by usage reservations. These may be due to various factors:

• changes in the number of facilities linked to their reclassification as another type of facility (for example, supermarkets becoming hypermarkets following a change of APE code);
• the registration procedures used in the original administrative file (for example, the registration of doctors practising at multiple addresses may vary from one département to another);
• the national expansion of a system (for example, the number of temporary accommodation centres will increase sharply in 2019 and 2020, following a government decision), etc.

For any analysis of trends, counts should be avoided at the finest geographical levels. Instead, a presence/absence indicator should be published for the area in question. A good knowledge of the terrain is necessary before any analysis and interpretation.