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Keep each DVF transaction tied to the commune identity applicable on its transaction date, then map it to a clearly declared target geography. France’s commune boundaries and names change; replacing historical labels with today’s commune name can make a time series misleading. INSEE’s annual Code officiel géographique (COG), historical commune records and passage tables provide the official resources for tracing those changes.
Choose the geography your price series is meant to represent
There is no single required way to harmonize commune geography for DVF price analysis. Decide whether the analysis should preserve the commune units that existed when transactions occurred or express all observations in a later, fixed geography. That choice determines whether predecessor communes are kept separate or combined after a merger.
| Approach | What it represents | Key consideration |
|---|---|---|
| Historical commune geography | Transactions grouped using the commune units relevant to their dates. | Commune units may change, so a location’s time series can split or end when an administrative change occurs. |
| Fixed later geography | Transactions mapped to a selected later geography, such as current communes. | Several predecessor communes may need to be combined. Document the mapping and how unmatched or ambiguous records are treated. |
INSEE’s passage tables are the official starting point for correspondence between geographic vintages; they do not prescribe a particular DVF price-analysis method. State the target geography and the date or vintage it represents so readers can interpret the resulting series.
Use dated commune history instead of treating names as identifiers
A commune name is useful for checking and presenting results, but it should not be treated as a stable identity across the whole time series. Preserve the source commune code and label as they appear in the transaction’s release, along with the transaction date. Then use official commune history to identify relevant changes, including name changes, creations, disappearances and department changes.
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INSEE’s historical commune record covers those types of changes since 1943. Its page refers to the COG as of 1 January 2026. The COG page provides annual vintages from 1999 through 2026 and describes historical commune code-name pairs since 2021; that page was last updated 24 February 2026. INSEE: Code officiel géographique and INSEE: Historical commune records.
Map across vintages with INSEE correspondence tables
Use the COG passage tables to align commune geography across vintages. INSEE describes these tables as mapping communes existing since 1 January 2003 to the latest available geography and provides annual correspondence. The geographic-administration page was published 4 March 2025. INSEE: Geographic administration and passage tables.
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For a many-to-one change, retain the predecessor identities in the working data and aggregate only when producing results for the selected target geography. Record which predecessors were combined. If a correspondence is ambiguous or absent, report that status rather than silently assigning the record to a convenient current commune.
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Verify the specific DVF release before writing joins
Do not assume that a field name, code format, join key or period of coverage applies to every DVF download. The reviewed official DVF interface allows selection by commune and mutation date, but that interface evidence does not establish the complete schema or coverage of a particular downloadable release. Check the documentation for the exact release you use before specifying implementation steps. Official DVF interface.
- Record the input: note the DVF release or vintage and the transaction-date interval being analyzed.
- Inspect its documentation: confirm the actual commune fields, their definitions and formats, and the release’s period coverage.
- Preserve the original values: keep the source commune code and label with the transaction date rather than overwriting them with a current name.
- Choose and document a COG target: use historical commune records to identify events and passage tables to map between vintages.
- Review the mapped output: identify predecessor communes combined, unresolved correspondences, transaction counts and date coverage under the chosen geography.
Check whether the mapping changes what readers can compare
Compare the output under historical units with the output under the selected fixed geography when that distinction matters to the question. Report transaction counts and time coverage after mapping, and make many-to-one mergers visible. These checks help readers distinguish an administrative-unit change from a change in observed transactions.
A commune’s merger or renaming is not, by itself, evidence that property prices rose or fell. The available evidence does not establish a general effect size for administrative changes on DVF price analysis; assess the transaction data using the geography and method you have declared.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Keep tax and cadastral rules separate from price-series methods
DGFiP material on territorial boundary changes concerns fiscal treatment, not a method for harmonizing observed DVF transaction prices. Its cited property-tax guidance says valuations established for each former commune may remain unchanged until the next general revision under the rules it discusses. That does not determine how an analyst should group transaction prices. DGFiP: Territorial boundary changes and property-tax valuations.
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1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsLikewise, cadastral section identifiers are not interchangeable with commune identifiers. DGFiP notes that sections of attached communes are prefixed with the commune’s INSEE code to avoid confusion in cadastral section identification, with exceptions. DGFiP: Cadastral sections of attached communes.
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