Valuing a property in France: Patrim, DVF and median

The tax office’s Patrim service

The impots.gouv.fr website presents the “Rechercher des transactions immobilières” service, available in the espace Finances publiques, as a tool that “helps you estimate the value of your property”. It is used in particular:

• if you are selling or buying a property;
• for an inheritance declaration or a gift;
• to calculate the IFI (impôt sur la fortune immobilière, property wealth tax);
• during a tax audit, a compulsory purchase or the calculation of housing benefits.

The service is free. Once logged in, it lists the sales made over the chosen period and area, with cadastral references, address, type of property, floor area and construction period; “only sales that genuinely reflect market prices are displayed” (impots.gouv.fr). Prospective sellers and buyers have had access since 2 May 2017, under the loi pour une République numérique (Digital Republic Act) (impots.gouv.fr).

Two limits. The information obtained is for your personal use only (livre des procédures fiscales (Tax Procedures Code), art. L107 B, cited by impots.gouv.fr). And the data exclude Haut-Rhin, Bas-Rhin, Moselle and Mayotte. For the IFI, service-public.gouv.fr also refers to the “Patrim online service” to estimate the market value of a property.

The DVF open-data files

The DVF dataset, produced by the DGFiP, “shows the property transactions that took place over the last five years”, based on notarial deeds and cadastral information (data.gouv.fr). The annual files, in text format with the ”|” separator, can be read in a spreadsheet.

Sources: data.gouv.fr; DGFiP DVF guide and FAQ.

The latest year is therefore always incomplete: the October update only publishes the first half of the current year, and the year is only complete the following April (DVF FAQ). Re-use of the files must not make it possible to re-identify individuals (data.gouv.fr).

Reading a DVF line correctly

The valeur foncière (property value) is the price declared in the deed. According to the DGFiP guide, it includes agency fees paid by the seller and any VAT; it excludes agency fees paid by the buyer, frais de notaire (notary’s fees and purchase costs) and the value of any furniture stated in the deed.

Three pitfalls emerge from the guide:

1. One sale, several lines. When a sale covers several units, the file has one line per unit, and “the price [is] then repeated on each line”. Adding up or dividing without grouping distorts the price per square metre.
2. Two floor areas. The surface réelle bâtie (actual built floor area) is measured at floor level between the walls, excluding outbuildings; the surface Carrez (legally measured floor area in a co-owned building) is only included where it appears in the deed, unit by unit (five units at most per line).
3. No description. The description in the notarial deed is not included: neither the condition of the property, nor the floor, nor any works.

If your own sale appears with an incorrect floor area, it is the last floor area declared to the land tax services that is used; the DVF FAQ explains how to correct it with a déclaration foncière (property declaration).

How to read a median

According to Insee, if a distribution is ranked in order, “the median divides that distribution into two parts of equal size”: half the values are below it, half above. The mean, on the other hand, is pulled by high values, even if there are few of them, and uncertainty about extreme values “carries over to the mean but does not affect the median”, which is “from this point of view a more reliable indicator”.

Applied to property sales, this gives a simple method:

• Compare like with like: same type of property, same area, recent period.
• Group the lines of a single sale before calculating a price per square metre (DVF guide).
• Count the sales: a median calculated on a handful of transactions moves a great deal from one sale to the next.
• Adjust afterwards for condition, floor, outdoor space or the DPE (energy performance certificate), which DVF does not describe.

A median places the market; it does not set the price of a particular property. The impots.gouv.fr website points this out: for a precise estimate, the property’s own characteristics must be taken into account, “under your own responsibility”, and possibly with advice from a professional.

Which professional to consult

The agent immobilier (estate agent) weighs comparable sales against the particular features of the property. The notaire (the public official who drafts property deeds) is involved in inheritances and gifts, where the value of the property must be declared (impots.gouv.fr). The diagnostiqueur (property surveyor) produces the DPE, which carries weight in the comparison, and the géomètre-expert (chartered land surveyor) measures the surface Carrez of a unit or the boundaries of a plot.