Where the figures come from
Every price BRIVEO publishes comes from DVF (Demandes de valeurs foncières), the register of property transfers published as open data by the French tax authority, the DGFiP. It records sales that were actually signed before a notary, not asking prices.
The database we hold covers sales recorded from 1 January 2023 to 31 December 2025. That end date is our vintage: we read it from the table itself rather than writing it down, so it follows the next release on its own and can never quietly become false.
The vintage we hold is the second half of 2025, and we loaded it on 24 April 2026. The DGFiP publishes every six months, so a gap between those two dates is normal; we show it rather than hide it, because a figure whose age is unknown cannot be checked.
One sale is one observation, never one line
DVF does not store one line per sale: it stores one line per LOT. A single transaction carrying a block of 200 flats produces 200 lines, and each one repeats the TOTAL value of the transaction while carrying only its own floor area.
Dividing line by line therefore manufactures a false price per lot, and a block sale manufactures as many false points as it has lots, enough to become the majority and carry the median away. We aggregate per transaction before computing anything.
What we publish, and the threshold below which we publish nothing
For each commune we publish the median price per square metre, the interquartile range, and the number of sales the figure rests on. Nothing else.
Below 25 sales over twelve months, we publish no price at all. A median computed on a handful of sales is not a market median, it is an impression, and publishing it would be worse than saying nothing.
We never publish a minimum or a maximum. An extreme value IS an identifiable transaction, and republishing it falls under article R112 A-3 of the French Book of Tax Procedures.
Which commune a sale belongs to
A commune is identified by its INSEE code, never by its name: French commune names are not unique. Saint-Denis exists both in Seine-Saint-Denis and on Réunion Island, Grigny in two different departments, Merville in two more.
Its postal code is the one carried by the majority of its own sales, not the largest of them. A large commune has several, and the largest is often a fringe code shared with its neighbour.
What we do not cover, and why
DVF does not cover Bas-Rhin (67), Haut-Rhin (68) and Moselle (57), which come under the Alsace-Moselle land book system, nor Mayotte (976). We publish no price per square metre for those departments. BRIVEO does operate there, but a valuation rests on departmental references rather than comparable local sales, and it is announced as indicative.
Sale volumes are counted over the twelve months preceding the computation. Since the database stops at 31 December 2025, that window is in practice shorter than twelve months for the most recent computations. We state it here rather than let the label suggest otherwise.
The confidence level of a valuation, and what it measures
A property valuation starts from the comparable DVF sales retained within a radius around the property, a radius adapted to the density of the postal code. Outlying sales are discarded before any computation, using an interquartile filter. The range shown is the interval between the first and third quartile of the price per square metre of those sales, multiplied by the floor area of the property. The central price is the median.
The confidence level (Indicative, Approximate, Fair, Reliable) measures one thing, the number of comparable sales retained. It is not a percentage of accuracy, and we publish none, because nothing in our computation measures one. The number of sales required for each level is lower when the point designates the exact parcel of the property, because the sales gathered are then those of its immediate surroundings.
The level is never raised by a correction, it can only go down. It is capped at Fair when the postal code covers several communes and the commune is not specified, lowered by one step when the local price references or the available DVF sales are old, capped at Fair in the overseas departments DVF covers, and capped at Indicative in the departments DVF does not cover.
Reusing our figures
Every page shows its source, the period covered, the number of sales and the date the figure was computed. You may quote them by naming BRIVEO and the DVF/DGFiP source.
The raw data is public and free: anyone can recompute what we publish.