Valuing a property with no public comparable: the method when there is no listing

On a publicly listed property, the price is judged by comparison: other listings, a time on market, a history of reductions. On a confidential property, none of that exists, and that is the real trade-off of off-market access. This page gives the replacement method, alongside our reference page on off-market access.

Start from what was paid, not what is asked

Since 2019 the tax administration has published, as open data, the property value declarations database, fed by notarised deeds and updated twice a year. For each transfer for value it gives the address, the date, the price, the floor area and the type of property. It is the only public source that says what was paid.

On a property with no listing, it is read at three successive scales. The building first: a unit sold eighteen months ago on the same staircase is the strongest comparable that exists. The street next, over three years, setting aside floor areas far from the one that interests you. The district last, for the trend, never for the point.

Two limits apply and they should be known. The database covers neither Alsace-Moselle nor Mayotte, which fall under a separate land registration regime. And it ignores the property’s condition: two flats at the same address can differ by thirty per cent depending on floor level, aspect and works.

Correct the reference price with documented differences

A price per square metre drawn from the database is an average. It is corrected, and each correction should rest on a document rather than an impression.

• Floor level and lift: a ground floor on the street and a fourth floor with a lift do not belong to the same market, in the same building.
• Aspect and view, to be recorded on site at the time of the viewing, with the hour and orientation noted.
• The energy rating: since letting the most energy-hungry ratings was banned, a poor performer taken on by an investor carries a works budget and a deadline, and that can be quantified.
• Works voted at a general meeting and not yet called in, readable in the minutes the seller must hand over.
• A floor area shortfall: in a co-ownership, a private area more than five per cent below the one stated opens the proportionate price-reduction claim under article 46 of the Act of 10 July 1965, for one year from the deed. Better to establish it beforehand.

Use indexes for the trend, never for the value

The quarterly indexes of the notaries and of the national statistics institute say which way the market is going, not what a property is worth. They serve one precise and useful purpose: updating an old comparable. A unit sold twenty months earlier in the same building remains the best starting point, provided it is placed within the segment’s movement since that date.

They also answer a frequent seller’s argument, that of a price fixed on the memory of a higher market. A public series puts a figure against a conviction, and that is all it is asked to do.

Have it costed by those with no interest in the sale

Two third parties value without being party to the transaction, and their opinion arrives before signature.

The lender first. A bank financing an acquisition has the property valued, and it lends on the basis of its own valuation. A costing below the agreed price forces you to fill the gap with a larger deposit or to renegotiate; either way, the information is free and it arrives in time. It is often the only quantified counterweight a buyer has on a property with no comparable, and one more reason to have processed financing before the first viewing.

The property valuer next, for atypical properties: a townhouse, an open floor, a prestige property, an address with no series of comparable sales. They give a reasoned opinion of value, with their method and comparables, which can be used in a negotiation. On a standard flat in a building that has seen several recent sales, the expense is not justified.

What the absence of a comparable does not change

It changes neither the seller’s obligations nor the statutory deadlines. The technical survey file, the co-ownership documents and the ten days of withdrawal apply identically, as our page on the deadlines from offer to deed recalls. Nor does it excuse checking that the property really is off-market, which our checklist for spotting a fake off-market sets out: a property listed elsewhere for six months has, for its part, every comparable in the world.

You have a confidential property in view and want its value costed before making an offer: the personal study offered by French Realty gathers the transfers at the address, the documented differences and the co-ownership documents, with your dedicated contact.