Mandatory Real Estate Diagnostic: Complete List 2026

The technical diagnostic file is not an administrative formality you put together the day before signing. It is a contractual document whose absence or expiry deprives the seller or landlord of the clause excluding liability for hidden defects, and opens the door to a price reduction or cancellation of the sale. The difficulty lies less in the list of diagnostics than in two things: knowing which ones apply to your property, and monitoring validity periods that range from six months to unlimited.

What triggers the obligation

No property requires all of the diagnostics. Three parameters determine the applicable list:

• The nature of the transaction. A sale and a rental do not call for the same file. Some diagnostics are common to both, others are specific to one or the other.
• The age of the property and its installations. The year of construction determines the asbestos and lead diagnostics; the age of the gas and electrical installations determines theirs.
• The location. Termites, dry rot, natural and technological risks depend on prefectural orders and municipal zoning.

This leads to a practical rule: the list must be built property by property, never copied from a neighbouring property's file.

Diagnostics required for a sale

The energy performance diagnostic. Valid for ten years. This has become the most consequential document, because it no longer merely informs: it now determines whether a property can be rented out, and its rating has been binding since the reform that gave it enforceable legal effect.

The energy audit. This is required in addition to the energy performance diagnostic for sales of single-family homes and buildings under single ownership rated in the lowest categories. The scope is being expanded in successive stages: this is a point to check for the current year, as the timetable has been adjusted several times.

Asbestos. Required for properties whose building permit predates July 1997. A negative finding does not need to be redone; a positive finding requires periodic monitoring.

The lead exposure risk assessment. For homes built before 1949. Its validity depends on the result: unlimited if the finding is negative, only one year if it reveals lead levels above the threshold.

Gas and electrical installations. Mandatory as soon as the installation is more than fifteen years old. Valid for three years for a sale.

The risk disclosure statement. Natural, mining, technological, seismic, radon risks. Its validity is short — six months — and it is the diagnostic that most often expires between the preliminary contract and the final deed.

Termites. Only in zones designated by prefectural order, also with a six-month validity period.

Non-collective sanitation (septic systems). When the property is not connected to the public sewer network, valid for three years.

Measurement (surface area). Private floor area in a condominium falls under the Carrez law. Its validity is unlimited as long as no work changes the surface area, but an error of more than one-twentieth entitles the buyer to a price reduction.

Diagnostics required for a rental

The file is shorter, and the validity periods differ — this is the most common source of error among landlords who reuse a sale file.

• The energy performance diagnostic, valid for ten years.
• The lead assessment, whose validity for a rental is six years if positive, unlimited if negative.
• The gas and electrical installation assessments, valid for six years for a rental versus three years for a sale.
• The risk disclosure statement, always six months.
• The living area, as defined by the Boutin law, distinct from the Carrez area.

The full set is appended to the lease. This appending is not symbolic: it is what makes the file enforceable, and its absence can be argued in court. The electronic signature of a residential lease offers a concrete advantage here, by sealing the contract and its appendices into a single dated set that can be shown not to have been recomposed afterwards.

The tipping point: energy decency standards

The energy performance diagnostic has changed in nature. It no longer merely informs the buyer or tenant: an insufficient rating simply prohibits renting the property out altogether.

The ban is being phased in progressively, starting with the most energy-hungry properties, and tightening over the years to cover subsequent rating classes. As the timetable has been revised several times, the only reliable approach is to check the rule in force for the year in question rather than relying on a remembered deadline.

Two practical consequences for a landlord. First, a diagnostic close to a class boundary deserves a cross-check before any commitment is made, since a tipping point changes the property's status. Second, a diagnostic carried out under an earlier calculation method may give a different rating than one redone today: the date it was carried out matters as much as the result. This subject is covered in more detail in our article on the standards applicable to the performance diagnostic.

What is at stake with an incomplete file

The absence of a mandatory diagnostic is not simply penalised by a fine. It deprives the seller of the benefit of the clause excluding liability for hidden defects for the issue concerned. In practical terms, a buyer who later discovers a defect covered by a missing diagnostic can seek a price reduction, or even have the sale rescinded.

An expired diagnostic has the same effect as a missing one. This is why documents with short validity periods — the risk disclosure statement and the termite report, six months — must be monitored between the signing of the preliminary sale agreement and that of the final deed, a period that frequently exceeds this threshold.

Finally, the diagnostic must be carried out by a certified and insured professional. A file drawn up by an uncertified provider is unenforceable, regardless of the quality of its content.

Usage scenarios

Sale of a condominium apartment built before 1949. The file combines the Carrez measurement, the lead assessment, the asbestos assessment, the risk disclosure statement and, depending on the age of the installations, the gas and electrical assessments. This is the most comprehensive configuration.

Renting out a house built in the 1980s. Asbestos and lead are out of scope. Attention focuses on the energy rating, which determines the right to rent the property out, and on the installations if they are more than fifteen years old.

Managing a rental property portfolio. Monitoring becomes more a matter of scheduling than of one-off compliance: each property carries its own deadlines. Guidance for organising this monitoring can be found in our rental management guide, and the traceability of document handovers ties in with that of the move-in/move-out inventory.

Frequently asked questions

How long does a diagnostic remain valid? It varies from six months — risk disclosure statement, termites — to ten years for the energy performance diagnostic, with unlimited validity for a negative asbestos or lead finding. The same service can have two different validity periods depending on whether it is used for a sale or a rental.

Can a sale diagnostic be used for a rental? Not automatically. Validity periods differ, and the measurement is not the same — Carrez floor area for condominiums in a sale, living area under the Boutin law for a rental.

What happens if a diagnostic is missing from the deed? The seller loses the benefit of the clause excluding liability for hidden defects for the issue concerned. The buyer can seek a price reduction or have the sale rescinded.

Who can carry out these diagnostics? A diagnostician certified by an accredited body, holding professional liability insurance. A file drawn up by an uncertified provider is unenforceable.

Can the energy rating prevent a property from being rented out? Yes. The most energy-hungry properties are being progressively excluded from the rental market, in stages covering successive rating classes. As the timetable has changed several times, it must be checked for the current year.

Do diagnostics need to be redone after renovation work? Work affecting the surface area invalidates the measurement. Work involving insulation or heating warrants a new energy performance diagnostic, which may move the property into a different class — either better or worse.

Key takeaways

The list of mandatory diagnostics must be built property by property, based on three parameters: the nature of the transaction, the age of the building and its installations, and the location. No standard checklist exempts you from this verification.

The real operational risk is not forgetting a diagnostic, which is easy to spot, but the expiry of a short-validity document between the preliminary agreement and the final deed. And the real strategic risk lies in the energy rating, which has become a condition for operating the property rather than a mere piece of information. Both of these points deserve to be tracked by deadline, not left until the moment of signing.