Which diagnostics are mandatory to let a property?

At a minimum the DPE and the habitable floor area; depending on the home, these are joined by the ERP, lead (before 1949), asbestos (before 1997), electricity and gas (installations more than 15 years old) and the noise diagnostic in the areas concerned.

Who pays for letting diagnostics?

The landlord. The diagnostics must be carried out by a certified diagnostician and their cost is deductible from property income under the régime réel.

How long is a diagnostic valid?

It depends: ten years for the DPE, six months for the ERP, six years for electricity and gas in a letting. A diagnostic that has expired at signing is treated as missing.

Mandatory diagnostics to let a property: the technical diagnostic file

Updated on July 16, 2026 · 7 min read

Before letting a home, the landlord must gather several technical diagnostics and attach them to the lease: this is the technical diagnostic file (dossier de diagnostic technique, DDT). These documents inform the tenant about the condition of the home and are legally binding. Forgetting one, or supplying an out-of-date diagnostic, makes the landlord liable.

The technical diagnostic file (DDT)

The DDT brings together all the mandatory diagnostics to be given to the tenant. It is attached to the lease at signing and, for certain items, as early as the letting advert. The tenant cannot waive it: this information underpins their informed consent.

The exact list depends on the nature and age of the home, its location and its heating system. Not every property requires every diagnostic.

The list of diagnostics to provide

Depending on the home, the DDT may include:

the DPE (energy performance certificate), required as early as the advert and legally binding;
the état des risques et pollutions (ERP, statement of risks and pollution), in the areas concerned;
the constat de risque d’exposition au plomb (CREP, lead exposure risk report), for homes built before 1949;
the asbestos diagnostic, for buildings whose permit predates July 1997;
the condition of the internal electrical and gas installation, when it is more than 15 years old;
the habitable floor area (loi Boutin), stated in the lease;
the noise diagnostic, in areas exposed to airport noise.

Validity periods to keep an eye on

Each diagnostic has its own validity period: the DPE lasts ten years, the ERP six months, and the electricity and gas diagnostics six years for a letting. The CREP is unlimited if it reveals no lead, otherwise it must be redone. A diagnostic that has expired at the time of signing is treated as a missing diagnostic.

Who carries out and who pays for the diagnostics

The diagnostics are the landlord’s responsibility and must be carried out by a certified diagnostician, independent of the owner. Their cost is deductible from property income under the régime réel. Grouping the diagnostics into a single visit reduces the bill.

The consequences of a missing or incorrect diagnostic

An incomplete or expired DDT deprives the lease of certain protections and may allow the tenant to hold the landlord liable, or even to seek a rent reduction or damages. An incorrect, legally binding DPE exposes the landlord to a claim. Centralising the diagnostics and their expiry dates avoids oversights when reletting.

Frequently asked questions

Which diagnostics are mandatory to let a property?: At a minimum the DPE and the habitable floor area; depending on the home, these are joined by the ERP, lead (before 1949), asbestos (before 1997), electricity and gas (installations more than 15 years old) and the noise diagnostic in the areas concerned.
Who pays for letting diagnostics?: The landlord. The diagnostics must be carried out by a certified diagnostician and their cost is deductible from property income under the régime réel.
How long is a diagnostic valid?: It depends: ten years for the DPE, six months for the ERP, six years for electricity and gas in a letting. A diagnostic that has expired at signing is treated as missing.
What does the landlord risk by forgetting a diagnostic?: The tenant can hold them liable and seek a rent reduction or damages. An incorrect, legally binding DPE also opens the door to a claim against the landlord.