The Technical Diagnostic File (DDT)

What is the DDT?

The technical diagnostic file (DDT), established by the ordinance of 8 June 2005 on housing and construction, brings together in a single document all the reports or surveys that the seller is legally required to present when selling all or part of a built property, regardless of its intended use (residential, office, commercial).

The technical diagnostic file comprises up to 12 documents listed in Article L271-4 of the Construction and Housing Code. Not all documents will necessarily be required. For example, the termite survey will not be required if the property is not located in a termite-infested zone delimited by a prefectoral order.

Who is responsible for producing it and bearing the cost?

This file must be attached by the seller to any promise of sale, or failing that, to the notarial deed of sale (Construction and Housing Code, art. L 271-4 to L271-6 and R 271-1 to D271-5).

Penalties are provided for in the event that any of the documents is missing. This absence must be noted at the time of the notarial deed.

The costs of preparing the technical diagnostic are normally borne by the seller, as it falls within their duty to inform. However, the parties may agree to pass these costs on to the buyer.

You are the seller

Do not hesitate to consult your notary about your exact obligations. The law requires you to provide these documents, failing which you may be held liable for the consequences of this failure to inform. You cannot be exempted from this obligation.

You are the buyer

You must inform yourself so as not to be mistaken about the characteristics of the property you intend to purchase. These diagnostics give the buyer a clearer picture of their investment, its qualities and its shortcomings.

It is not impossible that in the future, additional checks will be added to the file, in the ongoing pursuit of better consumer information and protection.

List of Mandatory Property Diagnostics and Information for Sale (CCH, art. L 271-4)

1. The LEAD Diagnostic

This diagnostic is provided for in articles L. 1334-5 and L. 1334-6 of the Public Health Code.

Nature of the document: risk assessment report for lead exposure (CREP). It must be accompanied by an information notice summarising the health effects of lead (lead poisoning) and the precautions to be taken in the presence of lead-containing coatings.
Properties concerned: residential buildings or parts of buildings used for residential purposes whose building permit was issued before 1 January 1949.
Validity period: positive result: the report must have been produced less than one year before the signing of the promise of sale (CCH, art. D 271-5). However, if the report produced at the promise stage is no longer valid at the time of the notarial deed, it must be replaced by a new document (CCH, art. L 271-5 al 2). Unlimited validity if the result is negative.
Penalties: in the absence of a diagnostic, the seller cannot be exempt from the corresponding hidden defects warranty. The hidden defects exemption clause will therefore be ineffective with regard to the presence of lead.

2. The ASBESTOS Diagnostic

This document is provided for in article L. 1334-13 of the Public Health Code.

Nature of the document: a "report" or "survey" indicating the presence or absence of materials or products containing asbestos.
Properties concerned: all built properties whose building permit was issued before 1 July 1997 (CSP, art. R1334-23).
Validity period: if no trace of asbestos is detected, the validity is unlimited. Warning: if the diagnostic was carried out before 1 April 2013, it must be renewed in the event of a property sale, even in the absence of asbestos.
Penalties: the seller cannot be exempt from the corresponding hidden defects warranty. Any hidden defects exemption clause will therefore be ineffective with regard to the presence of asbestos.

3. The TERMITE Diagnostic

This document is provided for in article L. 126-24 of the Construction and Housing Code.

Nature of the document: report on the presence of termites.
Properties concerned: all built properties located in contaminated zones (delimited by prefectoral orders). See the map of departments covered by a prefectoral order delimiting termite-infested zones.
Validity period: 6 months maximum. Must be renewed in the event of a new municipal order declaring a new infestation zone (CCH, art. D 271-5). If the report produced at the promise stage is no longer valid at the time of the notarial deed, it must be replaced by a new document (CCH, art. L 271-5 al 2).
Penalties: in the absence of a report less than 6 months old attached to the notarial deed, the seller cannot be exempt from the corresponding hidden defects warranty. Any hidden defects exemption clause will therefore be ineffective with regard to the presence of termites.

4. The GAS Diagnostic

This diagnostic is provided for in article L. 134-9 of the Construction and Housing Code.

Nature of the document: report on the interior gas installation. A certificate of conformity issued by an approved body following gas installation works may serve as this report (CCH, art. R 126-41).
Properties concerned: residential buildings or parts of buildings used for residential purposes whose gas installation is more than 15 years old.
Validity period: the report (or certificate of conformity) must have been produced less than 3 years before its attachment to the promise or deed (CCH, art. D 271-5). If the report produced at the promise stage is no longer valid at the time of the notarial deed, it must be replaced by a new document (CCH, art. L 271-5 al 2).
Penalties: in the absence of a report less than 3 years old attached to the notarial deed of sale, the seller cannot be exempt from the corresponding hidden defects warranty. Any hidden defects exemption clause relating to the gas installation will therefore be ineffective.

5. The Statement of Natural and Technological Risks (State of Risks and Pollution – ERP)

This diagnostic is provided for in article L. 125-5 of the Environmental Code.

Nature of the document: statement of risks and pollution (natural, mining or technological hazards, seismicity, radon potential, and contaminated land).
Properties concerned: all types of properties located in an area covered by a technological risk prevention plan or a prescribed or approved natural risk prevention plan, in a radon potential zone, or in a seismic zone defined by decree.
Validity period: a report less than 6 months old must be attached to the promise of sale, or failing that, to the notarial deed. If the report produced at the promise stage is no longer valid at the time of the notarial deed, it must be replaced by a new document (CCH, art. L 271-5 al 2).
Penalties: in the absence of a valid report attached to the notarial deed of sale, the buyer may seek rescission of the sale or request a price reduction from the civil court.

6. The Energy Performance Diagnostic (EPD) and Energy Audit

The energy performance diagnostic and, where applicable, the energy audit are provided for in articles L126-26 to L126-33 and R126-15 to R126-20 of the Construction and Housing Code.

The energy performance diagnostic (EPD) is a document used primarily to estimate the energy consumption and greenhouse gas emission levels of a property (CCH, art. L 126-28).

The EPD also aims to combat energy poverty through measures prohibiting rental or limiting rent increases.

The EPD must be attached to the promise of sale, or failing that, to the notarial deed of sale.

Nature of the document: the EPD is a document containing the amount of energy actually consumed or estimated, and a classification based on reference values enabling the energy performance to be compared and assessed. It is accompanied by recommendations to improve this performance and the estimated theoretical costs of all uses listed in the diagnostic.
Properties concerned (CCH, art. R 126-15): properties covered by the EPD are enclosed and roofed buildings located in metropolitan France equipped with a heating or hot water system. By exception, buildings listed in article R126-15 of the Construction and Housing Code are not subject to the diagnostic (for example, a building intended to be occupied for less than 4 months per year).
Validity period: the validity of the energy performance diagnostic is set at ten years. Warning: for EPDs carried out between 1 January 2013 and 1 July 2021, validity is limited as follows:
- Diagnostics carried out between 1 January 2013 and 31 December 2017 are valid until 31 December 2022;
- Diagnostics carried out between 1 January 2018 and 30 June 2021 are valid until 31 December 2024.
Penalties: information relating to energy performance (e.g. class E rating) has been binding on the seller since 1 July 2021. The EPD therefore now has contractual value: in the event of an error, the buyer may take the matter to court to claim damages. Only the recommendations (e.g. loft insulation) retain a purely informative value.

Energy Audit

The EPD underwent a major reform following the "Climate and Resilience" law published on 24 August 2021.

The law made it compulsory to carry out an energy audit when selling a detached house or a building comprising several dwellings owned by a single owner:

from 1 April 2023, for the sale of an "energy sieve", i.e. a building with an energy performance diagnostic (EPD) rating of class F or G;
from 1 January 2025 for class E properties;
and from 1 January 2034 for class D properties (CCH, art. L 126-28-1).

The energy audit complements the diagnostic and enhances the buyer's information by setting out the various works required to potentially improve energy performance.

2025–2026 Updates

An action plan to restore confidence in the EPD and combat lenient diagnostics was launched in March 2025 through various legislative texts (Act 2025-594 of 30 June 2025, whose broader scope covers the fight against fraud in energy renovation and public subsidies, along with 5 ministerial orders). These texts notably introduce stricter oversight of certification bodies and diagnosticians, and also improve the energy label for electrically heated properties.

7. The ELECTRICITY Diagnostic

This diagnostic is provided for in articles L. 134-7, R 126-35 and R 126-36 of the Construction and Housing Code.

Nature of the document: report on the interior electrical installation.
Properties concerned: residential buildings or parts of buildings used for residential purposes whose electrical installation is more than 15 years old.
Validity period: the report must have been produced less than 3 years before the date of the promise (CCH, art. D 271-5), both for the interior installation report and for the certificate of conformity in the case of renovation works.
Penalties: in the absence of a report less than 3 years old attached to the notarial deed, the seller cannot be exempt from the corresponding hidden defects warranty.

8. The NON-COLLECTIVE SANITATION Diagnostic

This document is provided for in article L. 1331-11-1 of the Public Health Code.

Nature of the document: document resulting from the inspection of the individual sanitation installation.
Properties concerned: all built properties not connected to the public sewage network.
Validity period: 3 years.
Penalties (CCH, art. L 271-4): in the absence of a document less than 3 years old attached to the notarial deed of sale, the seller cannot be exempt from the corresponding hidden defects warranty. In the event of non-compliance of the installation at the time of signing the notarial deed, the buyer is required to bring it into compliance within one year of signing.

Good to know: if the property is connected to the collective sewage network, you may be required at the time of sale to provide the document established during the inspection of the connection by the municipality, attesting to its compliance with regulatory requirements (General Code of Local Authorities, art. L 2224-8).

9. The DRY ROT (MÉRULE) Diagnostic

Mérule (or Serpula lacrymans) is a fungus that attacks structural timber, particularly in houses.

Nature of the document: information on the presence of a dry rot risk.
Properties concerned: all built properties located in contaminated zones delimited by prefectoral order (CCH, art. L 131-3).
Validity period: no set duration.
Penalties: no penalty is provided for by legislation in the absence of this information.

10. The NOISE Diagnostic or "Statement of Aerial Noise Nuisances"

The noise diagnostic is a document that informs the future buyer of the existence of aerial noise nuisances. It is provided for in article L 112-11 of the Urban Planning Code.

It is attached to the promise of sale or, failing that, to the notarial deed of sale.

Nature of the document: statement of aerial noise nuisances.
Areas concerned: this diagnostic must be produced when the property is located in one of the noise zones defined by an aerodrome noise exposure plan provided for in article L. 112-6 of the Urban Planning Code. Consult the noise exposure plan.
Properties concerned: buildings or parts of buildings for residential or mixed professional and residential use, or undeveloped constructible properties that are the subject of a sale. When the property is located in one of the noise zones, a document clearly indicating this zone, the address of the online service where the noise exposure plan can be consulted, and the option to consult the plan at the town hall of the municipality where the property is located must be included in the technical diagnostic file.
Penalties: although the noise statement is only indicative, its absence allows the buyer to seek rescission of the contract or to request a price reduction from a judge.

11. Wood-Burning Heating Appliances

Based on the observation that open fireplaces generate significant carbon dioxide emissions not offset by new forest planting, as well as fine particle pollution, the Climate and Resilience Act of 22 August 2021 (art. 158) created an eleventh diagnostic to be included in the DDT (CCH, art. L271-4, I, 11°).

When the property is located within the perimeter of an atmospheric protection plan provided for in article L. 222-4 of the Environmental Code, the seller must include in the technical diagnostic file (DDT) a certificate attesting to the conformity of the wood-burning heating appliance with the installation and emission rules set by the departmental prefect.

12. Information on Orders Issued Under Public Safety and Sanitation Policing Powers

Since 11 April 2024, Act 2024-322 of 9 April 2024 on the Renovation of Degraded Housing requires disclosure of any orders that may have been issued under the public safety and sanitation policing powers applicable to buildings, premises and installations (CCH, art. L271-4, I, 12°).