Mandatory Diagnostics Before Selling a Property in France

When selling a property in France, the law requires the seller to provide the buyer with a set of technical reports collectively known as the Dossier de Diagnostic Technique (DDT). This dossier ensures full transparency for the buyer while protecting the seller against potential claims related to hidden defects.

The DDT must be attached to the preliminary sales agreement (compromis de vente).

Below is the complete list of mandatory diagnostics, including the conditions for their completion and their respective validity periods.

1. Energy Performance Diagnostic (DPE)

• Mandatory for all property sales, without exception.

• Assesses the property’s energy consumption and its CO₂ emissions.

• Energy performance is rated on a scale from A to G.

• Validity: 10 years, provided the diagnostic was carried out after July 1, 2021.

2. Asbestos Diagnostic

• Mandatory for buildings whose building permit was issued before July 1, 1997.

• Includes inspection of walls, ceilings, floors, technical rooms, and construction materials.

• Validity: Unlimited if no asbestos is found. If asbestos is detected, periodic monitoring or specific measures may be required in accordance with current regulations.

3. Lead Exposure Risk Report (CREP)

• Mandatory for properties built before January 1, 1949.

• Detects the presence of lead in old paint and other coatings.

• Validity: 1 year if lead is detected; unlimited if no lead is found.

4. Gas Installation Diagnostic

• Mandatory for indoor gas installations over 15 years old.

• Checks the condition of pipelines, equipment, ventilation, and exhaust systems.

• Validity: 3 years.

5. Electrical Installation Diagnostic

• Mandatory for indoor electrical installations over 15 years old.

• Identifies risks such as short circuits, improper grounding, and outdated protective devices.

• Validity: 3 years.

6. Termite Inspection

• Mandatory only in departments and municipalities designated as risk zones by the prefecture.

• Particularly recommended in the southern regions of France.

• Validity: 6 months.

7. Risks and Pollution Report (ERP)

This document assesses the following risks:

• Floods

• Seismic risk

• Radon

• Industrial activity-related risks

• Technological zones

• Compliance with risk prevention plans (PPRs)

Mandatory for all properties located in areas exposed to at least one regulated risk.

Validity: 6 months.

8. Noise Exposure Diagnostic

• Mandatory if the property is located within a zone covered by the Airport Noise Prevention Plan (PPBE).

• Informs the buyer about the property’s exposure to flight paths and aircraft noise.

• Validity: Unlimited, provided the report reflects the current zoning plan.

9. Carrez Law Measurement — Measurement of Private Floor Area (Co-ownership)

• Mandatory for all properties in co-ownership, including apartments, houses, or premises forming a co-owned lot.

• Determines the exact private floor area, excluding walls, partitions, balconies, terraces, garages, cellars, and areas with a ceiling height under 1.80 m.

• A measurement error exceeding 5 % allows the buyer to request a proportional price reduction.

• Validity: Unlimited, provided no modifications or alterations affecting the floor area have been made since the measurement.

10. Individual Wastewater Treatment Diagnostic (Assainissement Non Collectif)

Mandatory for properties not connected to the public sewage system, which is common for villas.

The diagnostic includes:

• The condition of the septic tank or other wastewater treatment system

• Compliance with current health and safety standards

• The need for repair or upgrading, if applicable

Validity: Typically 3 to 8 years, but the notary requires a recent report at the time of sale, usually less than 3 years old.

11. Mérules (Wood Rot) Diagnostic — Inspection for Wood-Destroying Fungi (in certain departments)

• Mandatory in departments where the prefecture has issued an order identifying a risk of mérules (wood-destroying fungi).

• Checks the condition of the building’s load-bearing wooden structures.

• Validity: Variable; a recent report is often required.

Summary Table of Mandatory Diagnostics

Examples of Property Diagnostic Costs

Prices can vary depending on the region, the company, and the property size. Below is an estimate of typical costs on the French Riviera and in most regions of France.

1. Apartment 100 m² (in co-ownership)

Commonly required diagnostics: DPE, Asbestos (if built before 1997), Electrical, Gas (if present), ERP, Carrez Law Measurement, sometimes Termites and Noise.

Average cost for the full diagnostic package: €350 to €700.

2. Villa 300 m² with individual wastewater treatment (septic tank)

Required diagnostics: all standard diagnostics, plus Assainissement Non Collectif, Termites (if in a risk zone), Mérules (if prefectural order applies).

Average cost for the full diagnostic package: €700 to €1,300.

Depending on complexity, property size, and the condition of the wastewater system, the cost can reach up to €1,500.

Conclusion

Mandatory diagnostics are an essential part of any property sale in France. They ensure transparency and provide legal protection for both the seller and the buyer. Timely preparation of a complete Dossier de Diagnostic Technique (DDT) helps to avoid delays and misunderstandings during the completion of the sale.