In brief:
- In 2026, up to 9 diagnostics can be mandatory depending on the property and its location.
- The total cost of diagnostics is between 400 and 800 euros for an old home.
- An energy audit is mandatory for homes rated F or G since April 2023.
- The absence of a mandatory diagnostic can lead to sale cancellation or price reduction.
Mandatory diagnostics for property sale: 2026 overview
Mandatory diagnostics for property sale evolve regularly. In 2026, the Technical Diagnostic File (DDT) remains the central document of any property sale.
Systematic diagnostics
Some diagnostics apply to all properties for sale, regardless of construction date:
- DPE (Energy Performance Diagnostic)
- ERP (State of Risks and Pollution)
- Non-collective sanitation (if not connected to main sewer)
Diagnostics depending on property age
| Diagnostic | Properties concerned | Validity period | Average cost |
|---|---|---|---|
| DPE | All | 10 years | 100 to 250 euros |
| Asbestos | Built before 1997 | Unlimited if absent | 80 to 150 euros |
| Lead (CREP) | Built before 1949 | Unlimited if absent | 100 to 300 euros |
| Electricity | Installation over 15 years | 3 years | 100 to 200 euros |
| Gas | Installation over 15 years | 3 years | 100 to 170 euros |
Energy audit for thermal sieves
Since April 2023, homes rated F or G in the DPE must undergo an energy audit before any sale. This audit, more in-depth than a DPE, details works scenarios to improve performance.
“The energy audit goes beyond the simple DPE snapshot. It proposes a quantified action plan to reach at least class B or C.” — Ministry of Ecological Transition
Penalties for omission
The absence of a mandatory diagnostic exposes the seller to several risks:
- Sale cancellation for consent defect
- Post-sale price reduction
- Liability for hidden defects
Steps to build the DDT
- Identify necessary diagnostics based on property and area
- Call a certified diagnostician (COFRAC directory)
- Complete all diagnostics before signing the purchase agreement
- Attach the complete DDT to the purchase agreement
- Send documents to the notary
Frequently asked questions
What are the mandatory diagnostics to sell a house in 2026?
Mandatory diagnostics in 2026 in France are: DPE (energy performance), asbestos (for properties before 1997), lead (properties before 1949), termites (risk zones), electricity (installation over 15 years), gas (installation over 15 years), ERP (natural and technological risks), non-collective sanitation if concerned, and energy audit for F and G homes.
Who pays for property diagnostics?
Property diagnostics are at the seller’s expense. Their total cost for an old property varies from 400 to 800 euros depending on surface and required diagnostics. The seller must use a certified diagnostician.
How long are diagnostics valid?
Validity periods vary: DPE 10 years, asbestos and lead unlimited if negative, termites 6 months, electricity and gas 3 years, ERP 6 months. Check dates before signing so as not to have to redo an expired diagnostic.