What does the diagnostics file (DDT) not tell you?
The diagnostics file (dossier de diagnostic technique, DDT) brings together specific reports on the home: energy, lead, asbestos, electricity, gas, termites, drainage, the hazards statement and airport noise. It says nothing about the planning rules, permits granted to neighbours, the commune’s projects, whether past works were authorised, private easements or the general condition of the structure.
What the diagnostics file contains
The seller must attach the diagnostics file to the promesse or compromis (art. L271-4 of the Construction and Housing Code). Each report is only required in certain cases and has its own period of validity.
| Report | When | Validity |
|---|---|---|
| DPE (energy) | Almost always | 10 years |
| Lead (CREP) | Built before 1949 | 1 year if lead found |
| Asbestos | Permit before 1 July 1997 | Unlimited if none found |
| Electricity, gas | Installation over 15 years | 3 years |
| Termites | Area set by prefectoral order | 6 months |
| Hazards statement (ERP) | Hazard area | 6 months |
Add to these non-mains drainage, the noise report near an airport, the energy audit for a house rated E, F or G and, for works filed since 2023, the home information log (carnet d’information du logement).
Before you sign, other checks matter too, such as the questions before the compromis and what to check before buying. For one address, the free ScanAdresse preview shows for free what the registers say.
No planning rules
No report tells you which PLU zone the house is in, what the regulations allow to be built there, whether a public easement burdens the land or whether the house lies within a listed monument’s surroundings. The hazards statement flags risk prevention plans, but not the other rules. This information is found on the Géoportail de l’urbanisme, at the mairie or in a certificat d’urbanisme d’information.
The hazards statement itself (art. L125-5 of the Environment Code) has a defined scope: it says whether the address lies in an area covered by a risk prevention plan, a seismic zone, a radon potential zone or a soil information sector, and lists the natural-disaster claims the seller knows of. It does not say what the PLU forbids or allows on the parcel.
No neighbours and no projects
The diagnostics file looks only at the property being sold. It does not mention the building permit granted on the next plot, the buildable land bordering the garden, a development zone in preparation or land reserved for a road. These are found in the planning permission registers, on site (the permit notice boards) and in the PLU.
The neighbour’s building permit
No check that works were authorised
A conservatory, an extension or a loft conversion may have been built without a works declaration or a permit. The DPE measures the heated area; it does not check that it was authorised. Ask the seller for the permissions and the declaration of completion and compliance; if in doubt, the mairie keeps the files lodged, and the notary or a lawyer will tell you what a discrepancy implies.
No structural survey, no private easements
The diagnostics are not an inspection of the frame, the roof, the foundations, damp or cracks. Only a building professional you instruct can judge those. Likewise, private easements, party walls and mortgages appear in the deeds and at the land registry (service de la publicité foncière), not in the diagnostics file.
ScanAdresse replaces none of the diagnostics: for one address, it gathers from the public registers what the diagnostics file leaves out (PLU zone and regulations, public easements, listed-monument surroundings, recent permits in the cadastral section, Géorisques hazards, polluted soils), register by register; €29 including VAT, free preview.
Frequently asked questions
Can the diagnostics file be incomplete?
Yes, if a report required for that property is missing. The seller then cannot rely on the exclusion of the latent defects warranty for the point concerned. The notary checks the list before the deed.
Does the diagnostics file say if the house is in a flood zone?
The hazards statement flags it if the commune is covered by a prevention plan or another regulated zone. Géorisques also shows known zones outside any plan.
Is an old DPE still valid?
A DPE lasts 10 years, but those carried out before 1 July 2021 have no longer been valid since 1 January 2025.
Who checks what the diagnostics file does not cover?
Nobody by default: it is up to the buyer to read the PLU, the hazards and nearby permits, and to instruct a professional for the condition of the building. The notary checks what the deed needs.
Sources
- Service-public: property diagnostics to provide
- Service-public: hazards statement
- Service-public: certificat d’urbanisme
- Construction and Housing Code, art. L271-4
- Environment Code, art. L125-5
ScanAdresse is a private service by SRI Group BV (VAT BE1037052239), not connected to any public authority: it brings together public data, with the source and date of every item.
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