The state of risks and pollution (ERP) lists natural, mining, technological hazards, soil pollution, and radon exposure to which a property is subject. This diagnosis affects the validity of a sale: an absent, incomplete, or erroneous ERP can lead to the cancellation of the transaction or a decrease in price. Before signing a preliminary agreement, each section of this document deserves careful reading, parcel by parcel.
Parcel Verification of the ERP: Why the Municipal Scale is Not Enough
Most buyers rely on the municipal summary of risks. This approach overlooks very localized situations. The zoning must be verified at the exact parcel scale, not just at the municipal level.
A natural risk prevention plan (PPRNP) can classify a parcel as a red zone (unbuildable or with heavy prescriptions) while the neighboring parcel remains in a blue zone. The same discrepancy exists for technological (PPRT) or mining (PPRM) risk prevention plans. Cross-referencing the property’s address with each active plan allows for the identification of these discrepancies.
In practice, it is necessary to compare the information in the ERP with seismic zoning, radon mapping, and the history of natural disaster decrees (CATNAT) published for the municipality. A property located in an area that has been subject to several recent CATNAT decrees presents a different risk profile than one located just a few streets away.
Each real estate ERP to verify before purchase benefits from being cross-referenced with these parcel data to avoid an overly broad reading of the risk.
Obligation to Provide the ERP from the First Property Visit
Since January 1, 2023, the ERP must be provided to the buyer from the first visit to the property, and no longer at the stage of the preliminary sales agreement. This change alters the timeline of information.
In practice, the seller or real estate agent must have an up-to-date ERP even before opening the door to visitors. If the document is not presented at that time, the buyer may legitimately question the compliance of the sales process.
The property listing itself must mention the existence of identified risks. This requirement goes beyond the scope of the diagnosis handed over in person: it imposes transparency from the first contact, including on online portals. An informed buyer therefore checks the consistency between what is stated in the listing and what is detailed in the ERP provided during the visit.
Content of the ERP: Sections to Read as a Priority
The ERP form follows a regulatory framework. Not all sections carry the same weight depending on the property’s location. Three categories concentrate the most frequent issues.
- Natural Risks: floods, landslides, wildfires, avalanches. Classification in a flood zone directly modifies insurance conditions and possibilities for construction or extension.
- Technological and Mining Risks: proximity to a SEVESO site, presence of old mining galleries. These elements affect resale value and applicable urban planning constraints on the parcel.
- Soil Pollution and Radon: a plot located in an information sector on soils (SIS) indicates proven or suspected pollution. The radon potential, classified by zone, may impose ventilation measures in the housing.
Each section refers to a specific prevention plan. Verifying that the ERP correctly cites the relevant plans (PPRNP, PPRT, PPRM) and that their dates correspond to the approved and publicly released versions is a reflex that protects against an outdated document.
Validity and Date of the ERP: A Common Trap
The ERP has a validity period of six months. A diagnosis established seven months before the signing of the preliminary agreement is void, even if no changes have occurred in the zoning. An expired ERP makes the sale contestable.
Beyond the date, it is necessary to verify that the document was established based on the most recent prefectural decrees. A prevention plan may be revised between the completion of the ERP and the signing of the deed. In this case, the seller must provide a new diagnosis that includes the update.
The ERP in the Overall Due Diligence of a Real Estate Purchase
The ERP only covers part of the preliminary checks before purchasing a property. It provides information on risks related to the land and environment, but it says nothing about the condition of the building, energy performance, or urban planning constraints.
A buyer who limits themselves to the ERP misses crucial points: easements, urban preemption rights, presence of asbestos or lead, DPE results. The ERP is part of a set of mandatory real estate diagnostics, each illuminating a different aspect of the property.
The cross-referencing is particularly useful when the ERP indicates a risk of flooding or landslide. In this case, consulting the urban planning certificate allows one to know if any constructive prescriptions apply to the parcel. Similarly, a plot classified in SIS may require a supplementary soil study before any project work.
The relationship between the ERP and urban planning documents (local urban planning plan, municipal map) sometimes reveals incompatibilities between the purchase project and the actual constraints of the land. A property located in a medium seismic zone, for example, may be subject to seismic standards that increase renovation costs.
Reading the ERP is not just about checking boxes. It involves identifying, for each mentioned risk, its concrete consequences on insurance, buildability, property value, and daily comfort. A clean diagnosis does not guarantee the absence of constraints, but an incomplete diagnosis guarantees a potential dispute.