Secure your Paris sales against quarry-related litigation

Why Paris notaries use Sous-sol Paris

Paris and its inner suburbs contain more than 770 kilometres of underground tunnels left by the historic extraction of Lutetian limestone and gypsum. A significant share of buildings erected before 1900 sits above sensitive zones listed by theInspection Générale des Carrières (the IGC, Paris quarry inspectorate). Every year, sinkholes (fontis, localised collapses) are reported in the 5th, 6th, 13th, 14th, 15th, 16th and 19th arrondissements.

For a notarial office, the question is not whether you will come across an at-risk property, but how many a year. Yet the statutory risk statement (ERP) (Act of 30 July 2003) and prefectural notices do not always set out the exact nature of the risk at address level. Our tool fills that gap in 30 seconds.

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How it works

1. Create your account — professional details (email, firm, SIRET optional) — 1 minute.
2. Enter the Paris address of the property being sold, or import a multi-address CSV for a portfolio audit.
3. Receive the report as a PDF in 30 seconds: map summary, geological context of the arrondissement and risk level assessed from public data from the IGC, BRGM/Géorisques, the City of Paris and Institut Paris Région.
4. File the report with the sale record: your time-stamped proof of pre-contractual diligence.
5. If a risk is confirmed, direct the client to an official IGC enquiry (10 €, 30 days) and/or a G1/G2 geotechnical study.

Legal framework — what the law says

The seller’s duty of information (art. 1112-1 of the French Civil Code)

“The party who knows information the importance of which is decisive for the other party’s consent must inform that party of it, where the latter legitimately does not know the information or relies on its contracting partner.” (source: Notaires de France)

The location of a building above a former quarry is an objective fact, verifiable through the IGC’s public data, and being unaware of it plainly affects the buyer’s consent — not least as regards the value of the property, the potential cost of underpinning works and its insurability.

Statutory risk statement — ERP (Act no. 2003-699 of 30 July 2003)

Since 1^st June 2006, sellers and landlords have been required to provide the buyer or tenant with a statutory risk statement issued less than six months before the date the contract is concluded. The document is generated via errial.georisques.gouv.fr. However, the national ERP does not systematically cover older Paris underground cavities that fall outside a PPRN natural-risk prevention plan — hence the need for a complementary pre-assessment.

Failure to comply with the ERP obligation can lead to rescission of the contract or a reduction in price.

Latent defects (art. 1641 of the French Civil Code)

“The seller is bound by a warranty against hidden defects in the thing sold which render it unfit for its intended use, or which so impair that use that the buyer would not have acquired it, or would have paid a lower price, had they known of them.”

Case law has expressly classified the existence of underground quarries causing structural instability among recognised latent defects (Le Figaro Immobilier). The remedies open to the buyer are rescission of the sale (art. 1644) or a reduction in price (art. 1646). A warranty-exclusion clause is valid only where the seller is a non-professional and acting in good faith — a condition that falls away as soon as the seller (or their diligent notary) could reasonably have known of the risk.

The Paris IGC — the official authority

L'Inspection Générale des Carrières is the department responsible for preventing ground-movement risks linked to former quarries and the dissolution of Antediluvian gypsum in Paris and the three Petite Couronne départements. Contact details:

• Address: 86 rue Regnault, 75013 Paris
• Telephone: 01 40 47 58 00 (Monday to Friday, 9am–12pm and 2pm–5pm)
• Official enquiry: 10 €, average turnaround 30 days
• Emergency/incident: 3975 (Paris number)

Source: City of Paris — IGC.

The most exposed arrondissements

Paris geology concentrates risk in well-identified areas. These are the arrondissements where a pre-assessment is particularly worthwhile before the preliminary sale agreement:

• 5e, 6e, 13e, 14e, 15e — former Lutetian limestone quarries (Left Bank, Montsouris plateau, Gobelins, Denfert-Rochereau, Vaugirard).
• 16e, 17e, 18e, 19e, 20e — former gypsum and coarse limestone quarries (Passy, Chaillot, Montmartre, Belleville, Ménilmontant, Buttes-Chaumont).
• Petite Couronne — Ivry, Gentilly, Le Kremlin-Bicêtre, Arcueil, Bagneux, Malakoff, Vanves, Issy-les-Moulineaux, Bois-Colombes.

Model clause to insert in the preliminary sale agreement

Below is a model clause that you can adapt and insert in the preliminary sale agreement where the pre-assessment reveals moderate or high exposure. Please check it with your reference colleague, as this wording is indicative only:

“The SELLER declares that they have informed the BUYER that the property hereby sold is located in an area historically affected by the presence of former underground quarries / by gypsum dissolution [delete as applicable], as established by the pre-assessment dated [DATE] provided by Sous-sol Paris (SIRET [X]) and appended hereto, and in the absence of an up-to-date official enquiry with the Inspection Générale des Carrières. The BUYER declares that they have received this information, have read it and accept any consequences it may entail. It is expressly recalled that this document replaces neither the mandatory statutory risk statement (ERP) nor any geotechnical survey.”

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