Many French houses outside towns are not connected to a public sewer. Their wastewater goes into a system on the plot, such as a septic tank followed by a treatment stage, or a small treatment plant. That system comes with a report and, if the report finds it non-compliant, a deadline and works the buyer may have to pay for. This guide explains what the report says, what a non-compliant finding means and what has to happen after you buy.
If a French house has its own septic system, the seller must provide a SPANC report, annexed to the preliminary contract and less than three years old when the deed is signed. If it finds the system non-compliant, works are due within one year of the sale. Read the report before you sign.
What the SPANC report is, and who may issue it
The SPANC is the public service for non-collective sanitation, run by the commune or a public body in charge of sanitation. It carries out the mandatory checks on septic systems, and the ministry’s guidance says it is the only service authorised to provide the document required on a sale. You can get its contact details at the town hall.
Since 1 January 2011 the sanitation report has been part of the technical file on the property, alongside the reports on energy, electricity, lead and asbestos; the full set is explained in the seller’s reports when buying a house in France. It is to be annexed to the promise of sale or, if there is none, to the deed of sale, and it must be less than three years old when the authentic deed is signed. If no check has ever taken place, or the last one is older, the seller must have the SPANC carry out a new one at the seller’s expense.
What the report says matters more than the fact that it exists. According to the ministry’s guidance, the SPANC describes the installation and states whether it shows malfunctions or risks for health or the environment. Where the installation is not safe for health or the environment, ANIL, the national housing information agency, says the document lists the works needed to bring it into compliance.
When to read the report, and who pays before the sale
Read the SPANC report before you sign the preliminary contract: it is to be annexed to that contract. The ministry’s guidance for buyers and sellers adds that a prospective buyer should have it as early as possible, so as to know whether works will be needed. That is also the point at which the finding can shape the price.
Compliance works before the sale are for the seller to pay, but the seller may decide not to carry them out. The seller then informs the buyer, who decides whether to buy the house as it is, and the works can become part of the negotiation on the price.
A missing report has consequences for the seller. Service-public.fr says a seller who does not hand over a valid sanitation report can be held liable for a hidden defect, and that the notary can be liable for completing the sale without it, or while aware of false information that misled the buyer.
What a non-compliant finding means
A non-compliant finding does not always mean the same deadline. The 2012 rules for checking existing systems name three categories: a danger to people’s health, a proven risk of environmental pollution, and an installation that is incomplete, significantly undersized or has major malfunctions. Maintenance faults or wear lead only to recommendations.
| Finding in the SPANC report | Outside a sale | After a sale |
|---|---|---|
| a) Danger to people’s health | works within 4 years of the document listing them | works within 1 year of the deed |
| b) Proven risk of environmental pollution | works within 4 years of the document listing them | works within 1 year of the deed |
| c) Incomplete, significantly undersized or with major malfunctions | the commune identifies the works needed; article 4 sets no deadline for them | works within 1 year of the deed |
| Maintenance fault or wear of a component | recommendations to improve operation | not one of the three categories |
Arrêté of 27 April 2012, articles 2, 4 and 5, read in the consolidated text on AIDA (INERIS), retrieved September 2026. Outside a sale, the period runs from the notification of the document listing the works, and the mayor can shorten it according to the risk. In a zone with health or environmental stakes, the defects in row c fall under a or b.
Location can change the category. An installation that is incomplete, significantly undersized or has major malfunctions counts as a danger to people’s health in a zone with health stakes, and as a proven pollution risk in a zone with environmental stakes, where the river-basin water management plans show contamination of water bodies by non-collective sanitation.
Zones with health stakes include the protection area of a public drinking-water catchment where the prefect’s order sets specific rules for non-collective sanitation. An installation less than 35 metres up-gradient of a declared private well used for drinking water, for a building that cannot be connected to the public supply, also counts as a danger to health.
The septic tank regulations in France look at how a system is built, not only at how it works, and some older designs are named in them. The annex to the 2012 rules lists a septic tank on its own, without a treatment stage, among the signs of an incomplete installation, and a septic tank used for all household wastewater among the signs of a significantly undersized one. An older system can therefore be non-compliant even if it seems to work.
After you buy: the year after the deed
After the sale the obligation passes to you. ANIL says a buyer whose system was non-compliant at the signing of the deed must have the compliance works carried out within one year, and that a buyer who does not carry out the prescribed works within three years is liable to a fine.
ANIL does not say when those three years start; the one-year deadline applies regardless.
The ministry’s guidance explains how the SPANC follows this up. Within a month of the deed, the notary must send it a certificate with the date of the sale, the identification of the property and the buyer’s name and address. The new owner then submits a rehabilitation project to the SPANC, which must confirm that the project complies before any works start.
Once the works are done, the SPANC checks them. Under the 2012 rules, it checks the works during a site visit before backfilling, and makes a follow-up visit, also before backfilling, to check that works it has required were carried out on time. The year therefore has to cover the project, its approval and the installation, not only the digging.
How often the SPANC checks, and what the national figures say
Outside a sale, the SPANC checks each installation at intervals of no more than ten years; the commune sets the actual frequency in its service rules, and it can depend on the type of installation and the last findings. The owner must be given at least seven working days’ notice of a visit.
Where a system endangers health or poses a proven pollution risk, the 2012 rules allow more frequent checks for as long as the danger or risk lasts.
The national observatory of water and sanitation services gives an average compliance rate of 71.8% on 1 January 2025. It is the share of installations found compliant among those checked since each service was created, not among all systems in France, and the observatory warns that the indicator will only be truly meaningful once all homes covered by a SPANC have been checked. A national average says nothing about the system of the house you are buying.
This guide gives no cost figures: what the works cost depends on the system, the soil and the plot. Ask for quotes, and ask the SPANC what a compliant project would need, before you commit. Service-public.fr notes that the zero-interest eco-loan (éco-PTZ) can, under certain conditions, help finance the works.
How briven approaches septic systems
briven is preparing its launch in France. It cannot issue or replace the SPANC report and does not inspect a septic system. It is designed to rate wastewater pipes and pumping units among other building components, from the documents and photos you provide, with a stated confidence level, but it does not rate the septic tank or treatment system.
For the septic system itself, the SPANC report is the document that counts. You can join the waiting list on the English home page.
Frequently asked questions
The seller needs one. If the house is not connected to the public sewer, the seller must provide a report from the local sanitation service, the SPANC, dated less than three years at the signing of the deed. The SPANC is the only service allowed to issue it, and it is to be annexed to the preliminary contract, so read it before you sign.
Less than three years at the signing of the authentic deed of sale, according to service-public.fr. If no check has ever taken place or the report is older, the ministry’s guidance for buyers and sellers says the seller must ask the SPANC for a new check, at the seller’s own expense.
One year from the signing of the deed. The 2012 rules for checking existing systems require works for all three categories of non-compliance within a year of a sale. ANIL, the national housing information agency, adds that a buyer who does not carry out the prescribed works within three years is liable to a fine.
Before the sale, compliance works are for the seller to pay, but the seller may decide not to carry them out. In that case the buyer decides whether to buy the house as it is, and the works can become part of the price negotiation. After the sale, the obligation to carry them out lies with the buyer.
At intervals of no more than ten years. The law sets that maximum, and each commune fixes the actual frequency in its service rules, which can vary with the type of installation and what the last check found. Where a system endangers health or poses a proven pollution risk, the commune may check it more often.
Sources and standards(6)
- Ministère de la Transition écologique — Assainissement non collectif : acheteur ou vendeur d’une maison, ce qu’il faut savoirThe SPANC as the only service authorised to issue the document for a sale, the report in the technical file since 1 January 2011 and annexed to the promise of sale, works before and after the sale, and the notary’s notification to the SPANC.
- Service-public.fr — Diagnostic immobilier : assainissement des eaux usées (assainissement collectif et non collectif) (F31685)Validity of less than three years at the deed, the liability of the seller and the notary, and the éco-PTZ as a possible source of financing; page verified by the portal on 26 February 2025.
- AIDA (INERIS) — Arrêté du 27 avril 2012 relatif aux modalités de l’exécution de la mission de contrôle des installations d’assainissement non collectifZones with health and environmental stakes (article 2), the three categories and the one-year deadline after a sale (article 4), when the deadline runs and its shortening by the mayor (article 5), the notice period for visits (article 6), the maximum interval between checks (article 7), and the examples of incomplete and undersized installations in the annex.
- Code général des collectivités territoriales, article L2224-8 (copy published by SIVOM Nord Allier)The maximum interval of ten years between periodic checks.
- ANIL (Agence nationale pour l’information sur le logement) — Quels diagnostics ?The body that carries out the check, the report annexed to the promise of sale, the seller’s cost of a new report, the buyer’s one-year deadline after the deed, and liability to a fine after three years.
- Observatoire des services publics d’eau et d’assainissement — Indicateur P301.3Definition of the compliance rate of non-collective sanitation systems, its national value on 1 January 2025, and the observatory’s caveat on its meaning.