MaPrimeRénov’ in September 2026: What Foreign Property Owners Must Check Before Renovating in France

From 1 September 2026, the French MaPrimeRénov’ rules for major renovation projects become more demanding where a gas boiler remains after the works. The change matters to a British, American or Australian buyer who has budgeted for an energy renovation of a French house, especially where the financial plan assumes a grant. It also matters to an owner who has already exchanged quotations with an installer but has not yet secured the administrative approval.

This article separates three questions that are often confused. First, what the September rule changes for the grant application. Secondly, what the private building contract still requires from the contractor, regardless of public funding. Thirdly, what evidence and remedies may be available if the work is badly designed, delayed or defective. A grant is not a substitute for technical due diligence, a properly drafted contract, insurance checks or a realistic cash-flow plan.

The recent English-language property press has reported that major renovation applications may be refused where the property retains a gas boiler after completion. A 26 August 2026 property news digest also warned buyers planning renovation work to check the heating system and the likely funding route before relying on grant support. These reports are useful alerts, but the grant authority’s current conditions and the documents in the individual file remain decisive. The public programme does not rewrite the Civil Code or guarantee the performance of an installer.

I. The September 2026 decision before works begin

A. What the new grant risk means for a foreign buyer

The first practical distinction is between eligibility for public assistance and the legal quality of private works. A foreign owner may have a valid contract with a contractor and still lose an expected grant because the planned project does not satisfy the applicable programme conditions. Conversely, an application that is accepted does not prove that the proposed heat pump, insulation package or ventilation system is suitable for the building.

The reported September change concerns the major-renovation route, commonly described as rénovation d’ampleur. The project should therefore be analysed as a complete package rather than as a promise that one item will automatically generate financial assistance. If a gas boiler is to remain in service, the owner must ask the scheme administrator, in writing and before commitment, whether the application is excluded, whether a different route applies, and which date controls: submission, approval, commencement or completion.

This timing question is critical for a non-resident. A contractor may be ready to start while the owner is in London, New York or Sydney. A local representative may be exchanging emails in French, and an installer may describe the project as “eligible” without having authority to bind the grant administrator. The owner should obtain the grant decision in the applicant’s name, preserve the submitted scope of works, and ensure that every quotation uses the same address, surface area, heating description and identity of the applicant.

Do not treat a verbal estimate of a grant as committed finance. Build the budget in two versions: one with the expected assistance and one without it. Include VAT treatment, design fees, energy assessment costs, temporary accommodation, currency movements, bank charges and the cost of bringing the property to a safe condition before the main works. Tax consequences for a non-resident owner may also matter, but they require separate tax advice and should not be inferred from the renovation programme.

The MaPrimeRénov’ decision can also affect a purchase. If the renovation property is being acquired, make the financing assumption a condition in the purchase negotiations where possible. The compromis de vente (preliminary sale agreement) should identify the intended works and avoid representing a grant as certain unless the relevant written approval already exists. A buyer should consider whether the project can be abandoned, redesigned or funded privately if the grant is refused.

For a broad review of the purchase process, an English-speaking buyer can consult the firm’s authorised guide to French real-estate law and property transactions. That general information should not be read as an approval of a particular renovation budget.

B. A pre-application and pre-contract checklist

Before signing or paying a substantial deposit, the owner should create one controlled file containing the following documents:

• the current title and the exact description of the building;
• the energy assessments and any technical audit used for the project;
• the existing heating, ventilation and hot-water specifications;
• the detailed scope, plans, quantities, brands and performance assumptions;
• the contractor’s identity, registration details and relevant insurance certificates;
• the grant application, acknowledgements, requests for further information and decision;
• the signed quotation, payment schedule, completion date and procedure for variations;
• photographs and dated records of the pre-work condition; and
• the evidence showing who is authorised to communicate for an owner abroad.

Do not allow the grant file and the construction file to diverge. If the application describes a complete replacement of the heating system but the quotation preserves the boiler as a back-up, obtain a written clarification before work starts. If insulation thickness, ventilation or surface areas change, ask whether the application must be amended. A contractor’s sales document is not a decision by the public administrator.

The contract should define what “completion” means. It should state whether the contractor must deliver commissioning certificates, operating instructions, conformity documents, warranties and evidence of the final configuration. For a property that will be occupied intermittently, include remote access to the site, a named contact, photographs at milestones and a process for urgent failures. A foreign owner should also decide in advance who can attend the handover and sign a reception document.

Payment deserves particular care. Avoid paying the entire price before inspection and reception merely because the installer says that the grant requires an invoice. A staged schedule should correspond to objectively verifiable progress. Keep the bank transfer references, invoices and proof of any grant-related payment. If the programme requires an approved professional or a specified sequence, the contract should identify that requirement rather than leaving it to informal assumptions.

Article 1103 of the Civil Code states: “Les contrats légalement formés tiennent lieu de loi à ceux qui les ont faits.” The rule means that the signed contract matters between the parties. It does not turn an inaccurate quotation into a technically adequate design, and it does not make the public authority a party to the installer’s obligations. The official text is available at Article 1103 of the Civil Code.

II. Construction liability, reception and remedies

A. The heating system may fall under different legal regimes

A replacement heat pump, boiler or ventilation unit is not automatically covered by the ten-year garantie décennale (ten-year building warranty). The classification depends on the nature of the work, the relationship between the equipment and the existing building, the date and form of reception, and the seriousness of the damage. The owner should preserve the full technical file because a short invoice description may not show what was actually built or modified.

Article 1792 provides that a constructor is liable as of right for damage compromising the solidity of the work or making it unfit for its intended purpose, unless the constructor proves a foreign cause. The official wording is available at Article 1792 of the Civil Code. The rule protects the owner or purchaser in the circumstances defined by the statute; it is not an automatic promise that every underperforming appliance has ten-year cover.

The third civil chamber’s decision of 10 July 2025, Cass. 3e civ., 10 July 2025, no. 23-22.242, concerned the supply and installation of a heat pump on an existing building. The Court reproduced the principle that equipment installed as a replacement or addition, where it is not itself a work, falls neither under the ten-year warranty nor the two-year operating warranty, but under ordinary contractual liability. It then approved the conclusion that the heat-pump installation was not a work because only very modest work was done to the building. For a foreign owner, the practical lesson is to identify the legal and technical scope before assuming that the installer’s insurance will answer every failure.

Article 1792-3 provides: “Les autres éléments d’équipement de l’ouvrage font l’objet d’une garantie de bon fonctionnement d’une durée minimale de deux ans à compter de sa réception.” The current text is available at Article 1792-3 of the Civil Code. That provision concerns the operating warranty for the relevant equipment; it does not erase the distinction drawn by the 2025 heat-pump decision.

The same issue can arise where the renovation is more substantial. In its decision of 30 May 2024, Cass. 3e civ., 30 May 2024, no. 22-20.711, the Court held that mandatory insurance does not cover damage to an existing structure caused by a new work unless there is both technical indivisibility and total incorporation of the existing structure into the new work. The owner of an old house should therefore ask the contractor and insurer to explain separately what is new, what is retained and what insurance activity is declared.

In another decision, Cass. 3e civ., 25 September 2025, no. 23-18.563, the Court treated extensive renovation of refractory linings in an industrial installation as a work under Article 1792. The facts are not a domestic grant case, but the reasoning illustrates why the scale and construction techniques matter. A project described commercially as “installing a heating unit” may involve structural openings, waterproofing, flues, electrical systems, roof work or substantial adaptation. The contract and technical documents should describe those parts precisely.

Article 1792-7 excludes equipment whose exclusive function is to permit a professional activity in the work from the statutory concept of equipment. Its official text is available at Article 1792-7 of the Civil Code. It is not normally the central provision for a private home, but it reinforces the need to classify the building and the function of the installation rather than relying on an English translation of a sales brochure.

B. Reception, insurance and a disciplined response to defects

Réception (formal acceptance of the works) is a decisive stage. Article 1792-6 defines reception as the act by which the owner accepts the work with or without reservations, either amicably or, failing that, judicially, and states that it is made contradictorily. It also governs the one-year perfect-completion warranty for defects reported at reception or notified in writing afterwards. The official text is available at Article 1792-6 of the Civil Code.

The decision of 20 March 2025, Cass. 3e civ., 20 March 2025, no. 23-20.475, is particularly practical for an owner abroad. The Court considered unfinished apartments and a house with missing heating, windows and other works. It stated that payment in full and taking possession may create a presumption of tacit reception, but it also required the lower court to examine that issue when it had been argued. A foreign owner should never assume that moving furniture in, paying an invoice or receiving keys gives the same evidential result as a carefully documented reception.

At reception, list every visible defect and incomplete item in clear written reservations. Use photographs, serial numbers and dates. If the owner cannot attend, appoint a representative with written instructions and require the contractor to send the signed document immediately. A reservation should identify the location and practical consequence, not merely say “to be checked”. A later written notification should be sent for a defect discovered after reception, with proof of delivery.

Do not instruct a second contractor to dismantle the system before preserving evidence, unless an urgent safety measure is necessary. Obtain an independent technical assessment, retain the original settings and ask for a controlled diagnostic. If the property is at risk of water damage, freezing, fire or unsafe emissions, make it safe first, but record the reason, the emergency work and the condition before intervention.

Insurance correspondence has its own deadlines and evidential risks. The third civil chamber’s decision of 3 April 2025, Cass. 3e civ., 3 April 2025, no. 23-16.055, states: “l’assureur, qui a accepté, dans le délai de soixante jours, la mise en jeu de la garantie, ne peut plus contester celle-ci”. The Court explained that an insurer which accepted the claim within the statutory period could not later contest the principle of cover on the ground that the defects were not ten-year defects, and that the necessary additional indemnity could be due for the declared damage. The owner should therefore preserve the initial declaration, the date received, the insurer’s response and every subsequent estimate.

A practical timetable helps prevent the file from becoming unmanageable. On the day a defect is noticed, record the date, room, weather conditions, operating settings and any warning displayed by the equipment. Within the next few days, notify the contractor and the relevant insurer in writing, asking for a response and an inspection date. Within the first month, obtain an independent technical view if the contractor’s explanation is disputed. Do not wait until the end of a warranty period to discover that a notification was sent to the wrong legal entity or to an unmonitored email address.

For an owner living overseas, electronic records should be supplemented by reliable delivery evidence. Send the notice to the address appearing on the quotation and insurance certificate, and use a method that records dispatch and receipt. Keep the original files rather than only screenshots. If a local property manager is involved, instruct that manager not to approve variations, repairs or waivers without written authority. A friendly message saying that a problem is “sorted” may later be read as an abandonment of a claim, even where that was not the owner’s intention.

The quotation should also answer what happens when the grant administrator changes the project. If the authority requires a different heating system, the contractor should issue a revised scope and price rather than silently substituting equipment. Any variation should state its impact on the grant, the completion date, performance targets, warranties and insurance. For a non-resident, a variation signed during a video call should be followed by a dated document in French or with a reliable translation, signed by the parties and stored with the original contract.

Heating performance should be tested under realistic conditions. Ask for commissioning data, balancing records, flow temperatures, controls, insulation interfaces and ventilation operation. A system that works during a short summer demonstration may not heat an old stone house in winter. The owner should ask the installer to explain assumptions about occupancy, room temperatures, existing emitters and electricity supply. If the promised result is an energy label improvement, preserve the baseline assessment and the method used to measure the final result, but do not confuse an energy rating with a contractual guarantee of comfort or savings.

Where works affect a co-owned building, additional permissions may be needed before the contractor starts. A heat pump, external unit, roof penetration, façade insulation or flue can affect common areas or the appearance of the building. The owner should check the co-ownership rules and any general meeting decision before signing an irreversible order. A grant approval cannot replace an authorisation required under the property’s internal rules or planning law. If the project is in a protected area, the architect or local authority may impose further requirements.

These checks are particularly important when the buyer has not yet completed the acquisition. The seller’s promise that “the grant is available” should be tested against the applicant’s identity, the property’s status and the programme’s deadlines. If the seller has already begun work, the buyer should identify who signed the contractor agreement, who paid, who received the grant and who will be entitled to make a claim. The transfer of a property does not automatically transfer every administrative entitlement or every contractual right.

That decision does not mean every insurer response is an acceptance, or that every renovation failure is covered. Read the wording carefully. Ask the insurer to state whether it accepts the principle of cover, reserves its position, requests an expert assessment or refuses the claim. Avoid describing the defect inconsistently in different letters. If the insurer sends an expert, attend remotely if necessary and provide the expert with the signed contract, plans, invoices, reception document and photographs.

The decision of 6 March 2025, Cass. 3e civ., 6 March 2025, no. 23-18.093, adds a useful limit: mandatory damage insurance does not necessarily cover every cost associated with remedial works. The Court excluded additional security-agent costs from the compulsory cover described in the case, while addressing the allocation of responsibility between co-obligors. A non-resident owner should therefore separate repair, demolition, temporary accommodation, security, storage and other consequential costs in the claim rather than presenting one unexplained total.

The decision of 12 March 2026, Cass. 3e civ., 12 March 2026, no. 24-10.927, concerned renovation of a house and an insurer that sought to limit its contribution to the percentage represented by one insured trade. The Court required the lower court to examine whether the covered defects alone justified demolition and reconstruction, rather than accepting a purely arithmetic allocation. The practical point is not that an insurer must always fund an entire project. It is that the causal and technical analysis must be done properly, with the policy activities and the nature of the damage identified.

Finally, the 2025 decision of 10 July on the replacement heat pump and the 2025 decision of 20 March on reception show why a dispute should be prepared before it becomes urgent. The owner needs the identity of the contracting party, the exact insurance activity, the date of reception, the contract price, the payment record and a technical explanation of the defect. A foreign owner should also check which court and law clauses appear in the contract, while remembering that mandatory French construction rules may apply to French property and French works.

Article 1217 lists the principal responses to non-performance: “La partie envers laquelle l’engagement n’a pas été exécuté, ou l’a été imparfaitement, peut”. The text then refers to suspension, forced performance, price reduction, termination and damages, subject to compatibility and the circumstances of the case. The official text is available at Article 1217 of the Civil Code. The remedies are not self-executing: notice, proportionality, proof of breach and the contract’s payment terms remain important.

Conclusion

The September 2026 MaPrimeRénov’ change should be treated as a pre-project decision point, not as a promise of funding. A gas boiler retained after a major renovation may affect eligibility, and the answer must be confirmed against the current administrative conditions and the owner’s actual file. The safest approach is to model the project without the grant, align the grant application with the technical quotation, check the contractor’s insurance and document reception carefully.

The Civil Code provides several distinct regimes, and recent third civil chamber decisions show that the classification of a replacement heating system, the existence of a reception, the treatment of an existing building and the insurer’s response can change the analysis. A foreign owner who preserves the documents, records reservations, reports defects promptly and separates grant questions from private liability will be in a stronger position to obtain a technically informed assessment of the available options. No legal outcome can be assumed in advance, particularly where the works, insurance policy or grant file is incomplete.