Works in a French co-ownership: when is a vote needed?

Purely private works: no authorisation

Each co-owner “has the use of the private parts included in their lot” and enjoys them freely. There is a single condition: not to infringe “either the rights of the other co-owners or the intended use of the building” (Act, art. 9). You can therefore, without going through the general meeting, knock down a non-load-bearing partition, refit a kitchen or change a floor covering (F31513).

Two limits remain, according to service-public.gouv.fr:

• the intended use of the building and the rules: in a purely residential building, a flat cannot become commercial premises;
• the neighbours’ rights: a new floor that insulates less well than the old one, causing noise for the flat below, is for example prohibited.

Works that infringe the intended use of the building or the rights of the other co-owners require unanimity (F31513).

Works affecting the common parts or the façade: article 25

Article 25, b of the Act makes subject to an absolute majority “authorisation given to certain co-owners to carry out, at their own expense, works affecting the common parts or the external appearance of the building and consistent with its intended use”. This majority means the votes of all co-owners, whether present, represented or absent (F2137).

Service-public.gouv.fr (F31513) cites among such works:

• opening up a load-bearing wall, which is part of the common structure;
• altering openings: windows, frames, fitting bars;
• installing flues or extract ducts or visible air conditioning.

If the works result in the appropriation or destruction of a common part, the article 26 double majority is required (F31513). On a partie commune à jouissance privative (common part with exclusive use), such as a terrace or garden, the general meeting decides under article 25 for a light alteration and under article 26 for a construction (service-public.gouv.fr, F31518).

The bridge. If the resolution does not obtain the article 25 majority but gathers at least one third of the votes of all co-owners, a second vote can be held immediately by the simple majority of article 24 (F2137).

Neither the syndic nor the conseil syndical (owners’ committee) can give this authorisation in place of the general meeting (F31513).

Preparing the request for the general meeting

To obtain authorisation, you have two options, each by recorded-delivery letter with acknowledgement of receipt (F31513):

1. ask the syndic to put the item on the agenda of the next annual general meeting;
2. request a specific meeting, whose costs you will pay in full.

Article 10 of the décret (decree) of 17 March 1967 requires a draft resolution to be attached. For works, you must add a document specifying their “location and nature”.

For accessibility works for people with disabilities and thermal insulation of the roof or floor, the decree requires more (art. 10-1, in force since 25 December 2025). A detailed description is needed: nature, location, duration, conditions of performance, brands, models and guarantees. This description must be accompanied by a technical works plan. Without it, the information item (accessibility) or the draft resolution (insulation) “is not entered on the agenda”. For insulation, once authorisation is obtained, the co-owner may start only after the two-month period for challenges has expired (art. 10-4).

Refusal, unauthorised works and appeals

If you are refused, you have 2 months from notification of the minutes to apply to the tribunal judiciaire (civil court) for annulment, through a lawyer (Act, art. 42; F31513). For improvement works, service-public.gouv.fr states that you can also ask the judge for authorisation to carry them out.

Without authorisation, the works are irregular. The syndicat (owners’ association) can demand that they stop, that the work be demolished and the premises reinstated, including through the courts (F31513).

Planning. The general meeting’s approval does not exempt you from planning authorisation. Changing windows (other than like-for-like replacement), creating an opening or changing the colour of the shutters may require it (F31513).

Urgent works: the syndic acts alone

Article 18 of the Act requires the syndic, “in an emergency, to have carried out on its own initiative all works necessary to safeguard” the building. Outside an emergency, ordering works without the general meeting’s authorisation is misconduct by the syndic (service-public.gouv.fr, F2608).

Where collective works require entry into your home, they must be notified at least eight days before they start, except in an emergency relating to safety or the preservation of property (Act, art. 9, I). A co-owner cannot object to works in the collective interest that have been properly voted if their private parts are not permanently impaired. They are compensated if they suffer loss (art. 9, II and III).

Which professional to consult

If your works turn a common part into a private part, the allocation of tantièmes (each lot’s share of the common parts) changes: service-public.gouv.fr states that the proposed new allocation is often drawn up by a géomètre-expert (chartered surveyor) or a notaire (notary), after which an amending deed to the règlement de copropriété (co-ownership rules) and the état descriptif de division (division schedule) is registered (F35451). Before buying a flat to renovate, the agent immobilier (estate agent) can obtain the general meeting minutes for you so you can check whether comparable works have already been authorised. See also our guide on the assemblée générale de copropriété (owners’ general meeting).