Installing AC in a French copropriété: the complete approval guide

Fitting a split AC unit in a French apartment building is simple once you know the rules. The outdoor unit (groupe extérieur) has to go on or near the outside of the building, and that's common property (parties communes). You can't fix anything to a shared facade or roof terrace without permission, however discreet the unit. Below: which approvals you need, how the vote works, what to prepare, and what to do if the building's rules seem to block you.

Do you always need an AG vote for AC in a French apartment?

Almost always. In a copropriété (the building's co-ownership), an outdoor unit on the facade, the roof, a balcony, a shared terrace or a shared wall needs approval. That approval is a vote at the owners' general meeting (assemblée générale, or AG). Work that changes how the building looks from outside needs the vote too. Neither the syndic (the building's managing agent) nor the owners' council (conseil syndical) can give that permission alone.

The same goes for a through-wall unit with no outdoor box. It still needs two holes through the outside wall, which is a common part, so telling the syndic isn't enough. You need the AG vote.

A terrace only you can use is often still a common part, with a private right of use attached, so equipment fixed there needs the vote as well. The rare exception is a unit that sits entirely inside your own lot, can't be seen from outside and drains onto nothing shared. Ask the syndic to confirm before relying on it.

Some règlements de copropriété (the building's rulebook) permit AC units outright, and some ban them. Read yours before doing anything else; the syndic or a notaire (notary) can give you a copy.

What majority does the copropriété AG need to approve AC?

The loi du 10 juillet 1965 sets the rules for common property. An owner's private works that affect the common parts or the building's outside appearance need an absolute majority. That means more than half the votes of all co-owners, weighted by their tantièmes (ownership shares). Owners who stay away count against you, which is why this bar is hard to reach.

If the request falls short but wins at least a third of all votes, a second vote can be held straight away at the same meeting. That one needs only a simple majority of the owners present, represented or voting by post.

Co-owners have a legal right to install an EV charger in a shared car park (the "droit à la prise"). No such right exists for AC, so you need the vote.

How do you get your AC request onto the AG agenda?

1. Write to the syndic and ask for your project to go on the agenda of the next AG. Do it at least 6-8 weeks before the meeting. Syndics usually set a deadline for agenda items, and your technical details have to reach every owner before the vote.
2. Prepare the technical dossier (see the list below). The other owners will want to know exactly what they're approving.
3. The vote takes place at the AG under the majority rules above.
4. The minutes (procès-verbal) record the decision. Keep a certified copy. You'll need it when you sell, and the installer may ask for it before starting.

If the AG says no, your only real recourse is a court (tribunal judiciaire), where you'd argue the refusal was abusive. A clear dossier, a discreet position and answers on noise and looks before anyone asks give you the best chance at the first vote.

Does an AC unit on an apartment building need a déclaration préalable?

Usually, yes. Separately from the AG, fitting an outdoor unit to the outside of a building normally needs a déclaration préalable de travaux (planning declaration) filed with the mairie (town hall). It's a planning notification, lighter than full permission. The mairie has one month to reply, or two months in ABF (state heritage architects) conservation zones. No reply by then means it's accepted.

Ask the installer whether they file it or you do. In an ABF zone (near a listed building or in a protected area), the Architecte des Bâtiments de France reviews it. They may set conditions on where the unit goes or ask for screening.

What technical details do the co-owners need about your AC unit?

A good dossier answers the obvious objections before they're raised. Include:

• Where the outdoor unit goes: a photo or marked-up plan showing the exact spot, the bracket and how it will look from the street or courtyard. If it won't be visible from the main facades, say so.
• Unit size: height, width and depth in centimetres. A compact unit gets approved more easily than a bulky one.
• Noise: the sound level in dB(A) at one metre, from the maker's data sheet. Owners will expect this figure. Modern residential splits typically run at 45-55 dB(A) at one metre. If the building's rules set a limit, choose a model under it.
• Condensate drainage: how the water the unit produces when cooling will be drained. It can't drip onto a balcony below or into a shared gutter without proper pipework, and a clean solution is often made a condition.
• Installer details: the firm's name, its certificate for handling refrigerant, its insurance certificates and the devis (written quote) reference.
• The déclaration préalable: a copy if already filed, or a note that it will be filed before work starts.

What if the règlement de copropriété prohibits AC?

Some older règlements were written before split AC was common. They may carry a blanket ban on "appareils de climatisation", or a general clause about keeping the building's appearance. Whether such a clause blocks a discreet unit depends on its exact wording.

Don't ignore it. Ask a notaire or lawyer (avocat) whether it holds as written. You can also ask the AG to amend the clause and approve your unit at the same meeting. Changing the règlement usually needs a larger majority than the approval itself, so ask the syndic which applies.

What happens after the AG approves your AC installation?

Once you have the AG approval and the déclaration préalable has been accepted, work can start. A standard single-room split usually goes in within a day. A multi-split system serving several rooms takes longer and runs more pipes through the building, which may need extra paperwork.

Tell the syndic when the work is finished. Keep the extract of the minutes, the déclaration préalable acceptance and the signed handover record (PV de réception). The buyer's notaire will ask for them when you sell. Get the installer's warranty on the fitting and the manufacturer's warranty in writing too, because a unit added to an existing building isn't covered by the ten-year décennale insurance.

What pushes up the price of AC in an apartment building?

Height and access come first. An outdoor unit high up the facade may need scaffolding or a lift to reach it, and that can cost more than the unit. Ask how the fitter will get there and whether the devis includes it.

The pipe run is next. The further the outdoor unit sits from the indoor one, the more pipe, drilling and making good inside the flat. A multi-split serving two or three rooms runs a pipe to each, so ask where every one will go. Clean condensate drainage, often a condition of the vote, adds pipework too.

Get at least two written quotes for the same unit in the same position, so the AG dossier and the price match. Our AC installation cost guide covers what to look for in quotes.

More on AC units, permits and apartment rules

• Split AC installation on the Côte d'Azur
• Multi-split AC systems
• Déclaration préalable de travaux
• Devis: what your quote should contain
• Garantie décennale: what it covers and what it doesn't
• AC installation costs on the Côte d'Azur
• Planning permission for home energy work in France