Subdivision of a Condominium Unit: Disappearance and Replacement of the Initial Unit

Imagine: you own a large flat in Créteil, in a 1970s condominium. To deal with financial difficulties, you decide to divide it into two independent studios. You sell one, keep the other. Everything seems simple. But a year later, the managing agent demands condominium charges calculated as if your unit had never been divided. How is that possible?

This situation, more common than one might think, raises a fundamental legal question: what happens to a condominium unit when it is subdivided? Does it disappear entirely? Or does it continue to exist, with unchanged rights and obligations?

The Court of Cassation, in a judgment of 22 February 1989 (No. 87-14.841), decided: the subdivision of a unit entails the modification of its constituent elements, therefore its disappearance and its replacement by the new units resulting from the division. A decision with immediate practical consequences, which we will analyse.

The facts: a story that happens every day

The case begins in Paris. The company Paul Garboua immobilier acquires, in a condominium building, a unit consisting of several rooms. The condominium regulations, drafted in the 1960s, describe this unit as a single entity, with a share of common parts and a specific allocation of charges.

A few years later, the company decides to divide this unit into several separate flats. It sells these flats to different buyers. So far, nothing unusual: the subdivision of a unit is a common operation, especially in large cities like Paris or Créteil, where demand for small homes is high.

But the condominium association disagrees. It considers that the subdivision was not properly authorised by the general meeting, and that charges must continue to be allocated as if the initial unit still existed. The Garboua company, for its part, argues that subdivision is a right of the owner, and that the new units must be treated independently.

The dispute goes up to the Paris Court of Appeal, which rules in favour of the association. The company appeals to the Court of Cassation. The Court of Cassation must decide: is the subdivision of a unit a mere physical division, or a legal modification that causes the initial unit to disappear?

The reasoning of the court — analysed

The Court of Cassation relies on Articles 1 and 11, paragraph 2, of the Law of 10 July 1965 (the Condominium Law). Article 1 defines the condominium unit as a right of ownership over a private part, together with a share of the common parts. Article 11, paragraph 2, provides that in the event of a separate disposal of one or more fractions of a unit, the allocation of charges between those fractions must be fixed by the condominium regulations or, failing that, by a decision of the general meeting.

In other words, when a unit is divided, new private parts are created, and therefore new units. Each of these new units has its own share of common parts, which must be determined. The initial unit no longer exists: its constituent elements (private part and share) have been modified.

The Court specifies that this modification cannot be done without complying with the condominium rules. In particular, if the condominium regulations do not provide for the method of allocating charges in the event of division, the general meeting must vote on a new allocation. Failing that, the division is irregular and the initial unit continues to exist legally.

In clear terms, the Court of Cassation confirms that the subdivision of a unit is not a trivial act: it is a legal operation that modifies the very structure of the condominium. The judges reject the argument of the Garboua company, which considered that subdivision was a mere right of the owner. They recall that the condominium is a collective organisation, and that any division must be accepted by the community of co-owners.

What few people know is that this decision fits into a logic of protecting co-owners. If subdivision were free, an owner could divide their unit into several micro-units, unilaterally changing the allocation of charges and voting rights. The Court of Cassation puts an end to this potential abuse.

What this changes for you — practically

This decision has important practical consequences for all actors in the condominium. Let's look at them profile by profile.

For the landlord owner who wishes to subdivide a unit: you must absolutely obtain the agreement of the general meeting of co-owners to fix the new allocation of charges. Failing that, your division will be contestable, and the new units will not be legally recognised. Concrete example: in Pontoise, an owner divides a 100 m² unit into two 50 m² studios. Without a vote of the meeting, the managing agent can continue to demand charges based on the initial unit, i.e. 100 m². Result: the owner pays twice as much as they should.

For the buyer of a unit resulting from a division: beware! Check that the division was properly approved by the general meeting. If not, you risk finding yourself in a situation where your unit does not exist legally. Charges could be claimed from you as if you were still the owner of a fraction of the initial unit, with random shares.

For the condominium managing agent: this decision gives you a tool to require owners to regularise unauthorised divisions. You must ensure that any division is accompanied by a modification of the condominium regulations and a new allocation of charges voted at the meeting.

For the co-owner who suffers a division in their building: you can challenge an unauthorised division. Indeed, a division changes the balance of charges and voting rights. If you notice that a neighbour has subdivided their unit without authorisation, you can apply to the judicial court to have the division annulled and the initial state restored. However, beware: the limitation periods (5 years from the division) must be monitored.

undefined, I have encountered cases where owners had subdivided a unit into several studios without any formalities. The managing agent, powerless, continued to claim charges from the former owner, who could not recover them from the tenants. An inextricable situation, which could have been avoided by a simple prior consultation.

Four tips to avoid this type of dispute

• Consult the condominium regulations before any division: check if they contain clauses relating to the subdivision of units. Some regulations simply prohibit division, or subject it to strict conditions (minimum area, etc.).
• Have a modification of the condominium regulations voted: before dividing, convene a general meeting to have the new allocation of charges and the creation of the new units approved. Obtain the required majority vote (generally the majority under Article 26 of the 1965 Law, i.e. two-thirds of the votes).
• Call in a surveyor-expert: to subdivide a unit, it is essential to know precisely the areas and the shares of common parts. A surveyor can draw up a descriptive statement of division, which will serve as a basis for modifying the regulations.
• Register the division with the land registry: once the division is approved, have the amending deed published with the land registry service. This will make the division enforceable against third parties (future buyers, banks, etc.).

Further study: related case law and developments

This 1989 judgment is part of a line of decisions that strengthen collective control over modifications of units. Before this date, some lower courts considered that subdivision was an individual right of the owner, as long as it did not harm the rights of other co-owners. The Court of Cassation put an end to this uncertainty.

Since then, other decisions have clarified the consequences. For example, a 1995 judgment (No. 93-20.111) held that the division of a unit without modification of the condominium regulations is a violation of the law, and that the new units cannot be sold separately until the regularisation is carried out. More recently, the Court of Cassation recalled that the allocation of charges between the units resulting from the division must be fair, failing which it may be annulled for abuse of majority (Cass. 3rd Civ., 12 June 2012, No. 11-17.352).

The trend is therefore clear: courts are becoming stricter about division formalities. In the future, one can expect judges to require not only a vote of the meeting, but also an impact study on charges and voting rights. For condominiums, this is a guarantee of transparency and fairness.

In practice: what to do

FAQ - Frequently asked questions about subdivision of a unit

1. Can I subdivide my unit without the agreement of the general meeting? No, not if you want the division to be legally valid. Without agreement, the initial unit continues to exist and charges remain unchanged.
2. What majority is required to approve a division? In principle, the majority under Article 26 of the 1965 Law (two-thirds of the votes of all co-owners). But check your regulations: they may provide for a different majority.
3. What if my neighbour subdivides their unit without authorisation? You can apply to the judicial court to have the division annulled and the initial state restored. You have 5 years from the division to act.
4. How much does it cost to regularise a division? Costs vary: surveyor's fees (€1,000 to €3,000), notary fees for the amending deed (€500 to €1,500), possible lawyer's fees (€1,500 to €5,000 depending on complexity). Better to anticipate than to regularise.
5. Can I subdivide a unit for short-term furnished rental (like Airbnb)? Yes, but the same rules apply. Moreover, some condominiums prohibit short-term furnished rentals in their regulations. Check before dividing.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →