Acte de base and co-ownership regulations: reading and amending them

A service charge statement seems unfair to you. A neighbour wants to enclose their terrace. The meeting is considering selling a shared cellar. In all three cases, someone eventually says: ‘We need to look at the acte de base.’ So you dig out the notary’s file again, and you come across a dense text full of thousandths and unit numbers that you never really read when you bought.

Yet it is the document that brings the co-ownership into legal existence. Drawn up by a notary, often at the request of the developer or of the owner who divides up a building, the deed of division (acte de base / basisakte) describes what belongs to each owner and what belongs to everyone. It almost always comes with the co-ownership regulations, and the Civil Code calls these two texts together the articles of co-ownershipGlossaryThe deed of division and the co-ownership regulations taken together. They must be drawn up by authentic (notarial) deed, as must any amendment to them, and transcribed to be enforceable against third parties. See the glossary of the building. But they are not the last word. They sit within the legal framework of co-ownership set by the Civil Code, which takes precedence over them.

Acte de base, co-ownership regulations, house rules: three separate texts

The Civil Code requires three documents for every building under the co-ownership regime (Article 3.84): a deed of division, co-ownership regulations and house rules (ROI / RIO). The first two are notarial deeds. The third is not.

In practice, the deed of division and the co-ownership regulations are often combined in a single notarial deed. The house rules have their own page: house rules.

“The deed of division and the co-ownership regulations, which constitute the articles of the building or group of buildings, as well as any amendment made to them, must be the subject of an authentic deed.”

Art. 3.85, § 1, Civil Code

What does the acte de base contain?

Article 3.85, § 1, sets out its minimum content.

First you find the description of the property as a whole: the plot, the building or buildings, their floors. Then come the private parts, unit by unit (a third-floor apartment with cellar number 12, for example), and the common parts.

The heart of the deed is setting the share of the common parts attached to each private part. These shares (quotités)GlossaryFraction of the common parts attached to each unit, set in the deed of division according to the respective value of the private parts. Shares determine the number of votes at the general meeting and can only be changed with the unanimous agreement of all co-owners. See the glossary, often expressed in thousandths or ten-thousandths, are not chosen freely. The law requires account to be taken of the respective value of the units, determined on the basis of three criteria: net floor area, use and location of the private part. The calculation rests on a reasoned report drawn up by a notary, a surveyor, an architect or an estate agent.

Why does this matter to you? Because the share determines your number of votes at the general meeting (Article 3.87, § 6) and often serves as the basis for allocating charges. In practice, it is the first figure to look for in the deed, even before the description of your apartment.

Older deeds do not always have that reasoned report, and some shares were set according to other logics. If that is the case in your building and the gap has become obvious, for example after a shared attic was converted into an apartment, the route open to you is an action for correction before the court (Article 3.92, § 7), explained in the page on justice of the peace and co-ownership disputes.

What do the co-ownership regulations contain?

The co-ownership regulations have at least two parts.

The first describes each co-owner’s rights and obligations regarding the private parts and the common parts. This is where you will find, depending on the building, the ban on changing the appearance of the façades without permission, the rules on professional activities in an apartment, or the exclusive use of a shared garden.

The second part is about money: the reasoned criteria and the method for calculating the allocation of charges, and where applicable the clauses and penalties for non-payment. An allocation keyGlossaryCalculation rule that determines each unit's share of a category of charges: shares, metered consumption or another reasoned criterion. The criteria and the calculation method are set out in the co-ownership regulations. See the glossary may follow the shares for most expenses and use a different logic for the lift, which the ground floor does not benefit from, or for heating, split according to meters.

The co-ownership regulations cannot provide for everything. Two clauses are deemed unwritten by Article 3.85: one that limits your right to entrust the management of your unit to the person of your choice, and one that refers co-ownership disputes to arbitrators.

How do you amend the acte de base, and by what majority?

The procedure always follows the same path: a decision of the general meeting by the right majority, then a notarial deed, then registration. The majority depends on what is being changed (Article 3.88).

Majorities are calculated on the votes of the co-owners present or represented, not counting abstentions and blank or spoilt votes. Quorums and the calculation are set out in detail in the page on voting rules and majorities.

The unanimity required to touch the shares means all co-owners, not just those present. If it fails only because some are absent, the law provides for a new general meeting after a period of at least thirty days (Article 3.88, § 4).

The developer before provisional acceptance

As long as the common parts have not been provisionally accepted, those who signed the original articles can still amend them without a vote, provided this is justified by technical reasons or by the legitimate interest of the association, does not affect the rights of the other co-owners and does not increase their obligations. They bear the costs and must notify each co-owner by registered post at least two months before the amending deed is signed (Article 3.85, § 2).

Why registration changes everything

Signing at the notary’s is not enough. The articles and their amendments must be registered in the registers of the competent office of the General Administration of Patrimonial Documentation, which notaries call the Legal Certainty office.

This formality has two effects. On the one hand, it makes the articles enforceable against third parties. On the other, it determines the legal personality of the association: the owners’ association (VME/ACP) acquires legal personality only once joint ownership has arisen and the deed of division and co-ownership regulations have been registered (Article 3.86, § 1). As long as registration is missing, the association cannot rely on its legal personality against third parties, whereas they can invoke it against the association. The page on the owners’ association (VME/ACP) goes into this point.

The most common reading mistakes

First trap: believing that a decision of the meeting is enough. An amendment to the articles that was voted but never executed before a notary remains fragile, especially towards a buyer who never received it. Our view: a vote that affects the articles is only complete on the day the amending deed is registered, and you need to follow the file until then.

Second trap: reading the acte de base without its amending deeds. A unit divided in 2008, a cellar sold in 2015: each change was the subject of a separate deed. Ask the property manager (syndic) for the complete list.

Third trap: treating the description of the common parts as exhaustive. Where titles are absent or contradictory, the law deems common the parts of buildings or land intended for the use of all co-owners or some of them (Article 3.84). The page on private and common parts explains how to settle borderline cases such as window frames, balconies or pipes.

Last trap, for buyers: signing a sale agreement without having read the articles. You will be bound by them as soon as you become a co-owner. We advise nobody to buy an apartment without first looking up the unit’s share, its charge key and its restrictions on use. The documents to ask for before signing are listed in the page on documents required for a sale.