Undivided co-ownership
A co-ownership is “undivided” when several people own an immovable that is not divided into distinct lots as they are in the case of a divided co-ownership.
None of these owners (called “undivided owners”) owns a private portion of the immovable, but all own a percentage of the entire immovable and have exclusive rights of use thereof. The immovable’s common expenses, including municipal and school taxes, are shared by all co-owners based on the respective share they own.
A triplex in which the members of one family have invested (whether or not they reside there) is a good example of an undivided co-ownership property. Each owner owns a percentage of the immovable, which does not necessarily correspond to one of the building’s dwellings.
Undivided co-ownership arises without formality when several persons acquire a single property. However, it is in their interest to establish a written agreement between them, normally called an “indivision agreement.” This agreement normally states the term of the agreement, the rights and obligations of the undivided co-owners with respect to enjoyment of the premises, sharing of maintenance and repair obligations, sharing of expenses, restrictions on the sale, administration of the property, etc. An indivision agreement must be renewed every 30 years. To be enforceable against third parties, it must be published in the Land register.
For more details: Divided or undivided co-ownership: Do you know the difference?