Short answer. The whole of it, subject to three limits. A co-owner may use the common thing provided he keeps to the purpose it is intended for, does not injure the interest of the co-ownership, and does not stop the others from using it according to their rights. Shares are not zones.
What the law says
Each co-owner may use the thing owned in common, provided he does so in accordance with the purpose for which it is intended and in such a way as not to injure the interest of the co-ownership or prevent the other co-owners from using it according to their rights.
Civil Code, Article 486 — Use of the Common Thing. Read the full provision →
The right runs to the whole thing
Article 486 gives each co-owner the right to use the thing owned in common, without carving out a fraction for him. That follows from what a share is: an interest in every part of an undivided property rather than a claim to a particular part of it. A person with a quarter share is not confined to a quarter of the rooms. He may use the house, drive on the road, farm the land — and so may everyone else, at the same time, which is precisely the difficulty the rest of the sentence addresses.
The three conditions attached to it
First, the use must be in accordance with the purpose for which it is intended. A residential lot is not turned into a workshop by one co-owner's decision, though the article adds that the purpose may be changed by agreement, express or implied. Second, the use must not injure the interest of the co-ownership, which rules out anything that damages the property or its value. Third, and most often litigated, it must not prevent the other co-owners from using it according to their rights. Exclusive occupation is where the right stops.
Where families actually run into trouble
The common pattern is one heir living in the inherited house while the others live elsewhere. That is lawful in itself — his right extends to the whole property, and the others are not entitled to rent merely because they choose not to occupy it. It becomes unlawful when he shuts them out: changing the locks, refusing entry, treating the house as his own, or renting it to a stranger and pocketing everything. The line is not how much he uses but whether the others are excluded, and a co-owner who has been excluded has grounds the mere non-user does not.
How to fix it without going to court first
Most of these disputes come from the absence of anything written. Put the arrangement on paper while relations are still workable: who occupies what, who pays which expenses, whether rent is charged and how income is divided. If a co-owner is already excluding the others, make the demand for access in writing and keep it, because the date exclusion began matters more than any of the grievances that preceded it. And if the property can no longer be shared at all, the real remedy is partition — dividing the thing itself, which ends the problem the article is trying to manage.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Leonor B. Cruz vs. Teofila M. Catapang, G.R. No. 164110, February 12, 2008 — read the decision on LawPhil →
- Felicitacion B. Borbajo vs. Hidden View Homeowners, Inc., et al, G.R. No. 152440, January 31, 2005 — read the decision on LawPhil →