If my neighbor never objects to a window I opened facing their property, when does the countdown start toward me acquiring a permanent right to keep it?

Two starting points, not one

Article 668 does not set a single trigger for when the prescriptive period begins. It sets two, depending on the kind of wall the window passes through: from the time of the opening of the window, if it is through a party wall, or from the time of the formal prohibition upon the proprietor of the adjoining land or tenement, if the window is through a wall on the dominant estate. Which one applies to your situation depends entirely on which wall the window is in.

A party wall: the clock starts when you open it

Where the window is opened through a party wall — a wall shared between the two properties — the period is counted from the moment the window was actually opened. No further step by the window's owner is needed to start the clock in this scenario; the act of opening the window is itself what Article 668 treats as the starting point.

Your own wall: silence alone does not start anything

Where the window is instead opened through a wall on the dominant estate — meaning your own property, not a shared wall — the rule is different. The period does not begin merely because the window exists or because your neighbor has said nothing about it. It begins only from the time of the formal prohibition upon the proprietor of the adjoining land — that is, from a formal objection made by the adjoining owner, not from your neighbor's silence.

Why the wall matters so much here

For a window through your own wall, your neighbor's continued silence does not, by itself, start the countdown Article 668 describes — the article ties that clock to the formal prohibition, an act by the neighbor, rather than to inaction. Anyone in this situation should first establish which kind of wall the window actually passes through, since that single fact determines which of the two starting points in this article applies to them.

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.

• Sps. Tedy Garcia and Pilar Garcia vs. Loreta T. Santos, Winston Santos and Conchita, G.R. No. 228334, June 17, 2019 — read the decision on LawPhil →

Related provisions

• Civil Code, Article 668 — When Light-And-View Prescription Starts