My neighbor's fence or house extension is built over our boundary line. What can I do?

Why

Boundary fights are won with documents, not with who has been there longest. Under Article 434 of the Civil Code, a person suing to recover property must identify it and rely on the strength of his own title. That means your certificate of title and its technical description, the approved survey plan, and a relocation survey showing where the corners and monuments (mohon) actually fall. For titled land, Section 47 of the Property Registration Decree (PD 1529) provides that no title to registered land can be acquired by prescription or adverse possession, so a neighbor's fence standing on your side for years does not make that strip his.

Do not tear down the fence yourself. Article 429 lets an owner use reasonable force only to repel an actual or threatened invasion as it happens. Once a structure is already standing, Article 536 requires anyone who claims a right to the property to go to court if the holder refuses to give it up. Article 430 does let you fence your own land, as long as you stay on your side of the line.

If you and your neighbor are individuals living in the same city or municipality, the dispute generally goes first to barangay conciliation, and under Section 409(c) of the Local Government Code (RA 7160) a dispute involving real property is brought in the barangay where the property, or its larger portion, is located. A written amicable settlement, for example agreeing to move the fence to the surveyed line, becomes as binding as a final judgment after 10 days unless repudiated.

If talks fail, the court case depends on timing. If the neighbor took the strip by force, intimidation, threat, strategy, or stealth, you may file forcible entry under Rule 70 of the Rules of Court within one year. After that, you file an action to recover possession (accion publiciana) or ownership (accion reivindicatoria). Under Batas Pambansa Blg. 129 as amended by RA 11576, these go to the first-level courts if the assessed value of the property is ₱400,000 or less, and to the Regional Trial Court if it is higher. If a document or claim casts doubt on your title, Article 476 allows an action to quiet title.

For a building already on your land, the Civil Code turns on good faith. If the neighbor built in good faith, you may either keep the structure after paying the indemnity under Articles 546 and 548, or make him buy the land it stands on; if the land is worth considerably more than the building, he pays reasonable rent instead (Article 448). If he built in bad faith, he loses what he built without indemnity, and you may demand its demolition at his expense or make him pay for the land, with damages (Articles 449–451). Under Article 453, you are considered in bad faith if the work was done with your knowledge and without your objection, so object in writing as soon as construction starts. Separately, moving or altering boundary marks is a crime under Article 313 of the Revised Penal Code, and taking someone's land by violence or intimidation is punished under Article 312.