Unauthorized construction on another person’s land usually falls into one (or more) of these situations:

A person builds entirely on land they do not own (a “builder on another’s land” problem under the Civil Code rules on accession).
A person’s structure encroaches across a boundary (a partial encroachment/boundary dispute).
A person builds while their right to possess has ended (e.g., expired lease, cancelled sale, terminated tolerance).
A person builds without permits or in violation of zoning/building regulations, even if they claim some right (administrative enforcement).

Philippine law gives the landowner (and sometimes the builder) a menu of civil, possessory, administrative, and occasionally criminal remedies. The correct remedy depends heavily on good faith vs. bad faith, the nature of possession, and whether the land is titled/registered.

I. Core Legal Framework: Accession and “Builder in Good Faith” Rules

A. The principle of accession

As a general rule, whatever is built on land belongs to the landowner as an incident of ownership (accession). But the Civil Code qualifies this when the builder and landowner are different persons—especially when the builder acted in good faith.

B. The key distinction: Good faith vs. bad faith

In this context:

Builder in good faith: one who builds believing they have a right to build—typically because they honestly think they own the land or have authority (e.g., deed/sale they believe valid, inherited property they believe includes the area, boundary mistake based on markers/survey).
Builder in bad faith: one who builds knowing the land is not theirs or knowing their right is disputed/defective but proceeds anyway; or continues building after clear notice/objection, depending on circumstances.

Good faith is fact-sensitive and can change over time (e.g., good faith at the start, then bad faith after notice).

II. Civil Code Remedies When Someone Builds on Another’s Land

These are mainly governed by the Civil Code provisions on builders/planters/sowers and useful expenses.

A. If the builder is in good faith: the landowner generally must choose between two options

Where a person builds in good faith on another’s land, the landowner is typically given an election:

Appropriate the building/improvement, after paying indemnity (compensation) to the builder; or
Compel the builder to purchase the land on which the building stands, unless the value of the land is considerably more than the value of the building (in which case, the builder may instead be required to pay reasonable rent if the landowner does not choose appropriation).

Indemnity commonly includes the value of the building and/or the necessary and useful expenses, depending on classification and proof.

1) What the landowner cannot usually do against a good-faith builder

If the builder is truly in good faith, the landowner generally cannot automatically demand demolition at the builder’s expense as the first and only remedy. The policy is to avoid unjust enrichment and to balance equities.

2) Builder’s retention right

A good-faith builder may have a form of right of retention—the ability to remain in possession of the portion affected until the landowner pays the proper indemnity (subject to court supervision and equities).

B. If the builder is in bad faith: the landowner’s remedies become harsher

If the builder is in bad faith, the landowner typically may:

Demand demolition/removal of the building at the builder’s expense, and restoration of the land; and/or
Appropriate the building without paying indemnity (subject to rules on damages and equitable considerations), plus
Recover damages.

Bad faith significantly strengthens claims for demolition, damages (including consequential damages), attorney’s fees where justified, and injunctive relief.

C. Mixed good faith/bad faith scenarios

Philippine law also recognizes combinations, such as:

Builder in good faith, landowner in bad faith (e.g., owner watches silently then pounces). Courts may treat the landowner as having acted inequitably, affecting available relief and liability for damages.
Both in bad faith (rare but possible in collusive or knowingly risky setups).

Because these are equity-heavy, outcomes can vary depending on proven conduct (notice, objections, negotiations, delay, tolerance).

III. Encroachment and Boundary Situations (Partial Intrusion)

Many “unauthorized construction” cases are actually boundary encroachment cases (a wall, extension, eaves, fence, or part of a house crosses the line).

A. Practical legal characterizations

Encroachment disputes often involve:

Accession principles (if a portion of a building is on another’s land),
Property and boundary determination (survey, relocation survey, technical descriptions),
Easements (e.g., illegal encroachment into easement areas, right-of-way issues),
Nuisance (if the structure creates danger, obstruction, or unlawful interference).

B. Typical judicial outcomes

Courts may order:

Removal/demolition of the encroaching portion (especially when bad faith is proven, or where public policy/safety requires),
Payment of indemnity and/or forced sale options under good-faith rules,
Damages for loss of use, impairment, or rental value.

C. Evidence is decisive

Boundary cases rise and fall on:

Title technical descriptions,
Approved subdivision plans,
Relocation surveys by geodetic engineers,
Monument/marker history,
Possession history and improvements.

IV. Possessory and Ownership Actions in Court (Choosing the Right Case)

Unauthorized construction usually comes with unauthorized possession. Philippine procedure divides property disputes into actions based on possession vs. ownership, and on timing.

A. Summary ejectment: Forcible entry and unlawful detainer (MTC)

These are speedy remedies where the main issue is physical/material possession (possession de facto), not ownership.

Forcible Entry: defendant entered/occupied by force, intimidation, threat, strategy, or stealth.
Unlawful Detainer: defendant’s possession was initially lawful (lease, tolerance, permission) but became illegal upon expiration/termination and refusal to leave.

Key feature: generally must be filed within 1 year from:

For forcible entry: from actual entry (or discovery if by stealth, under many fact patterns).
For unlawful detainer: from last demand to vacate or from end of right (fact-specific).

If construction is ongoing, ejectment can be paired with injunctive relief to stop further building.

B. Accion publiciana (RTC or MTC depending on jurisdiction rules)

If more than one year has passed but the dispute is still essentially about better right to possess, an ordinary civil action for recovery of possession (accion publiciana) is used.

C. Accion reivindicatoria (recovery of ownership) and related actions (RTC or MTC depending on assessed value)

If the landowner seeks to recover ownership (and possession as a consequence), the proper remedy is an action to recover ownership (accion reivindicatoria), often with:

Damages,
Removal/demolition,
Quieting of title or reconveyance (if title issues exist).

D. Quieting of title / reconveyance / annulment of documents

If the builder claims ownership through documents (deeds, tax declarations, questionable titles), the landowner may need additional causes of action:

Quieting of title (to remove a cloud),
Reconveyance (when property is registered in another’s name through fraud/mistake and the land is still identifiable),
Annulment of deed/title-related instruments (where applicable).

E. Provisional remedies: stopping construction now

If urgent, landowners commonly seek:

Temporary Restraining Order (TRO) and Preliminary Injunction to stop construction or prevent further encroachment,
In extreme cases, receivership or other measures, though less common in pure boundary disputes.

Courts look for: clear right, urgent necessity, and serious damage if construction continues.

V. Demolition: When and How It Becomes Available

A. Demolition as a civil remedy

Demolition may be ordered:

When the builder is in bad faith,
When the structure is a continuing trespass and equity supports removal,
When it violates legal setbacks/easements or endangers safety,
When the landowner elects remedies consistent with the Civil Code and the facts justify it.

Courts generally avoid demolition against a proven good-faith builder if statutory options require indemnity/forced sale/rent, but encroachment facts and public policy violations can change the equation.

B. Demolition as an administrative remedy

Even if civil ownership is disputed, a structure may be subject to administrative action when it violates building laws (see next section).

VI. Administrative and Regulatory Remedies (Permits, Zoning, Building Code)

Unauthorized construction often involves:

No building permit,
No occupancy permit,
Violations of zoning ordinances,
Encroachment into easements/road right-of-way,
Construction on land without owner’s consent (a common permit requirement).

A. Local government enforcement

City/municipal building officials typically have authority to:

Issue stop-work orders,
Cite violations,
Require compliance/rectification,
Recommend or implement demolition in serious violations, following legal procedures.

B. Strategic value

Administrative remedies can be faster for stopping ongoing work, but they do not finally resolve ownership. They are best used alongside civil actions when:

Construction is ongoing and urgent,
The builder cannot produce permits/consents,
The structure violates setbacks/easements.

VII. Damages and Monetary Claims Available to the Landowner

Regardless of the main remedy, landowners often claim:

Actual damages: cost of repair/restoration, survey costs, legal expenses where recoverable, loss of income.
Reasonable rental value / mesne profits: compensation for loss of use of the land occupied.
Moral damages: possible in specific circumstances where bad faith, fraud, or oppressive conduct is proven and the law allows.
Exemplary damages: when defendant acted in a wanton, fraudulent, reckless, oppressive manner.
Attorney’s fees: not automatic; allowed only under recognized circumstances (e.g., bad faith, compelled litigation, etc.).

Landowners should preserve proof: demand letters, photos, drone imagery where lawful, engineering estimates, rental comparables, and survey reports.

VIII. Criminal Law Angles (Limited but Sometimes Relevant)

Unauthorized construction is primarily a civil matter, but criminal liability may arise in specific fact patterns, such as:

Usurpation of real rights/property (certain forms of occupation or taking of real property rights under the Revised Penal Code), depending on the manner of occupation and intent.
Malicious mischief or other property-related crimes if the builder damages property, destroys boundaries, or alters markers.
Falsification or use of falsified documents if permits, deeds, or authorizations are forged.

Criminal complaints are not substitutes for proper civil actions; they may, however, add leverage where clear criminal elements exist.

IX. Special Issues That Often Decide Cases

A. Registered land vs. unregistered land: effect on prescription

For registered land (Torrens title), ownership is strongly protected; acquisitive prescription generally does not defeat the registered owner’s title.
For unregistered land, long, uninterrupted, adverse possession may create complex disputes over ownership and rights—though the specific outcome depends on character of land, possession, and proof.

B. “Tolerated” possession and the timing trap

If a landowner “allows” a builder to stay temporarily and later wants them out, the case may shift toward unlawful detainer and demand-to-vacate requirements, with strict timing rules.

C. Co-ownership and family property disputes

A frequent scenario: one heir builds on property claimed to be “theirs,” but the land is still co-owned. Remedies differ:

Co-owner rights to possess exist, but building without consent may trigger accounting, reimbursement rules, partition issues, and bad faith findings depending on conduct.

D. Builders who are lessees, buyers under a failed sale, or mortgagees in possession

If the builder initially entered lawfully (lease, contract to sell, conditional sale), remedies may involve:

Contract enforcement/rescission,
Unlawful detainer after termination,
Reimbursement rules for useful improvements under obligations/contract law in addition to accession.

X. Practical Litigation Roadmap (Philippine Setting)

Step 1: Establish the boundary and ownership evidence

Gather title documents, tax declarations (secondary), subdivision plans, and commission a relocation survey.

Step 2: Put the builder on formal notice

Written demand to stop, vacate, and/or remove encroachments; reserve rights and state that continued construction is in bad faith.

Step 3: Choose the primary action correctly

Within 1 year and possession-focused: ejectment in MTC.
Beyond 1 year, possession-focused: accion publiciana.
Ownership-focused or title disputes: reivindicatoria/quieting/reconveyance.
Ongoing construction: add injunction requests.

Step 4: Consider parallel administrative enforcement

If no permits or clear code violations exist, pursue local building official action to stop work.

Step 5: Align requested relief with Civil Code elections

If builder plausibly acted in good faith, plead remedies consistent with the landowner’s election (appropriation with indemnity vs. compel purchase/rent), plus damages where proper.
If bad faith is strong, plead demolition/removal plus damages.

XI. What “All There Is to Know” Really Means in Practice

Unauthorized construction disputes are a blend of:

Substantive property rules (accession; good/bad faith),
Procedural strategy (correct action, timing, jurisdiction),
Evidence engineering (surveys, plans, technical descriptions),
Equity factors (notice, conduct, delay, tolerance),
Regulatory overlays (permits, zoning, easements),
Remedial design (indemnity, forced sale, rent, demolition, damages, injunction).

The most outcome-determinative issues are typically:

Who can prove the true boundary and better right (technical evidence),
Whether the builder is in good faith or bad faith, and when that changed,
Whether the case was filed under the correct cause of action within required periods, and
Whether the land is registered and what the title and plans actually cover.