G.R. No. 100963 . April 6, 1993.
ARTEMIO SANTOS, PACENCIA REYES, CATALINA PASCUAL, TEODORA SANTOS, petitioners, vs. THE COURT OF APPEALS, HON. MARTIN S. VILLARAMA, JR. AND LOLITA DEOPANTE VDA. DE SAAVEDRA, respondents.

FACTS

In July 1951, Margarita Tuason leased a parcel of land to Fortunato H. Santos (predecessor-in-interest of petitioners) for three years at a monthly rental of P35.00. Fortunato built a residential house and a barber shop on the land. After Margarita Tuason’s death in 1952, Fortunato continued possession with the acquiescence of successor-in-interest Asuncion Tuason at an increased rental of P65.00. Asuncion Tuason later conveyed the property to private respondent Lolita Deopante Vda. de Saavedra. An ejectment case filed by private respondent against Fortunato in 1961 was dismissed. Upon Fortunato’s death, petitioners continued possessing the premises but failed to pay rentals from March 1961 to November 1989. Private respondent filed an ejectment case. The Metropolitan Trial Court declared petitioners in default and ordered them to vacate, pay unpaid rentals of P22,425.00, and pay monthly compensation until vacation. On appeal, the Regional Trial Court affirmed the decision but added an order for private respondent to reimburse petitioners for the improvements introduced by Fortunato. Petitioners appealed to the Court of Appeals; private respondent did not appeal. The Court of Appeals modified the RTC decision by eliminating the reimbursement order. Petitioners filed this petition.

ISSUE

1. Whether the Court of Appeals erred in passing upon the issue of reimbursement for improvements, which was not raised in the petition for review.
2. Whether the Court of Appeals erred in giving affirmative relief to private respondent who did not appeal the RTC decision.
3. Whether the Court of Appeals erred in affirming the RTC’s finding that petitioners are obligated to pay the rentals.

RULING

1. No. While the general rule is that a party cannot impugn a judgment not appealed from, the Rules of Court and jurisprudence authorize a tribunal to consider unassigned errors if they involve: (a) errors affecting jurisdiction over the subject matter, (b) plain errors not specified, or (c) clerical errors. The RTC’s award of reimbursement for improvements constituted a plain error. A lessee, being a lawful possessor by virtue of a lease contract but not a possessor in good faith, is not entitled to reimbursement or retention rights as a possessor in good faith. His rights are governed by Article 1678 of the Civil Code, which allows reimbursement only at the option of the lessor for one-half the value of useful improvements made in good faith. The lessee cannot compel reimbursement; his right is to remove the improvements. Therefore, the Court of Appeals correctly rectified this plain error.
2. No. The principle that a party who does not appeal may not obtain affirmative relief is subject to the exceptions stated above. Since the reimbursement award was a plain error, the Court of Appeals was authorized to modify the judgment by eliminating it, even though private respondent did not appeal.
3. No. The factual finding of the lower courts, that petitioners enjoyed possession of the property with their father and continued after his death, is binding. Petitioners’ contention that the unpaid rentals were incurred by Fortunato Santos alone is without merit. As they continue to occupy and derive benefit from the property, the principle against unjust enrichment applies: “Nemo cum alterius detrimento locupletari potest” (No one shall enrich himself at the expense of another). Thus, they are liable for the unpaid rentals.
The decision of the Court of Appeals is AFFIRMED in toto.