Short answer. Absent a specific agreement, the local custom governs which repairs the landlord must pay for on urban rental property. If it is genuinely unclear what that custom requires, the law resolves the doubt against the landlord — the repairs are understood to be chargeable to them.
What the law says
In default of a special stipulation, the custom of the place shall be observed with regard to the kind of repairs on urban property for which the lessor shall be liable. In case of doubt it is understood that the repairs are chargeable against him.
Civil Code, Article 1686 — Repairs on Urban Property. Read the full provision →
A written or agreed stipulation controls first
Article 1686 opens with in default of a special stipulation — meaning the parties' own agreement about repairs comes first. If the lease itself spells out who handles which repairs, that agreement governs the arrangement, whatever it says. This article only steps in to fill the gap when the lease is silent on the question, not to override a clear contractual term.
Local custom fills the gap when the lease is silent
Where there is no special stipulation, the article looks to the custom of the place to determine the kind of repairs the landlord, or lessor, is liable for on urban property. This means the answer is not a single fixed national rule — it can vary depending on what is customarily expected of landlords in a given locality, so the same repair might be treated differently in different areas.
Genuine doubt is resolved against the landlord
If even the local custom leaves the matter genuinely unclear, Article 1686 breaks the tie in the tenant's favor: in case of doubt it is understood that the repairs are chargeable against him — meaning against the lessor. The default, where nothing else settles the question, leans toward putting the cost on the landlord rather than the tenant, rather than leaving the question unresolved. That default only fills a genuine gap — it does not override a local custom that clearly places a specific kind of repair on the tenant, since the doubt-resolution rule applies only once custom itself fails to settle the question.
What this means in a real dispute
If your lease does not address repairs directly, the first thing to establish is whether there is a recognizable local custom covering the specific kind of repair at issue. Only if that custom itself is unclear does the article's default rule apply, placing the burden on the landlord. This article addresses urban property specifically, and it does not spell out what counts as ordinary wear versus a repair in the first place, or how a local custom is to be proven.