What to do about hidden defects after buying a home

What is legally considered a hidden defect in a property?

A hidden defect is a serious and internal damage that is not apparent on a routine visit before formalizing the purchase. The law obliges the seller to be liable for these defects, even if he himself was completely unaware of them. By contrast, natural wear and tear of the property's materials is excluded from this legal coverage.

Three mandatory conditions to be able to claim

For a claim for hidden defects after buying a home to be accepted for processing, the fault must meet three strict requirements:

Seriousness of the damage: The defect must prevent normal habitation of the house or reduce its value to such an extent that, had you known, you would not have bought the property or would have negotiated a much lower price.

Preexistence: The damage must predate the signing of the sales contract, not a problem that arose later due to daily use.

Hidden nature: The defect must not have been visible. In addition, if the buyer is a professional in the sector (architect, building surveyor or builder), the law assumes they should have detected it due to their technical expertise.

Legal deadlines to claim these hidden defects

Time is against you from the very first moment. Do not let days pass relying only on an amicable verbal solution; deadlines vary drastically depending on whether the property is second-hand or a new-build development.

The six-month limit for second-hand properties

Article 1490 of the Civil Code sets a deadline of six months, counted from the delivery of the keys of the used property. Bear in mind that as it is an expiration period (plazo de caducidad) and not a statute of limitations, the time does not stop through the sending of letters or informal negotiations. You must file the lawsuit before the six months expire.

The Building Regulation Law for new-builds

If you are moving into a brand-new home, the Building Regulation Law (LOE) offers broader and staggered guarantee periods depending on the nature of the defect:

1 year: For failures or defects that directly affect the finishes and aesthetics of the work (paint, tiles or trims).

3 years: For defects that affect habitability or supply installations (dampness, failures in gas, electricity or water).

10 years: For serious structural damages that directly compromise the building's stability and safety.

The doctrine of "aliud pro alio" for extreme cases

What happens if the property turns out to be completely uninhabitable? When the defect is so colossal that the house is unusable, the courts apply the doctrine of aliud pro alio (delivering something different from what was agreed). This legal route is considered a pure breach of contract, which extends the judicial claim period up to five years.

Practical steps if you detect hidden defects after buying a home

If you encounter an unpleasant surprise in your new home, stay calm and follow a rigorous protocol. Acting methodically and with experts is the only guarantee to recover your money or force a flawless repair.

Hire a certified technical expert: the first step is to consult a registered architect or building surveyor. You need an official technical expert report that demonstrates the origin of the fault, its severity and the exact cost of its remediation. This document is your strongest piece of evidence in the judicial process.

Send a formal claim to the seller: with the expert report ready, you must notify the defects in writing and in a verifiable manner. Relying on specialists in legal services in Spain at this preliminary stage avoids formal mistakes and shields your legal strategy in view of a possible trial. The burofax (certified letter) will detail the damages with rigor, demanding an immediate response.

Choose between a price reduction or the return of the property

The law offers you two courses of action through the so-called building actions:

Estimatory action (quanti minoris): Allows you to keep the property while receiving a reduction in the price equivalent to the estimated cost of the repair.

Redhibitory action: Terminates the sales contract, allowing you to return the property and recover all the money invested, including notary and administrative fees.

Serious mistakes when claiming hidden defects after buying a home

Lack of familiarity with Spanish real estate law often leads to critical mistakes that ruin any possibility of compensation or indemnification.

Carrying out repairs before the technical expert carries out the inspection: repairing a leak or a break immediately for convenience is a serious legal mistake. If you fix the defects before the technical expert inspects and documents them photographically, you will destroy the physical evidence of the problem, making it impossible to prove that the damage already existed before signing.

Relying on a burofax to stop the clock of the law: many buyers assume that sending a burofax interrupts the deadline to sue for used homes, but the six-month expiration period does not stop by extrajudicial means. The preventive support of a trusted real estate agency on the Costa del Sol will help you carry out thorough inspections before you put your signature on the dotted line.

Discovering serious defects in your new home is complex, but the regulations protect your rights if you act quickly and with solid evidence. Do not let days pass waiting for informal agreements; secure every step by consulting technical and legal professionals with proven experience in the sector.