10-Year Structural Warranty in Spain: The Guarantee Behind Every New Build

What protection do you have if structural problems emerge in your property five years after you buy it? If your answer is "I'm not sure" — you're not alone. Most international buyers on the Costa Blanca have never heard of the seguro decenal, the mandatory ten-year structural warranty that attaches to every new build property in Spain. When they find out it exists, the next question is usually the same: why didn't anyone mention this sooner?

What Buying Resale Actually Means for Your Risk Profile

Resale properties are presented as the safer, more tangible choice. You can see the property. You can walk through it. There are no surprises — or so the thinking goes.

What you're actually buying with a resale property is the accumulated history of a building. Decades of structural loading, weather exposure, previous owners' modifications, and maintenance decisions you know nothing about. The survey — if you commission one — gives you a snapshot. It can't tell you what's developing inside a wall, beneath a floor, or within a foundation.

A structural defect that takes years to manifest visibly can be present and progressing long before anyone sees it. And when it does appear in a resale property, the liability question becomes complex, contested, and expensive. There is no automatic protection. There is no warranty. There is litigation.

New build in Spain is legally different. Not because developers don't make mistakes — they do — but because when they do, the law requires them to have insured against it on your behalf.

What the 10-Year Structural Warranty Actually Is

The 10-year structural warranty (known in Spanish as the seguro decenal) is a mandatory insurance policy that every developer must obtain before construction begins on a new build property in Spain. It is required under the Ley de Ordenación de la Edificación (LOE), passed in 1999. It cannot be waived. It cannot be substituted. The property cannot be registered in your name at the notary without it.

The policy covers structural defects — problems affecting the foundations, load-bearing walls, beams, and structural elements that compromise the stability or habitability of the building. If a covered structural defect emerges within ten years of completion, the insurance responds. Not the developer, not the previous owner, not you: the insurance policy.

This matters enormously. A developer who went into administration two years after delivering your property is not a developer you can pursue. The insurance policy exists precisely to make the recourse independent of whether the developer is still solvent and accessible.

The Three-Layer Warranty System

The 10-year structural warranty sits at the top of a tiered system of protections that applies specifically to new build properties in Spain. Understanding all three layers gives you a complete picture of what you're protected against and for how long.

One Year: Finishing Defects

The first year after completion, the developer carries liability for finishing defects — tiles that crack, paintwork that fails, carpentry that doesn't align, fixtures that don't function as specified. These are the snag list items: the visible, surface-level issues that appear as a new building settles and its occupants start living in it. The developer is responsible for rectifying these defects at their cost within the first twelve months.

Three Years: Habitability Defects

For three years, the developer carries liability for defects that affect habitability — waterproofing failures, insulation problems, HVAC system deficiencies, and other issues that make the property uncomfortable or unfit for its intended use without rising to the level of structural failure. These defects are less visible than snag list items but more serious, and the three-year window gives buyers time to identify problems that only become apparent through a full seasonal cycle.

Ten Years: Structural Defects

This is the 10-year structural warranty's domain. For a full decade from the certificate of completion, the insurance policy covers structural defects that affect the stability or structural integrity of the building. Foundations, structural walls, frames, beams, slabs — if any of these fail or develop defects that compromise the building's structural integrity, the claim goes to the insurer. This protection transfers with the property; if you sell during the ten-year period, the remaining coverage passes to the next owner.

What the 10-Year Structural Warranty Does Not Cover

The policy is specific in its scope. It covers structural defects. It does not cover:

• Cosmetic or aesthetic issues — these fall under the one-year finishing defect liability, not the ten-year insurance.
• Equipment and appliance failures — white goods, air conditioning units, and installed appliances carry their own manufacturer warranties.
• Damage caused by the owner — modifications, poor maintenance, or misuse after handover are outside the policy's scope.
• Non-structural building elements — cladding, roofing tiles, or external finishes that fail for reasons unrelated to structural integrity are typically addressed under the shorter-term developer liability periods.

The policy is also only as good as the insurer behind it, which is why your independent lawyer verifies its existence and terms as part of the purchase process. It should be referenced in the private purchase contract and confirmed before completion.

The Comparison That Makes the Case

Resale properties in Spain carry none of this. An older resale may have had a 10-year structural warranty when it was originally built — but that policy expires ten years after completion, and most resale properties on the market are well beyond that window. You are buying with no structural warranty, no habitability protection, and no finishing defect coverage. Whatever condition the property is in on the day you take ownership is what you own, problems included.

This is not an argument that resale is always the wrong choice. Some buyers have specific reasons for preferring it. But the comparison should be honest: new build in Spain comes with legal protections that resale cannot match. That protection has real value, and it's built into the price you're already paying. You're not paying extra for it. It's there because the law requires it.

If you're comparing new build and resale options on the Costa Blanca, our guide to new build versus resale covers the full picture — quality, price dynamics, legal structure, and the long-term case for each.

Browse the new build properties currently available to see developments where the 10-year structural warranty is active and the full warranty layers apply from the day you receive the keys.

If you have questions about what the warranty covers on a specific development, or want to understand how it fits into the broader protections on a purchase you're considering, we're available in the chat. It's a specific question that deserves a specific answer.

Frequently Asked Questions

What is the 10-year structural warranty in Spain?

The 10-year structural warranty (called the seguro decenal in Spanish) is a mandatory insurance policy that every developer must obtain before constructing a new build property in Spain. It is required by law under the Ley de Ordenación de la Edificación (1999). It covers structural defects affecting the stability or habitability of the building for ten years from the certificate of completion, and cannot be waived or transferred away from the policy.

Is the 10-year structural warranty the same as a building warranty?

It functions similarly to a structural building warranty in other markets, but it is mandatory rather than optional and is backed by insurance rather than just a developer's promise. The policy remains valid even if the developer goes out of business, which is its primary practical advantage over a simple contractual warranty.

Does the 10-year structural warranty transfer to a new owner if the property is sold?

Yes. The remaining coverage transfers with the property when it is sold. If a new build is sold five years after completion, the buyer benefits from the remaining five years of structural protection under the original policy.

Do resale properties in Spain have a 10-year structural warranty?

Properties built after 2000 may have had a 10-year structural warranty when originally constructed, but the ten-year period will have expired for most resale properties on the market. Properties built before 2000 were not subject to the mandatory requirement. In either case, a resale buyer is not protected by an active policy.

What should my lawyer check about the 10-year structural warranty before I complete?

Your independent lawyer should confirm that a valid 10-year structural warranty policy exists, identify the insurer, verify the coverage start date (which should align with the building's completion certificate), and ensure the policy reference is included in the title deed. This verification is a standard part of the pre-completion legal review for any new build purchase in Spain.