Do I need a lawyer to make a claim against the decenal insurance, or can I contact the insurer myself?

You can contact the insurer directly, but a lawyer or an independent technical expert makes a claim like this much stronger, because the insurer wants a clear technical basis for classifying the damage as structural rather than a lesser category. For anything beyond a minor, obvious case, the cost of that expert opinion is usually small compared to what a structural claim is worth.

If I bought a new build and the ten-year structural warranty has not yet expired, does it matter that I am not the original buyer?

No. The seguro decenal attaches to the building itself, not to the person who first bought it. So a later owner who buys within the original ten-year period inherits the same cover for whatever time remains. This is worth confirming specifically when buying a fairly new resale property still inside its original ten-year window, since it is a real, transferable asset of the property.

On a resale property, is a defect the previous owner simply did not know about treated the same as one they hid on purpose?

No, and this is the central difficulty of a vicios ocultos claim. The seller only answers for a defect they really knew about and hid, not for one that existed without their knowledge. This is a real, meaningful right, but proving what someone else knew is a much harder task than pointing to a statutory warranty period. This is exactly why the pre-purchase inspection matters more on a resale property than on a new build.

Guides

A defect appeared after handover: who is responsible and until when

In 30 seconds

A Spanish new build carries three separate warranty periods: one year on finishes, three on installations, ten on structure. A different set of building agents answers for each. The ten-year cover is compulsory insurance, and it survives the builder going out of business. A resale property carries none of this. It has only a six-month hidden-defects claim.

All the protection a new build carries, at a glance

People talk about "the warranty on a new build" as if it were one thing, with one length. It is really five separate mechanisms. They protect different things, and different parties owe them. Only some of them survive the company that built the property going out of business. This page shows the whole set in one place, with a link to the page that explains each one in full.

Handover10 years

Finishes1 year
Habitability3 years
Structure10 years
Resale properties hidden defects6 months

6 months: The whole resale property window, drawn on the same scale

A resale property’s 6-month window is a fraction of even the shortest new-build warranty.

Layer	When it runs	What it protects, and who owes it
Bank guarantee (aval bancario)	From your first off-plan payment until the property is delivered.	Your money, not the building. This covers every amount paid to the developer before completion, tax included, plus statutory interest. It is returned to you if the property is never delivered. A bank or an insurer owes it, never the developer itself.
Handover and the defects list	One day: the signature at the notary. Every clock below starts here.	Nothing by itself, which is exactly why it matters. The defects list agreed on that day is the evidence used months later to argue the one-year warranty. The developer owes the fixes listed on it.
1 year, execution defects	One year from completion.	Finishing work: paintwork, tiling, fittings, anything cosmetic or superficial to the finished work. The constructor alone answers for it.
3 years, habitability defects	Three years from completion.	Plumbing, electrics, insulation, waterproofing: failures that leave the property short of basic habitability requirements. The constructor, and in practice whichever installer did the failing work.
10 years, structural defects	Ten years from completion.	Foundations, supports, beams, floor slabs, load-bearing walls. The developer, the architect, the site-supervising technician and the constructor together, jointly and severally where the cause cannot be isolated to one of them.
Seguro decenal	The same ten years, but it does not depend on anyone still trading.	The compulsory insurance that stands behind the ten-year structural warranty. The claim runs against the insurer, not the builder, so it survives that company closing, merging, or going insolvent. It stays with the building and carries over to the next owner.

Position as of August 2026. The three tiers and the joint-and-several rule come from LOE article 17. The compulsory decenal insurance comes from article 19. The payment guarantee comes from the same law's first additional provision, as rewritten by Ley 20/2015. A second-hand property carries none of these. Instead, it carries the six-month hidden-defect claim set out further down.

Sources

Who answers when something breaks after you move in?

The familiar summary, ten years for the structure, three for installations, one for finishes, states how long each warranty lasts. It rarely states who you should contact when something in one of those categories fails, and the answer is not the same person every time.

	1 yearExecution defects	3 yearsHabitability defects	10 yearsStructural defects
What it covers	Finishing work: paintwork, tiling, fittings	Plumbing, electrics, insulation, waterproofing	Foundations, supports, beams, load-bearing walls
Who answers for it	The constructor alone	The constructor and the relevant installer	The full set of building agents, jointly and severally

Article 17.3 lets you claim the whole amount from any one agent when the cause cannot be isolated.

Warranty	Covers	Who answers for it
1 year, execution defects	Finishing and finish elements: paintwork, tiling, fittings, anything cosmetic or superficial to the finished work.	The constructor alone. This is the narrowest and shortest-lived of the three.
3 years, habitability defects	Constructive elements or installations whose failure means the property no longer meets basic habitability requirements: plumbing, electrics, insulation, waterproofing.	The constructor and, in practice, whichever installer or subcontractor carried out the specific failing work.
10 years, structural defects	Foundations, supports, beams, floor slabs, load-bearing walls and other structural elements: damage that threatens the building's mechanical resistance and stability.	The full set of building agents together, the developer, the architect, the site-supervising technician and the constructor, jointly and severally where the specific cause cannot be isolated to just one of them.

Position as of August 2026, based directly on LOE article 17. Article 17.3 sets out the joint-and-several rule clearly: where the cause of the damage cannot be pinned on one party, or several agents contributed to it, the injured party can claim the whole amount from any one of them. They then settle the split among themselves.

Bank guarantees

Sources

Law 38/1999, Building Regulation, article 17, consolidated text (BOE) ↗

Do I have to work out exactly which of the four agents caused a structural defect before I can claim?No, and this is exactly what the joint-and-several rule is for. Where the cause genuinely cannot be pinned on one agent, or more than one contributed, you can direct the full claim at any one of them. This is typically the developer, since it is usually the easiest party to identify and hold to account. They then settle the split among themselves.

What happens if the builder or developer is gone by the time you need them?

Seguro Decenal is the compulsory ten-year insurance covering structural defects in a new building. Spanish construction law requires it. It sits with the building, not with you, so it carries over to the next owner. This detail matters most in practice: the cover exists because a structural defect can appear long after a small construction company has closed, merged, or simply stopped trading. A warranty that depended on that company still existing would be worthless exactly when it mattered most.A technical body called an Organismo de Control Técnico (OCT) must review the project before an insurer will issue this cover. Its involvement is a legal requirement for buildings mainly intended for housing. For a buyer, the practical point is not the OCT itself, which you will rarely deal with directly. The point is that its sign-off is what makes the insurance policy exist at all. This is why you should confirm the policy exists, not just assume it because the building was completed and sold.

Was the property principally intended for housing?
What it grantsAn Organismo de Control Técnico must review the project
If noA narrow self-build exception may apply. Confirm this with a lawyer.
Did the OCT sign off before completion?
What it grantsThe insurer can issue the compulsory decenal cover
If noNo sign-off, no cover. Worth confirming this exists before you buy.
Is the decenal policy current and does it name the building?
What it grantsA structural claim runs against the insurer, not the builder
If noWithout it, a claim has no target if the original company is gone.

The cover sits with the building, not the company, so it survives the builder closing, merging or entering insolvency.

A claim against this insurance runs against the insurer, not the original builder. This works in much the same way as a payment guarantee claim, which runs against a bank, not an insolvent developer. If the developer has separately gone through formal insolvency for unrelated reasons, this does not affect a structural warranty claim made years later against the decenal insurer. The two are entirely different obligations, owed by entirely different companies.Confirming that this policy exists and is current, before you buy rather than after a defect appears, is exactly what Arevont's technical-inspection service checks.

Glossary: Seguro Decenal

Developer insolvency

Sources

Law 38/1999, Building Regulation, article 19, consolidated text (BOE) ↗

Buying a resale property instead? What does "no warranty" leave you with?

None of this applies to a second-hand property, which carries no statutory warranty of the kind above. What it does carry is a much narrower right: a claim against the seller for a hidden defect (vicio oculto) that existed at the time of sale, which the seller knew about and hid. The site's own material has always described this deadline as "short" without naming it. It is six months from the date of delivery, and it is a strict deadline of caducidad, not the ordinary kind of prescription. Unlike most claims, it cannot be paused or restarted by a formal demand. This makes it far less forgiving than it sounds.

Delivery5 years (ordinary prescription)

Vicios ocultos claim window6 months

6 months: A strict caducidad. It cannot be paused by a formal demand

A resale property’s hidden-defect claim runs only 6 months from delivery, far short of ordinary contract deadlines.

Requirement	What it means for you	Where it comes from
The defect must be grave, hidden and pre-existing	Something serious, not visible on a reasonable inspection before you bought, and already present at the time of sale rather than caused afterwards.	Código Civil, art. 1484
You choose between two remedies	Rescind the sale entirely (acción redhibitoria), or keep the property and claim a proportional reduction in price (acción quanti minoris).	Código Civil, art. 1486
The deadline is six months from delivery	A strict cut-off, not the general five-year prescription that applies to most other contractual claims, and one that cannot be interrupted by sending a formal demand.	Código Civil, art. 1490

Position as of August 2026, based directly on the Código Civil's consolidated text. This is the deadline that the site's own service pages have called "short" without stating a number. It is stated here, sourced, for the first time.

Technical inspection

Sources

Civil Code, articles 1484, 1486 and 1490, consolidated text (BOE) ↗

What to gather the moment a defect appears

Four things, gathered quickly. Two of the three deadlines run from when the defect appears or the property is delivered, not from when you get around to acting.

Gather	Why	What a weak version looks like
A dated, written record of when you first noticed the defect	The two-year LOE claim window, and the six-month resale property deadline, both run from a specific date. An undated discovery weakens exactly the fact your claim depends on.	Relying on memory of roughly when something was first noticed.
An independent technical opinion on the cause and its likely tier	Whether a crack is cosmetic, a habitability issue, or genuinely structural decides which warranty, which deadline, and which party applies.	Assuming the category from how alarming the defect looks rather than from a professional assessment.
On a new build: confirmation the decenal insurance policy exists and is current	This is what a structural claim is made against if the original builder is no longer trading.	No record of the policy, or an assumption that "it must exist" because the building was legally completed.
On a resale property: evidence bearing on what the seller really knew	A vicios ocultos claim requires showing the seller knew about and hid the defect, not merely that it existed.	A claim resting only on "they must have known", with no supporting evidence at all.

What does a lawyer check

A new-build structural warranty against a resale property hidden-defects claim

Both eventually pay out for a real, serious problem, but the process to get there is completely different.

	Second-hand property (hidden defects)	New build (LOE guarantee)
Legal basis	Código Civil, arts. 1484-1490.	Ley 38/1999 (LOE), arts. 17-19.
Deadline	Six months from delivery, a strict caducidad that cannot be interrupted.	Up to ten years, with a two-year window to claim once the specific damage appears.
What you must prove	That the defect existed at the sale, was serious and hidden, and that the seller knew about it and hid it.	That the damage falls into one of the three defined categories, within its own time limit.
Who you can claim against if the original party is gone	Generally nobody. This is a personal claim against the seller specifically.	The compulsory decenal insurer, for the structural tier, regardless of whether the builder is still trading.

Frankly

This states the legal framework, not a verdict on your specific defect

This is current Spanish law as of August 2026, based directly on the LOE and the Código Civil, not assumed from how these warranties are usually summarised. It is general information, not an assessment of any specific defect. Whether a particular crack, leak, or fault falls into one warranty tier rather than another, and whether a seller genuinely knew about and hid something on a resale property, are technical and factual questions. An independent expert and lawyer answer these for your specific property. Nobody can determine this in the abstract.We do not issue the decenal insurance, and we are not a party to your warranty or your claim. What our snagging and technical-inspection services do is find and document defects at the moments that matter most: before you sign on a new build, and before you buy a resale property. At that point, most of what is described above is far cheaper to deal with than it is afterwards.

Most common questions about construction defects

Do I need a lawyer to make a claim against the decenal insurance, or can I contact the insurer myself?: You can contact the insurer directly, but a lawyer or an independent technical expert makes a claim like this much stronger, because the insurer wants a clear technical basis for classifying the damage as structural rather than a lesser category. For anything beyond a minor, obvious case, the cost of that expert opinion is usually small compared to what a structural claim is worth.
If I bought a new build and the ten-year structural warranty has not yet expired, does it matter that I am not the original buyer?: No. The seguro decenal attaches to the building itself, not to the person who first bought it. So a later owner who buys within the original ten-year period inherits the same cover for whatever time remains. This is worth confirming specifically when buying a fairly new resale property still inside its original ten-year window, since it is a real, transferable asset of the property.
On a resale property, is a defect the previous owner simply did not know about treated the same as one they hid on purpose?: No, and this is the central difficulty of a vicios ocultos claim. The seller only answers for a defect they really knew about and hid, not for one that existed without their knowledge. This is a real, meaningful right, but proving what someone else knew is a much harder task than pointing to a statutory warranty period. This is exactly why the pre-purchase inspection matters more on a resale property than on a new build.

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