Buying a Villa in Marbella: How an Illegal Extension Was Detected Before Completion
Case study shared by PL Lawyers Málaga Marbella Associates, a member firm of Property-Lawyers.com.
Short answer: many villas on the Costa del Sol have extensions, terraces, pools or basements that were built without a licence or never declared. If you buy such a property, you can inherit the problem: limits on resale, mortgage and insurance issues and, in some cases, sanctions. A property lawyer’s due diligence should compare what exists on site with what is recorded in the Land Registry, the Cadastre and the town hall before you commit any money.
The case: a luxury villa marketed as fully compliant
A Scandinavian client was in the process of buying a luxury villa in Marbella. The property appeared to be in excellent condition and the listing described it as fully legal.
During legal due diligence, the firm found that a significant extension, including part of the living area and a terrace, had not been properly registered or declared to the authorities. The built area on the ground did not match the official records.
The firm advised the client to pause the transaction and renegotiate. In the end, the client withdrew, avoided a high-risk purchase with an uncertain legal status, and later bought a different property with the same firm’s help.
How the extension was detected
Unregistered works are rarely visible from the listing. They show up when the documents are compared with each other and with the property itself:
- Land Registry (nota simple): shows the registered description and built area of the house.
- Cadastre: shows the area recorded for tax purposes, which may differ from the Registry.
- Town hall records: building licences, first-occupation licence and any planning infringement files.
- Plans and a site visit: an architect or surveyor confirms what has actually been built.
When the real built area is larger than what appears in these records, the difference needs an explanation and supporting documents before you sign.
Why an unregistered extension is a problem
| Risk | What it means for the buyer |
|---|---|
| Planning sanctions | If the works were built without a licence and the authority can still act, it may impose fines or order the restoration of legality. |
| Resale | A future buyer’s lawyer will find the same discrepancy, which can delay a sale or reduce the price. |
| Financing | Banks and valuers usually rely on the legally recorded area, so the mortgage may be based on a smaller property. |
| Insurance and utilities | Insurers and some procedures depend on accurate records; undeclared areas can cause disputes. |
| Rental licences | A holiday-rental registration may require the property to be in order. |
Can an illegal extension be legalised?
Sometimes. Depending on the land classification, when the works were finished and whether the authority’s time limit to act has expired, it may be possible to regularise them through a licence or, for older works on which the council can no longer act, through recognition of the asimilado a fuera de ordenación status in Andalusia. That status allows the building to be used and registered but does not make it fully compliant, and stricter rules apply on protected rustic land.
Legalisation needs a technical report, fees and time. Whether it is possible must be checked case by case by a lawyer and an architect; never assume it from the agent’s description.
Your options if your lawyer finds a problem
- Ask the seller to regularise before completion, with the deed postponed until the documents are issued.
- Renegotiate the price to reflect the cost, time and risk of regularisation.
- Retain part of the price at completion until the regularisation is obtained, if the seller agrees and the contract says so clearly.
- Walk away, ideally before paying a deposit, or under a contract condition that allows you to withdraw if the due diligence reveals irregularities.
Key lesson: instruct your lawyer before signing a reservation or arras contract. Once a deposit is paid, withdrawing because of a problem you could have found earlier may cost you that deposit.
Frequently asked questions
Is it common to find illegal extensions in Marbella?
Discrepancies between the built area and the official records are a frequent finding in villas on the Costa del Sol, particularly in older homes and properties on rustic land.
Who is responsible for an illegal extension after I buy?
Planning problems are attached to the property, so a buyer can be affected by works carried out by a previous owner. That is why the checks must be done before completion.
Does the notary check whether the property is legal?
The notary checks identity, title and certain formalities, but does not carry out a full planning investigation. That is the job of your own lawyer and technical adviser.
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Case details have been summarised to protect client confidentiality. General information, not legal advice for your specific transaction.
Sophie Gutenberg is a legal content specialist focused on Spanish property law, real estate transactions, conveyancing, due diligence and tax issues affecting international property buyers in Spain. She works alongside qualified Spanish property lawyers .
