The 7 costliest pitfalls when buying a house in Spain

1. The unregistered extension

The coastal classic: a garage turned into a living room, a covered terrace, an extra floor — built without a permit and never registered. You buy it "as part of the house", but legally it does not exist. The consequences: problems on resale, with insurance and with mortgages, and in the worst case a legalisation process or a demolition order at your expense.
How to spot it: compare the nota simple with the Catastro and with what you can see. Discrepancies mean it is time to ask questions.

2. Community and tax debts that come with the house

Outstanding comunidad fees (current year plus three years back) and unpaid IBI can be recovered against the property — which means against you.
How to spot it: a debt clearance certificate from the community administrator and an IBI statement from the town hall or SUMA, both before the notary.

3. Embargos and hidden mortgages

Seizures by the tax authorities or by creditors are recorded in the registry in plain sight — but you do have to look.
How to spot it: a fresh nota simple at the arras stage and again just before the notary; and make redemption of any mortgage a contractual condition of completion.

4. No habitation certificate

Without a valid licencia de ocupación / cédula de habitabilidad you can run into trouble in the Comunidad Valenciana with utility connections and with tourist rental.
How to spot it: request it from the town hall; on older properties, check whether it needs to be extended or renewed.

5. Coastal and planning rules

The Ley de Costas and local zoning plans can restrict building, renovating or even retaining a property — particularly close to the sea or on rústico (rural) land.
How to spot it: a planning report (informe urbanístico) from the town hall. A standard part of proper due diligence.

6. The inflated asking price

There is no transparent national sold-price history on the coast the way there is in northern Europe; asking prices are sometimes set 15–25% above real value simply "because it works" on foreign buyers.
How to spot it: compare per m² against recently sold properties (not: currently listed ones), and factor the full costs into your offer.

7. Signing too early

The most expensive mistake is not a document but an order of events: reserving and paying a deposit first, and only then having the checks carried out. The arras contract is binding — 10% gone if you withdraw.
How to avoid it: sign nothing until the checks are complete, or include an explicit condition allowing you to withdraw based on the outcome of the due diligence. See the buying process step by step.