Buying a Spanish home with an unregistered extension: checks before a deposit

Pause before paying for a Spanish home when an extension, enclosed terrace, converted garage, extra floor, pool or annex is missing from one or more records. First identify and measure the physical addition. Then compare the title and Land Registry information, Catastro description and the municipality's authorised plans, licence and occupation file. Establish why they differ and make the transaction depend on a defined result where the answer matters. A discrepancy is not proof of illegality, while matching areas do not prove that every approval exists.

Place this check inside the wider Spanish buying process.

Translate the records before comparing their numbers

An escritura is a notarised deed; it records the legal act and includes a property description. A nota simple is an informative extract from the Registro de la Propiedad, Spain's Land Registry, showing the registered property, rights and entries at the time it is issued. Start with the nota simple reading guide, but do not expect the extract to certify the planning history of every wall.

Catastro is the administrative real-estate cadastre. Articles 2 and 3 of the consolidated Cadastre Law set out the role and content of cadastral information without displacing the legal effects of the Land Registry. A cadastral outline, tax bill or recorded floor area can be useful descriptive evidence; it is not a municipal works permit.

A licencia de obra is a municipal works licence. A declaración de obra nueva is the formal declaration used to document a new building or alteration for notarial and registry purposes; it is not simply another name for planning permission. Occupation or habitability documents have their own scope and territorial rules. Keep these labels attached to the question each document can answer.

Create a discrepancy schedule that follows the building

Walk through the property with a plan and list each possible difference separately. Record the element, measured area or use, where it appears in the physical building, and whether it can be found in the deed, registry description, cadastral plan and municipal drawings. Note uncertainty instead of rounding several rooms into one unexplained total.

Photographs and a measured sketch make the file reviewable, but do not establish authorisation. Commission the pre-purchase building inspection with a written scope. A sound extension can have an unresolved file; a documented one can be defective.

If the identifiers, boundaries or plans will not align, work through the Registry, Cadastre and boundary evidence guide. Ask a suitable professional to map the registered property, cadastral parcel and actual structure rather than treating a portal plan as their common denominator.

Ask the municipality about the particular addition

Request the file for the exact address and building. Depending on the case, relevant material may include the approved project, works licence, approved amendments, submitted declarations, completion evidence, inspection records and applicable first-occupation or use documentation. In its off-plan section, Spain's central-government page on property transactions, notaries and registers lists licence, technical conformity, occupation and registration evidence separately. That warns against asking one record to do every job.

Frame questions around the discrepancy: is the terrace shown in the authorised project; was the garage conversion covered; do the pool's location and dimensions correspond; is there an enforcement file; and what planning or heritage constraints apply? Record the source, date, supporting document and any qualification.

Municipal practice and regional law differ. The documentation appropriate to a flat in one autonomous community may not match that for a rural house elsewhere. The guides to the first-occupation licence and habitation certificates explain common distinctions, but neither should be turned into a Spain-wide municipal checklist without checking the location.

Do not turn an older-work registration route into planning approval

Articles 27 and 28 of Spain's consolidated Land and Urban Rehabilitation Law do different jobs: transferring the property does not erase the owner's planning duties, while recording new construction requires the applicable evidence. Article 28.4 provides a registry route for certain works where restoration measures involving demolition can no longer be taken because the relevant limitation periods have expired. It has conditions; it is not a nationwide fixed period, automatic legalisation or a guarantee of future alteration, occupation, services, valuation or lending.

Fuera de ordenación broadly refers to a planning status for a building that does not conform to current planning, but the exact status, terminology and consequences come from autonomous-community legislation and municipal planning. It may limit which works are allowed. Do not apply the term merely because two area figures differ, and do not assume age removes all restrictions.

The Cadastre's official procedures page lists new construction, extensions, rehabilitation and changes of use among cadastral alterations handled through its procedures or communications. Updating that administrative description is not retrospective planning consent. Likewise, paid property tax, connected utilities, an old aerial photograph, an estate agent's statement or a bank valuation does not close the municipal question.

Test the gap against the reason you are buying

Write down the use that gives the addition value. Perhaps the annex must be lawful accommodation, the former garage must function as a bedroom, or the enclosed terrace is needed to make the kitchen plan work. Ask whether the evidence supports that exact use and whether the renovation you intend would be permitted. Being able to stand in a room today is not evidence that you can alter it tomorrow.

Carry the answer into the renovation-property assessment. Separate work required by physical condition from work that depends on permissions or documentary completion. A quotation for finishes cannot price an unknown planning route, so do not fill the gap with an invented allowance or completion date.

Finance needs its own conversation. A Spanish mortgage valuation may disregard floor area, state assumptions or request documents, but its purpose is not to issue municipal approval. Ask the lender how an unresolved addition affects its process while keeping the planning conclusion with the competent records and advisers.

Use a fictional pair to expose different kinds of uncertainty

Consider two entirely fictional purchases. Olive House has an added utility room absent from its current registry description. The buyer's schedule connects the room to an approved municipal drawing and completion evidence; a professional still needs to determine the correct declaración de obra nueva and registry steps. Cedar House has an enclosed upper terrace shown by Catastro, while the seller supplies no authorised drawing, licence or municipal response and points only to its apparent age.

The evidence does not justify calling Olive House “legal” and Cedar House “illegal”. Olive House presents a potentially documentary gap with specific checks still open. Cedar House lacks the material needed to classify the addition and predict whether the buyer's intended use or works can proceed. The second buyer should not pay for a hoped-for regularisation as though it were completed.

Compare evidence available, question outstanding and consequence for your plan. A smaller documented home may serve the project better than a larger one whose essential room remains uncertain. A traceable discrepancy should be investigated, not rejected by slogan.

Convert due diligence into a contract gate

An arras agreement is a Spanish private deposit agreement whose effect depends on its wording and legal type; a reservation payment also has no universal automatic cancellation rule. Before either payment, choose one of three responses:

• Proceed when the physical work is identified, the evidence explains the mismatch and the essential use has a reliable basis.
• Make the purchase conditional when a defined document, conclusion or seller action must be delivered before you become bound.
• Stop when the extension cannot be identified, the required use depends on uncertain regularisation, or adequate file access is refused.

Use the reservation and arras guide to test the actual draft. A useful condition names the evidence or outcome, deadline, responsible party and consequence of failure. A list headed “to be checked” is not itself a contractual exit.

To define the next review, tell CASA i CASA the municipality, buying stage, physical addition, records that disagree and documents already supplied. Include the use or renovation that must remain possible, but avoid sensitive identity documents in the first message. This creates a practical scope without promising registration, planning consent, finance or regularisation.