How to check the real floor area of a property in Spain (listing vs Cadastre)

You pay per square metre, but the figure in the listing is written by the seller or the agency, and it doesn't always mean what you think. Before making an offer it's worth knowing how many square metres the property really has and what kind they are. The good news: the official floor area can be checked for free in the Spanish Cadastre with the address or the cadastral reference. This guide explains how, how to read it, and what to do if it doesn't match the listing.

The three kinds of «square metres» in Spain

• Usable area (superficie útil): the floor you can walk on inside the home, measured inside the walls. The smallest of the three.
• Built area (superficie construida): usable area plus partitions, walls and the home's share of the façade. Usually 15–25 % larger than the usable area.
• Built area including common areas: built area plus a proportional share of the entrance hall, stairs, landings and other shared parts. The largest figure, and the one most listings use.

None of them is «wrong»: the problem is comparing figures of different kinds. A flat with 90 m² built including common areas may have around 70 m² of usable space. If you work out the price per metre with the big figure and compare it with another listing that quotes usable area, the comparison doesn't hold.

How to check the official area in the Cadastre

• With the address or cadastral reference, on the Cadastre's online office (Sede Electrónica del Catastro), a free search of non-protected data with no digital certificate needed.
• What you'll see: the property's use, year of construction and the built area of each home, commercial unit, storage room or parking space. For flats, the area shown already includes the share of common areas.
• In a building with several homes, find yours by staircase, floor and door: each one has its own 20-character cadastral reference.

Hogarfax does this comparison for you: when you analyse a property it shows the official area and, if you come from an Idealista listing through our extension, it puts it next to the advertised square metres so you see the difference at a glance.

What it means when the figures don't match

• The listing shows slightly more than the Cadastre: usually the listing uses the area with common parts, or rounds up. Ask the seller for the usable area and where the figure comes from.
• The listing shows a lot more: there may be an extension, an enclosed terrace or an attic that was never declared. It isn't only about metres: what wasn't declared may not be legal either.
• The Cadastre shows more than the listing: this happens when the listing gives usable area, or when part of the area is a storage room or parking space on the same record.
• The Land Registry extract shows yet another figure: the registered area may differ from the Cadastre's, especially for older properties. Since 2015 the law aims to coordinate both, but many properties are still not coordinated.

What to do before making an offer

• Work out the price per metre with the Cadastre's built area, and compare it with other homes always using the same kind of metres.
• Ask for the usable area in writing (it usually appears in the energy performance certificate or the valuation).
• If the gap is large, ask about works and permits and check the Land Registry extract (nota simple).
• If you need a mortgage, the bank valuation will measure the property: if its figure is below the listing's, the bank lends on its figure, not the listing's.

No online check replaces measuring the property when you visit, but five minutes with the Cadastre saves you from negotiating on a figure that isn't what it seems.