In Barcelona, the same apartment can be described using several different surface areas. The listing, the Cadastre, the cédula de habitabilidad and the nota simple do not always show the same figure.
That does not necessarily mean that one of the documents is wrong. But before buying, you need to understand what each figure measures — and check that they remain coherent.
Built area: the figure used in listings
Estate agencies most often advertise the built area. It includes the useful internal area, as well as the space occupied by walls and partitions. Depending on the calculation method, covered balconies and terraces may be counted at 50%.
The useful area is closer to the floor space you can actually live in and furnish. In practice, it is often around 10% lower than the built area. An apartment advertised as 100 m² built may therefore offer roughly 90 m² useful — but the agency should confirm this rather than leave you to assume it.
Cadastre, cédula and nota simple: figures to cross-check
The Cadastre states a built area that may also include a share of the building’s common areas. The cédula records the useful area used for habitability purposes. The nota simple, an essential Land Registry document when checking a property, contains its registered description: you need to see whether the stated surface is useful or built, then compare it with the other documents.
When the difference distorts the price per square metre
Take an apartment priced at €500,000 and advertised as 100 m² built:
We sometimes see the useful area increased by 15, 20 or even 30% to produce the built figure shown in a listing. Without a clear explanation — walls, terrace, common areas or an old registered description — the investment calculation is distorted.
When the gap between the advertised built area and the useful area exceeds 10 to 15%, we ask why. If the documents do not align, a survey by a technician brings the calculation back to the physical reality of the property. Even for a main residence, surface area matters: you are also buying an asset at a price per square metre.