Built area and usable area

Built area: what is inside the figure

Built area, superficie construida in Spain, is measured to the outer face of the external walls. Everything within that outline counts: the rooms, the partitions, the thickness of the walls, the columns and the ducts. It is the figure that normally appears in a price list and in the deed of division of the building.

It comes in two versions, and a listing seldom says which one it means. Built area without common parts covers the dwelling alone. Built area with common parts adds the share of the entrance hall, the stairs, the lift shaft, the corridors and the plant rooms that belongs to the unit. The second is larger, and in a building with generous common space the gap is not small.

The area recorded for the flat in the land registry, and visible in the nota simple, is normally a built figure. That is one reason a tape measure never agrees with the deed.

Usable area: the floor you walk on

Usable area, superficie útil, is measured inside the enclosing walls to their inner face. Partitions, wall thickness and shafts drop out of it. Conventions differ on the edges: whether a built-in wardrobe counts, and how much of a room under a sloping ceiling counts, is handled differently from one surveyor to the next, so ask how the figure in front of you was produced.

The two measures answer separate questions. Usable area tells you what the dwelling will hold, which is the question you ask with a sofa and a dining table in mind. Built area tells you what you are buying and what the deed will say. Neither is the honest one; they are simply different.

The ratio between them is informative in itself. A compact plan with few partitions loses little from built to usable. A plan with thick structural walls, a long internal corridor and several risers loses considerably more. Compare the ratio across two flats of the same built area and you see which layout is more efficient.

Terraces, balconies and storage

Open and semi-open space is normally counted at a fraction of its measured area when it is added into the figure for the dwelling, on the reasoning that a terrace is not worth the same per square metre as a living room. The fraction applied depends on local rules and on how enclosed the space is, so it varies from one project and one region to another. Roughly, in order of how much is counted:

• an open balcony, the smallest fraction, or shown on its own line and not added at all;
• a terrace covered by the floor or the roof above, a larger fraction;
• a glazed gallery closed on all sides, often counted in full;
• a roof terrace reached only from the dwelling, usually a separate line, and sometimes a common element over which the flat holds exclusive use rather than ownership;
• a parking space and a storeroom, separate units with their own areas and frequently their own registry entry, outside the figure for the flat.

So do not ask for the total alone. Ask for the measured area of each outdoor space and the fraction applied, and the total becomes checkable.

The distinction has consequences past the price list. Where a roof terrace is a common element with exclusive use, it cannot be altered at will, and a change to it can need a decision of the community of owners. Your notary will tell you which of the two you are being sold.

Common parts and the participation quota

Everything that is not inside a unit is common: the structure, roof, facade, entrances, lifts, corridors, pool, grounds and plant rooms. Each unit holds an undivided share of all of it, and that share is the participation quota written into the deed of division.

The quota does two jobs at once. It allocates the common costs between the units, and it is the basis on which the share of common parts is added to a built area. So the same document that fixes what you pay each month also fixes the larger of the two square-metre figures quoted to you.

Why one apartment shows two figures

Two listings for one flat can disagree without either being dishonest. One may quote built area with common parts and the other built area without them. One may fold the terrace in at a fraction and the other leave it out. One may be working from the architect's drawing and the other from the survey of the finished building. Rounding then adds a square metre here or there.

From the plan means the figure is taken from the design before the building exists. After completion, the as-built survey and the declaration of new work fix the final areas, and they can move slightly against the design. A contract for an unbuilt flat should say which figure binds the parties and what happens if the delivered area falls outside the tolerance it allows; read that clause before the reservation, not after.

SAVO states built area and usable area separately for its own apartments and puts terrace area on its own line, so the figures can be set against another developer without recalculation. When you compare two offers, establish which definition each seller used before you conclude that one flat is bigger than the other.