Spanish apartment floor area: usable space, built area and terraces on the Costa del Sol

The square metres in a Spanish apartment advertisement are not necessarily the size of its furnishable interior. For a new-build apartment on the Costa del Sol, ask separately for internal usable area, the built-area calculation, the terrace, and garage or storage details. You can meaningfully compare two homes only when the figures measure the same thing.

A large terrace can be a valuable part of a Mediterranean home, but it serves a different need from a spacious living room or study. One combined sqm figure does not tell you whether your family will fit, where storage will go or how much space remains around furniture. The method below helps turn an advertised number into useful buying information.

Which area are we talking about?

Article 2 of Andalusia's Decree 218/2005 defines usable area by the internal boundary, excluding, for example, the space occupied by internal walls and vertical structural elements. Built area also includes walls and, where applicable, the proportional share of common building areas. Source: BOJA, official consolidated text of the decree.

Always read the short label in an advertisement or floor plan alongside its calculation notes. “Total” alone does not explain what has been added together. Do not automatically convert built area to usable area using a percentage found online: obtain the schedule for the actual apartment.

On your comparison sheet, keep separate lines for internal space, terrace, storage room and parking space. If a figure is unknown, leave it blank and mark it as a question. Do not replace a missing internal measurement with the largest number in the advertisement.

A terrace is not always simply added to the square metres

The Andalusian consumer-information definition above includes half the area of private-use external spaces in usable area, capped at 10% of enclosed usable area. This is the calculation in that regional rule; it cannot automatically be transferred to a schedule prepared for another purpose. Source: Decree 218/2005, Article 2(e).

Illustrative example: assume enclosed usable area, measured under the rule, is 80 sqm and a private-use terrace is 24 sqm. Half the terrace is 12 sqm, but the cap is 80 × 10% = 8 sqm. In this example, usable area under the decree is 80 + 8 = 88 sqm. The actual terrace remains 24 sqm and the internal space remains 80 sqm.

The example uses invented dimensions to explain the calculation; it does not describe an apartment for sale. “80 sqm internal space + 24 sqm terrace” therefore answers a different question from the 88 sqm calculated under the rule. Before reserving, request a breakdown clearly identifying what each figure represents.

Which floor plan and documents should you request?

In Andalusia, a planned or under-construction home offered through a business or professional activity is covered by the Documento Informativo Abreviado, or DIA. Consumo Responde says it must be supplied free to a consumer requesting information; it includes usable areas of the home and its annexes, and a dimensioned furnishing floor plan at a scale of at least 1:100. Source: Consumo Responde, home-purchase documents.

We explain the terrace rule above in the Costa del Sol's Andalusian consumer-information context, checked on 8 October 2026. Do not assume the same detailed rule applies in another Spanish region.

Match the development, building, floor and apartment identifiers across the documents received. A neighbouring apartment, mirrored version or show-home plan may not represent the selected property's layout. Check the plan's date and revision too, and request the latest version relating to the offer.

Our Spanish property buying guide outlines the other purchase steps. Check dimensions during selection: a favourable payment schedule cannot later substitute for a suitable layout.

Five practical floor-plan tests

1. Draw in your own furniture

Record the dimensions of your bed, sofa, dining table and required storage. Test rooms using these rather than relying only on furniture icons in the illustration. Check that comfortable routes remain in front of doors, wardrobes and the terrace exit. A home with a larger overall area can still be less suitable if the important rooms' proportions do not match your needs.

2. Examine circulation space

Mark how you would walk from the entrance to the kitchen, bedroom and terrace. A corridor is necessary space, but it does not provide the same use as a furnishable living room. Decide how much circulation space suits your own needs.

3. Look at the terrace's shape

Of two equally sized terraces, one may be easy to furnish while the other is narrow or fragmented. Ask about usable width, columns, equipment and the exit's position. Consider the space needed for dining, relaxing and drying laundry; shape as well as area determines how you can use it.

4. Check storage and parking

The bedroom count does not reveal whether luggage, sports equipment or cleaning supplies will fit. For a separate storage room, inspect access too. For parking, width, columns and manoeuvring space may matter more than overall area. Compare the plan's dimensions with your own car's space requirements.

5. Start with everyday use

A few weeks' holiday, several months' residence and working from home may call for different layouts. Write down your three most important functions: for example, a separate workspace, two genuinely usable bedrooms and a spacious dining area. Test every candidate against these before ranking it by views or the shared pool.

Price per square metre: clarify the denominator first

When comparing prices, use the same area definition and the same package included in the price. Invented numerical example: dividing a €400,000 offer by 100 sqm of built area gives €4,000/sqm. If separately verified internal usable space is 80 sqm, the same price divided by that area is €5,000/sqm. Here, the difference results from the calculation, not a price increase.

These are neither market averages nor actual offers, and neither division is a property valuation. Clarify separately whether parking, storage and taxes are included. If they are included for one apartment but charged separately for another, first establish comparable amounts. Read our property price overview with the same question in mind: which area and which costs sit behind the figure?

What if two documents differ?

Keep the offer, advertisement and dated floor plan. Under Article 3 of Spain's Royal Decree 515/1989, property characteristics in an offer or advertisement can be enforceable even if the contract does not expressly list them. This does not mean every discrepancy automatically produces a refund. Source: BOE, home-purchase consumer information.

First request a written explanation: are they comparing the same apartment, plan revision and measurement method? If the difference remains unexplained, have the technical calculation checked by an appropriate professional and the contractual consequences by an independent Spanish lawyer. Do not close an unexplained discrepancy using a general percentage said to be acceptable.

For a completed home, comparing the plans with the actual condition can also form part of handover. Our new-build property handover checklist provides further points to consider.

What should you bring to the final comparison?

Separate internal area, separate terrace, identified parking and storage, a dated plan and a clear price. If these all relate to the same apartment, and your furniture, daily routes and intended uses fit the plan, you can decide using far more than a single large sqm figure.

If you are looking for a new-build apartment on the Costa del Sol, tell us your internal-space, terrace and storage needs during a SpainProperty consultation. The comparison can then consider how you want to use the home as well as your budget.