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Building or extending in Torrevieja and Orihuela Costa: costs and permits
Enclosing the porch, adding a floor, building from the foundations up: each of these jobs has its own cost per square metre and its own council paperwork — and mixing them up gets expensive. This guide puts all three in order, with the real 2026 ranges and the permit that applies to each case.
Costs per square metre in 2026
| Type of work | Estimated range |
|---|---|
| Porch or solarium enclosure | €500–900/m² |
| Extension with new foundations | €900–1,400/m² |
| Complete new build, detached home | €1,100–1,600/m² |
The logic of the scale is simple: an enclosure uses existing structure; an extension adds new foundations and roof; a new build constructs everything from the cleared plot up. Every job in this table runs with a technical project and site management — the detail is on the new builds and extensions page.
Which permit each job needs (and where it's processed)
The rule that sorts everything: if the work increases built volume or floor area, it needs a licencia urbanística (full building permit) with a technical project. That covers enclosing a porch or terrace into the home, any extension and, of course, a new build. Only when an enclosure adds no volume can a declaración responsable (the simplified notification-based permit) be enough — and that gets checked case by case before starting, not after. The full rundown of both permit types is in the permits and paperwork guide.
Where you file depends on the municipality: for the Orihuela Costa urbanisations, at Orihuela's municipal office on the N-332 in Playa Flamenca — no 35 km trip to Orihuela town; for Torrevieja and its urbanisations, at the town hall itself. We prepare and file the paperwork as part of the project, with enough margin so the permit never threatens the agreed start date.
The three cases we see most in the area
Enclosing the porch of a 1980s-90s townhouse or bungalow. It's the classic extension in urbanisations like Playa Flamenca, Los Balcones or Villamartín: turning the porch into a glazed room or the solarium into a bedroom. The key is in the paragraph above — if it adds volume, it's a full permit with a technical project.
Buying a home with old unpermitted extensions. Very common in coastal purchases: a previous owner enclosed without paperwork. Orihuela regularises it through the Declaración Responsable de Segunda Ocupación (Second Occupation declaration), and it's worth resolving before renovating on top of anything unregularised.
Building on your own plot. In areas with sloped plots, such as Cabo Roig, the project has to resolve retaining walls and access as well as the house itself: line items you want reflected in the quote from day one, not as a mid-build surprise. If you already work with an architect or interior designer, we execute their project and coordinate with them throughout.
FAQ
The questions we hear most about building and extending
Can I enclose my porch with just a declaración responsable?
It depends on whether the enclosure increases built volume or floor area: if it does — the usual case when incorporating the porch into the home — you need a licencia urbanística (full building permit) with a technical project; if not, the declaración responsable may be enough. We check it case by case before starting.
How much does an extension cost per square metre?
An extension with new foundations runs between €900 and €1,400/m² in 2026. A porch or solarium enclosure, which uses the existing structure, between €500 and €900/m². These are estimated ranges: the fixed quote comes from the technical visit and the project.
And building a house from scratch?
A complete new-build detached home sits between €1,100 and €1,600/m² in 2026, executed with a technical project, council permit and site management.
I've bought a house with an unpermitted extension — what do I do?
It's a frequent situation on the coast. In the municipality of Orihuela it's regularised through the Declaración Responsable de Segunda Ocupación (Second Occupation declaration); it's worth resolving before undertaking new work on top of anything unregularised. We handle it as part of the project.
How long does the building permit take?
It varies by municipality and by each technical office's workload; that's why we file the paperwork with enough margin so the permit never threatens the start date agreed in the work schedule.
Can you work with my architect?
Yes, it's common: we execute your architect's technical project or coordinate directly with your interior designer throughout the build, with a single point of contact on our side.
Estimated 2026 prices, not binding. The final price comes from the free technical site visit and depends on quality specification, access to the property and starting condition.