Legal & permits
Do You Need an Architect to Renovate a House in Spain?
Whether you need an architect depends on what the works change, not on how much they cost. Here is how the rules usually work, and when professional design pays for itself anyway.
· 7 min read · CostaVeyra Renovations
You need an architect in Spain when your renovation changes the structure, the volume, the exterior composition or the use of the building. In those cases Spanish law requires a technical project, and the town hall will normally ask for one before granting a licence. For a new kitchen, new bathrooms or new floors with no structural changes, an architect is usually not legally required, although there are good reasons to involve one on larger projects.
What follows is general guidance. Procedures are set by each ayuntamiento, so always confirm the specifics for your property with the town hall or a local architect.
What the law actually says
Spain’s Building Act, the Ley de Ordenación de la Edificación (LOE, Ley 38/1999), requires a technical project for works on existing buildings that alter the architectural configuration. In practice, that means works that:
- change the exterior composition, such as new or enlarged openings, a remodelled façade or a new roof shape;
- change the volume, such as an extension, an enclosed terrace or an extra storey;
- change the structural system, such as removing load-bearing walls, cutting new openings in slabs or replacing beams;
- change the use of the building or part of it, for example turning a garage or a riu-rau into living space.
If your plans fall into one of these categories, expect to need a project signed by a competent technician, and in most cases a licencia de obra mayor.
Declaración responsable or licencia de obra mayor
Most Costa Blanca town halls handle renovation through one of two routes. In the Valencian Community they apply regional planning law (the TRLOTUP) plus their own Plan General, so the details can vary from one town to the next.
| Route | Typical works | What you usually submit | Typical timing |
|---|---|---|---|
| Declaración responsable or comunicación previa | Non-structural interior work, kitchens and bathrooms without structural changes, flooring, painting | A form, a description and a budget; sometimes a technical report | Work can often start within weeks |
| Licencia de obra mayor | Structural changes, extensions, façade or volume changes, change of use, new pools in many municipalities | A full technical project by a competent technician | Commonly several months, often 2–6+ |
Two neighbouring towns can treat the same works differently. A new window opening might be routine paperwork in one municipality and a major-works licence in another. If the property is near the sea, the Ley de Costas may also restrict what you can do, which is worth checking before you design an extension.
Arquitecto or arquitecto técnico
Spain has two distinct building professions, and the difference matters.
The arquitecto
An arquitecto (architect) designs the project and is the usual author of projects that alter structure, volume or the exterior. On a major renovation they normally act as director de obra, responsible for ensuring the works follow the project.
The arquitecto técnico or aparejador
An arquitecto técnico, traditionally called an aparejador, is a building engineer specialising in construction. They typically handle the dirección de ejecución: checking quality, materials, measurements and execution on site. They can also sign certain non-structural projects and technical reports, which makes them a sensible choice for some interior renovations where a full architectural project is not required.
On a major villa renovation you will usually have both: the architect as project author and director, and the aparejador overseeing execution.
Health and safety coordination
Under Real Decreto 1627/1997, a health and safety coordinator is required when more than one contractor, or a contractor plus self-employed tradespeople, work on site. That covers most real renovations, since electricians, plumbers and carpenters are often separate firms. The role is often taken by the aparejador. A health and safety study or basic study is also part of the project documentation for major works.
Interior designers and architects
Interior designers play a valuable role, particularly on the layout, lighting, materials, joinery and furniture that make a house pleasant to live in. They cannot, however, sign a project for works that need one under the LOE. If your interior design involves removing walls or changing openings, the designer will need to work alongside an architect or aparejador who takes legal responsibility for those parts.
On many Costa Blanca projects the two work well together: the architect handles the structure, envelope and permits, and the interior designer develops the spaces and specification. Our page on interior design services explains how that collaboration usually works.
What an architect’s project includes
A full technical project for a major renovation usually moves through stages:
- Survey and measured drawings of the existing building.
- Basic project (proyecto básico), which defines the design and is often enough to apply for the licence.
- Execution project (proyecto de ejecución), with construction details, structure, installations, specifications and a bill of quantities by chapters.
- Health and safety documentation and a waste-management study.
- Site direction during the works, with visits, instructions and certification.
- Final certificate (certificado final de obra), which you will need for registrations, utilities and eventually a sale.
The execution project is also what allows contractors to quote like for like. Without it, quotes tend to be vague, and comparing them becomes guesswork. Our guide to choosing a renovation company on the Costa Blanca covers this in more detail.
How fees are usually agreed
Architects’ fees in Spain are not fixed by any official scale. They are agreed freely between you and the professional, and the structure varies:
- a percentage of the execution budget, which is common on larger projects;
- a fixed fee per stage, such as basic project, execution project and site direction;
- an hourly or lump-sum fee for smaller tasks such as a survey, a feasibility study or a technical report.
Whatever the structure, ask for a written fee proposal that lists exactly which stages are included, how many site visits are expected, whether the aparejador and health and safety coordination are included or separate, and how changes to scope are charged. Technical fees sit on top of the build cost, the municipal ICIO tax (up to a maximum of 4% of the execution budget, set by each town) and the licence fee. For a wider view of these costs, see how much it costs to renovate a villa in Spain.
When an architect is worth it anyway
Even when the law does not require one, an architect or experienced designer often earns their fee on a substantial project. Situations where it usually pays to involve one:
- You are reconfiguring the layout, even with non-structural walls. Good planning of light, circulation and views is where most of a home’s quality is decided.
- The budget is significant. On a full renovation, a clear specification and bill of quantities protects you from vague quotes and costly variations.
- You live abroad. Someone qualified who visits site, checks quality and answers contractors’ questions is valuable when you cannot be there, and a managed renovation, with one point of contact coordinating the architect and the works, saves you from linking the pieces together yourself. Our guide to renovating a property in Spain from abroad explores this.
- The house is older or on a slope. Many 1970s–2000s villas in Jávea, Moraira or Benissa have retaining walls, damp issues or undocumented alterations that need a trained eye.
- You may sell later. Properly documented works, a final certificate and registered changes make a future sale far easier.
- You are unsure what is permitted. An early consultation with a local architect can tell you what the town hall is likely to accept before you spend money on design.
For a small refresh, by contrast, a capable builder with a clear written quote is often enough.
How to find the right professional
Look for an architect who works regularly with the ayuntamiento where your property sits, who can show comparable renovations, and who communicates comfortably in your language. Ask who will actually visit site and how often.
How CostaVeyra works with architects
CostaVeyra manages complete renovations on the Costa Blanca, from concept to completion. We are not the architect of record: where a technical project is needed, it is signed by a qualified architect or arquitecto técnico. What we take care of is everything around it: defining the brief and budget, setting the design direction, coordinating the architect, the permit application and the works delivered by our project team and selected specialists, and reporting to you until handover. You can read more about how we work.
In short
- An architect’s project is legally required when works change the structure, volume, exterior composition or use of the building.
- Minor interior works usually go through a declaración responsable; major works need a licencia de obra mayor with a technical project.
- The aparejador typically directs execution on site and handles health and safety coordination on many projects.
- Fees are agreed freely, so get a written proposal listing every stage included.
- On larger or more complex projects, an architect is often worth it even when not strictly required.
Planning a renovation on the Costa Blanca?
Tell us about your property. We design, coordinate and manage complete renovations on the Costa Blanca, from concept to completion.
General information for orientation, not legal, tax or technical advice. Rules vary by municipality — confirm specifics with the town hall, your architect or a qualified adviser.
