A lot of work goes into renovating a home from planning to execution, but before you begin you need to know whether your project legally requires a construction permit.

Depending on the scope of your renovation, you may need to apply for one that covers minor or major works or submit a declaration of responsibility.

Each permit will determine how soon you can start work, how much tax you’ll pay, whether you need an architect and the kind of legal risk you are taking on.

While the bureaucratic process can be a headache, our guide will explain the differences and help you determine which permit, if any, you need to make sure your project complies with Spanish construction law.

• When you don’t require a permit
• What is a Declaración Responsable?
  • What do I need for a Declaración Responsable?
  • How much does a Declaración Responsable cost?
• What is an Obra Menor?
  • What do I need to obtain a Licencia de Obra Menor?
  • How much does a Licencia de Obra Menor cost?
• What is an Obra Mayor?
  • What do I need to obtain a Licencia de Obra Mayor?
  • How much does a Licencia de Obra Mayor cost?

When you don’t require a permit

Some simple, low-impact renovations do not normally require a building licence if they don’t affect the structural elements or protected features. Additionally if you live in a shared building, so long as your changes aren’t affecting any common areas, you may not require a permit.

The kind of work that doesn’t require any kind of licence includes:

• Painting interior walls
• Replacing floor tiles or sanding parquet
• Swapping out internal plumbing or electrical features that don’t alter the layout

However, even small jobs might require permission if they impact protected or shared areas; always confirm with your local ayuntamiento before beginning.

What is a Declaración Responsable?

A declaración responsable allows certain minor works to begin immediately after submission, without waiting for a full licence, provided all requirements are met.

This document can be suitable for:

• Interior refurbishments without structural changes
• Installing air conditioning or heating
• Changing windows or doors
• Upgrading plumbing or electrics (without layout changes)

While you can start work immediately after submitting your declaration, you are legally responsible for full compliance and the ayuntamiento will be able to inspect works after submission. If they are found to be non-compliant you may have to pay a fine and could be ordered to halt or undo the work.

The types of works that qualify for a declaración responsable vary between municipalities, so be sure to check with the local ayuntamiento before proceeding; in some cases a Licencia de Obra Menor may be required for the same type of work.

What do I need for a Declaración Responsable?

• Official self-declaration form issued by the relevant municipality
• Detailed cost estimate for the construction work
• Receipt confirming payment of the applicable local government fee
• Measured drawings or diagrams outlining the nature of the project
• Confirmation by the technician agreeing to oversee the construction work
• Preliminary report on workplace health and safety considerations
• Written description outlining the scope and nature of the construction

How much does a Declaración Responsable cost?

The cost of submitting a declaración responsable typically includes an administrative fee of €100–€500 and the ICIO tax, usually around 4% of the project budget (PEM).

What is an Obra Menor?

An obra menor applies to simple, technical and low-cost works that don’t affect the structure of the building and usually improve the functionality or aesthetics of a home, such as:

• Renovating kitchens or bathrooms (without layout changes)
• Installing air conditioning units
• Minor plumbing or electrical modifications
• Painting building exteriors

Most municipalities require a licencia de obra menor before beginning these projects; if in doubt, don’t hesitate to contact your local ayuntamiento.

What do I need to obtain a Licencia de Obra Menor?

• Copy of DNI or NIE
• Completed request form specific to the procedure
• Receipt showing payment of the applicable tax and municipal charge
• Address of the construction site
• Site plan
• Description of proposed renovation work
• Detailed cost breakdown, formatted as if drafted by a certified technician

Typically obtaining a permit for an Obra Menor is quicker than an Obra Mayor, and may be completed within a week, but this can vary depending on the ayuntamiento.

How much does a Licencia de Obra Menor cost?

A licencia de obra menor usually costs between 3–5% of the PEM, which includes the ICIO and other municipal fees.

What is an Obra Mayor?

An obra mayor covers large, complex or structural building projects. These works require a technical project to be prepared by a licensed architect and will need to be approved by the technical office of the ayuntamiento.

Typically the kind of work covered by a licencia de obra mayor includes:

• Structural alterations like moving load-bearing walls
• Building extensions or adding floors
• New constructions
• Changes to building use
• Demolition
• Anything that involves fire safety or shared structural elements

In short, any structural or substantial work that changes a building’s layout or use will require a permit for obra mayor.

Typically it will take 3–12 months to obtain the permit depending on the council’s capacity and the complexity of the project. If approved, you must begin the work within 12 months and complete it within 3 years, unless stated otherwise.

What do I need to obtain a Licencia de Obra Mayor?

• Application form
• ID document (DNI) of the applicant
• Authorisation certifying representation by a technician (if applicable)
• Proof of payment of the applicable fees
• Technical Project endorsed by the Official College of Architects

Contents of the technical project must be submitted in triplicate:

• Digital cartographic plan
• Location plan
• Pre-construction plan
• Budget by units with updated market prices
• Descriptive and justificatory report of the works
• Expected duration of the works
• Anticipated start date from the time the municipal licence is obtained
• Explanatory report and annexed fire prevention plans
• Installation plans
• Specifications document (pliego de condiciones)
• Waste management study

How much does a Licencia de Obra Mayor cost?

For a licencia de obra mayor, you can expect to pay 2–6% of the PEM, including the ICIO (around 4%) and other municipal charges—excluding VAT and architect’s fees. Additionally, you will need to pay architect’s fees which depend on the project scope.

There are also penalties for non-compliance which can range from €300 to over €6,000 and you may even be ordered to undo unauthorised work.