Before knocking down a wall, replacing a bathtub with a shower, or painting a facade, there is one key question that dictates everything that follows: is this a minor or major building work? The answer does not depend on the cost of the renovation or how long it takes; it depends on what is being altered. Confusing these two categories is one of the most costly mistakes homeowners make, despite having the best intentions, when planning improvements to their property.

The General Rule: It Depends on What Is Altered, Not the Cost (and Regulations Vary by Region)

Here is an important warning before proceeding: there is no single statutory definition across Spain. Each autonomous community has its own town planning legislation, and each local council subsequently establishes its own procedures within that framework. The guidance set out below reflects general criteria rather than a uniform rule applicable in every municipality.

That said, as a general rule, works affecting the structural integrity, the building envelope (facades, roofs), or involving a change of use are usually processed as major works. These require a formally endorsed technical project and professional supervision. Conversely, works modifying finishes or utilities without affecting the building structure typically fall under a minor licence or a more streamlined procedure. Prior to commencing any work, the most prudent course of action is to consult the relevant municipal council where the property is located, or a qualified surveyor, to determine the precise requirements for your project, rather than assuming general criteria apply universally.

On the Costa del Sol, this involves an additional nuance worth keeping in mind. The region encompasses nine municipalities (Benalmádena, Torremolinos, Fuengirola, Mijas, Marbella, Benahavís, Estepona, Casares, and Manilva), each with its own planning bylaws. It is common for these councils to publish guidance notes or interpretive criteria to clarify how their regulations are applied (for instance, concerning setback requirements, boundary clearances, or which works fit into each administrative procedure), and these criteria may be updated over time. Furthermore, many properties are situated close to the coastline, where the Coastal Law (Ley de Costas) may impose supplementary restrictions. Therefore, before initiating a renovation in Benalmádena, Mijas, Fuengirola, Marbella, or any other local municipality, it is advisable to check the exact requirements of the specific council rather than assuming that the rules of a neighbouring authority will apply.

Prior Communication, Minor Licence, or Major Licence: The Three Pathways

Replacing a Bathtub with a Shower, Painting the Facade, or Enclosing a Balcony: The Most Common Doubts

Certain renovations appear straightforward yet end up categorized differently than anticipated:

• Replacing a bathtub with a shower while retaining the existing layout and plumbing arrangement generally falls under a responsible declaration. However, if the shower tray is relocated with new drainage, it may require a minor licence.
• Replacing a gas boiler with an air-source heat pump, accompanied by modifications to the electrical consumer unit, usually requires a minor licence due to the alteration of regulated installations.
• Painting the external facade, even without structural changes, typically requires a prior communication or minor licence, as it affects a communal element and the street scene rather than solely private property.
• A kitchen renovation that moves non-structural partition walls generally remains a minor work in many municipalities. Only if the alteration affects structural elements, or falls under specific provisions set by local bylaws, will it require processing as a major work. Moving walls does not automatically equate to major works; it depends entirely on whether the walls are load-bearing and the specific local regulations.
• Enclosing a balcony or terrace with glazed framework usually requires a licence, even if viewed by the owner as an internal improvement, because it alters the facade and the external volume of the building.

Processing Times Framework

As a general guide, and without prejudice to direct enquiries with the relevant local council: a responsible declaration typically allows work to start immediately upon submitting complete documentation, where local regulations permit. Minor licence applications are generally determined within a few weeks to two months, depending on the authority. Major licences usually take several months, particularly when statutory reports from third-party bodies (such as heritage or environmental authorities) are required.

ICIO: The Tax Due Regardless of Licence Approval

The Tax on Construction, Installations, and Works (Impuesto sobre Construcciones, Instalaciones y Obras – ICIO) becomes payable upon undertaking works that require a licence, responsible declaration, or prior communication, regardless of whether approval is ultimately granted. The rate is set by each municipal authority up to a legal maximum of 4% of the material execution budget (Presupuesto de Ejecución Material), meaning the actual cost varies considerably between areas. Many councils offer tax relief (often between 50% and 95%) if the works demonstrably improve energy efficiency, making it worthwhile to verify potential relief before discounting a project on tax grounds.

By way of example: for a renovation with a material execution budget of €20,000, a 3% tax rate (typical in many mid-sized municipalities) incurs €600 in ICIO. This is in addition to the administrative application fee, which is a separate charge.

Consequences of Non-Compliant Works

Carrying out works without the correct administrative procedure (or under a lower classification than legally required) may result in financial penalties, stop notices, or, in severe cases, demolition orders if the works cannot be regularized. Where regularization is possible, property owners are generally permitted to submit a retrospective planning project, albeit subject to a fine ranging between 10% and 50% of the material execution budget, depending on the severity and local regulations.

Regarding tacit administrative consent (silencio administrativo) for major licences, caution is advised: the application of tacit consent in planning matters depends on the applicable statutory framework and the nature of the application. In certain circumstances, particularly those involving protected land or restricted uses, positive tacit consent does not apply. Before assuming an application has been granted or refused merely through the expiry of a statutory deadline, the status of the file should be formally verified with the local authority.

This has direct implications for prospective sellers: recent unapproved or misclassified renovations can manifest as significant obstacles during pre-completion legal searches.

Social Housing (VPO): Additional Compliance Checks

If the property is designated as social housing (Vivienda de Protección Oficial), it is advisable to check whether additional authorizations or formal notifications are required beyond municipal consent. This depends on the specific protection scheme, the age of the property, and the scope of the works. In Andalusia, certain alterations to social housing may require formal notification to AVRA (Agencia de Vivienda y Rehabilitación de Andalucía), even where unencumbered private properties would require no such step. Specific requirements should be confirmed directly with AVRA prior to starting work.

Requirement for Homeowners’ Association Approval

An additional regulatory layer is frequently overlooked: securing a municipal licence does not guarantee compliance regarding the homeowners’ association (comunidad de propietarios). If works affect common elements of the building (facades, visible balcony enclosures, shared structures), formal consent from the association is generally required under the Horizontal Property Act (Ley de Propiedad Horizontal), adhering to the requisite voting majorities. Crucially, holding a municipal licence does not prevent the association from legally requiring the restoration of a common element to its original state if the alteration breaches the Horizontal Property Act or community bylaws. These represent two distinct authorizations; one does not supersede the other.

Summary Checklist Before Proceeding

Before fixing a start date for any renovation, consider the following four points:

• Confirm whether the proposed works are classified as minor or major based on the scope of the intervention, rather than estimated cost or duration.
• Review the current bylaws of the municipality where the property is located at the time of the works, rather than relying on regulations applied previously or in neighbouring districts.
• Obtain formal homeowners’ association approval if the works affect any communal elements.
• If intending to market the property, resolve all planning and building documentation prior to listing, rather than after receiving an offer.

If renovating a property prior to sale, auditing the planning documentation beforehand can prevent delays, price renegotiations, or transaction failures.

Require professional advice before renovating or selling? Contact us: +34 692 62 19 19.