Do you need an architect or technical architect (aparejador)?

Terms used

• Proyecto — The proyecto is the technical project: drawings and specifications for the work, signed by a qualified technician.
• Aparejador — The aparejador, formally arquitecto técnico, supervises execution, materials, measurements and costs on site.
• Declaración responsable — The declaración responsable is a statement you file with the town hall that your minor works comply with the rules.
• Certificado final de obra — The certificado final de obra is the document, signed by the project's directors, confirming the work was finished as designed and licensed.

Key rules

• Project needed: New builds, works changing structure, layout or use, and works on protected buildings need a signed technical project.
• Minor works: Repainting or replacing floors usually needs only a declaración responsable or minor works licence.
• Final certificate: The director of works and the director of execution issue the final certificate together.
• Quotes: Fees are negotiated, so get several written quotes that list the services included.

Short answer

Small cosmetic jobs need no architect. New buildings and major works that change the structure, the layout of the building or its use need a technical project signed by a qualified technician. They also need a director of works and a director of execution. When the work is finished, those two professionals sign the final certificate.

What each professional does

The arquitecto (architect) writes the proyecto. The architect is also the usual director de obra, who oversees the work as a whole. This is the person you need for new builds and for works that affect the structure, the use or the outer shell of the building.

The arquitecto técnico, often called aparejador, is the director de la ejecución de la obra. This person controls the quality of materials, how the work is carried out, the measurements and the costs on site. An aparejador may also write the project for reforms that do not change the structure or use, and for interior works within their competence. The health and safety coordinator on site can be either profession.

Both professionals carry legal liability for the work. If you are unsure which one you need, ask for a quote from both.

Which works need a project

• new buildings;
• works on protected buildings.

These works also require a director of works and a director of execution.

Minor reforms, such as repainting, replacing floors or changing fittings, usually need only a declaración responsable or a minor works licence (obra menor). Sometimes a simple technical report is added. Each town hall sets its own rules on which licence applies, so the line between minor and major varies. Ask your town hall before you start.

The final certificate of works

The certificado final de obra states that the work was completed in line with the project and the licence. The director of works and the director of execution issue it jointly. The professional colleges may endorse or register it where that applies.

You will need it to:

• obtain the first occupancy licence or licence of use;
• register a new build or extension in the Property Registry through a notarial deed (declaración de obra nueva);
• take out the ten-year structural insurance;
• connect utilities;
• hold the reception act, when you formally accept the finished work.

Small works without a project do not normally need it.

What it costs

Fees are free and negotiated. For residential reforms, a project plus site supervision usually costs a percentage of the works budget. The percentage is higher for small jobs and falls as the budget grows. Complex or protected buildings cost more.

Professionals often quote separately for the project, direction of works, direction of execution and health and safety coordination. Some offer a fixed price. Get several written quotes that state exactly which services each one includes.

The documents and questions below cover the paperwork and common doubts.

Documents you need

• Technical project (proyecto), signed by a qualified technician, for new builds, works that change the structure, layout or use of a building, and works on protected buildings.

• Final certificate of works (certificado final de obra), issued jointly by the director of works and the director of execution once the work matches the project and licence. You need it for the first occupancy licence, the property registry entry for a new build or extension, decennial insurance and utility connections.

• Declaración responsable or minor works licence for small reforms such as repainting or replacing floors. Your town hall decides which one applies, and may ask for a simple technical report.

Frequently asked questions

Can an aparejador write the project for my reform?

Yes, an aparejador can write the project for a reform that does not change the structure or the use of the building. Interior works within their competence also fit. If the works touch the structure, use or outer shell, you need an architect.

Who signs the final certificate of works?

The director of works and the director of execution sign the final certificate together. These are usually the architect and the aparejador.

Do I need a final certificate for small works?

No, small works without a project do not normally need a final certificate. You need one for works with a technical project, such as new builds and major reforms. It is used for the first occupancy licence, the property registry entry for a new build or extension, decennial insurance and utility connections.

How much do architects and aparejadores charge for a reform?

Fees are free and negotiated, and they are usually a percentage of the works budget. The percentage is higher for small jobs and falls as the budget grows. Ask for several written quotes that say which services are included: project, direction of works, direction of execution and health and safety coordination.