Short answer: which licence and who applies
A pool at a house needs, in almost every town in the province of Barcelona, a llicència d'obres majors (major works licence). In Barcelona itself the ORPIMO lists the construction of pools and their ancillary buildings among major works. Castelldefels Town Council says the same on its website and adds that a licence is needed even for a prefabricated pool, because the planning parameters have to be justified.
The applicant is the property owner, but without a technical project signed by an architect or other qualified professional the application will not go through. You apply to the council of the town where the house stands: online through its Seu electrònica or, where allowed, in person by appointment. Each council sets its own documents and fees, so what follows are general principles with Barcelona and Castelldefels as examples. Rules change, so check your council's current procedure page before filing.
When a licence is needed and when there is more to it
A licence is needed for any in-ground pool: poured concrete, panel or prefabricated shell set into an excavation. In Barcelona earthworks (digging out, excavation, lowering ground) are major works too, so the pit alone is not minor work. If there are trees on the plot, the ORPIMO asks for a prior report from Parcs i Jardins (the municipal parks institute). A plant room, pergola or shower by the pool goes into the same project as ancillary buildings.
Seasonal inflatable or frame pools with no earthworks are not dealt with separately in the official texts reviewed; if in doubt, ask your council's planning information desk. A pool on the roof of a block of flats is load on the structure and on a common element: structural calculations, community approval and almost certainly a licence.
The key question for a house in Castelldefels or any other town is whether the local plan allows a pool on your plot and how far from the boundaries. Those parameters come from the municipal plan. In Castelldefels you can request a certificat de règim urbanístic (planning status certificate), which sets out what the plot allows and restricts.
What to prepare and who does it
In Barcelona the ORPIMO requires, for a pool, a technical project signed by a qualified professional: description, drawings, budget and annexes, including the health and safety study (or basic study) and an assessment of the volume and type of construction waste. For the licence the procedure page also asks for the reference number of an informe d'idoneïtat tècnica (IIT, technical suitability report), which the technician obtains from their professional association. If there are trees, the Parcs i Jardins report is added.
You provide the title deed or cadastral reference, the application details and, if you have it, the planning status certificate. The builder manages construction waste and gives you the delivery receipts, which you will need to close the file and recover deposits. The installer or engineer prepares the documents for pumps, filtration and the pool's electrical installation.
How to apply, step by step
Step one: find out what your plot allows, through the planning status certificate or a query to the council. Step two: commission the project from the technician. Step three, Barcelona: consulta prèvia on the Seu electrònica, then the licence application on the same portal, with identification and electronic signature (usually idCAT Mòbil, Cl@ve or a digital certificate) and the IIT number. The same person who ran the consultation must file. Step three, Castelldefels: major works application on seu.castelldefels.org with a digital certificate, or in person by appointment at Informació Urbanística; if a technician files, it must be online. The council itself advises requesting any ordenances fiscals rebates in the same application, with supporting documents.
Step four: payment. In Barcelona, after review, the City Council emails you the decision and the payment slip for ICIO and the fee; according to the City Council website in 2026, the major works licence fee is €385, or €4.96 per m² with a €385 minimum for new construction and added volume, and ICIO is 4% of the construction budget. The payment slip will show which rate applies to your pool. Once paid, the licence decree arrives by post with the start and completion deadlines. Other towns have their own rates, set in their ordenances fiscals.
After filing and after the works
In Barcelona the procedure page allows two months to decide a licence, or three if a fire service or heritage report is needed, plus whatever time you take to fix defects. You have one year to start and three to finish, unless the licence states otherwise. Keep the licence on site.
When the works end, file the closing documents: the technician's completion certificate and the waste delivery receipts. In Castelldefels the same papers are used to request the return of deposits. Then Catastro: the pool changes the property's description and is declared with form 900D, which can be filed online at the Catastro portal with a digital certificate. The usual deadline is two months from completion; check whether your council already reports the change to Catastro.
Before the first fill, check the drought status on the Agència Catalana de l'Aigua portal: in restriction phases the ACA bans or limits filling pools, and the phase is set per municipality.
Common mistakes
First: treating a prefabricated pool as minor work; Castelldefels states plainly that it needs a licence too. Second: digging before the licence is granted; excavation is already major work, and a stop order costs more than waiting. Third: not checking boundary distances and permitted plot coverage, and having to redo the project.
Fourth: losing the waste receipts and not getting the deposit back. Fifth: forgetting Catastro and later receiving a backdated IBI adjustment. Sixth: scheduling the first fill during an ACA restriction phase. Seventh: putting the pump room against the neighbour's fence without thinking about noise.
If you would rather not deal with it yourself, BCN YARD can take over the paperwork together with the build.