Short answer: three desks and who does what
A self-consumption solar system goes through three stages. First, the works permit from the City Council. In Barcelona, for a standard rooftop system, the Energia Barcelona guide speaks of an assabentat (notice) or a comunicat immediat (immediate notice) depending on whether the structure is affected; the consulta prèvia gives you the exact route. Second, the electrical legalisation, done by the installer, and entry in the Registre d'autoconsum de Catalunya (RAC, the Catalan self-consumption register), which the owner requests. Third, tax breaks: IBI and ICIO rebates from the City Council and the new 2026 income tax deduction.
Much of the paperwork is handled, by law or by habit, by the installer and the technician, yet you can keep control and file the RAC request and the IBI rebate yourself. Rules change, so check the current page of each procedure before filing.
Which permits you need and when
A block of flats in the Eixample. The roof is shared, so the community decides first. The Codi civil de Catalunya lets owners approve by simple majority renewable energy systems on common elements, both for shared use and for the private use of owners who request them, even if the exterior changes. Next comes the city permit. If the building is catalogued, the landscape bylaw requires a municipal licence for such equipment, and the City Council publishes rooftop integration criteria: low solutions, set back from the facade edge, with limited height above a flat roof.
A house in Castelldefels. The OUPU and ORPIMO do not apply; the town sets the rules, and many Catalan towns handle rooftop panels by comunicació prèvia (prior notice), but confirm it with the planning information desk. Ask too whether the town offers an IBI rebate: ICAEN runs a search tool listing municipalities that do.
The electrical side is the same across Catalonia. A system of up to 15 kW on urbanised land needs no grid access and connection permit; between 15 and 100 kW it does. Up to 10 kW a technical report is enough; above that you need a project signed by a qualified professional.
What to prepare and who does it
You, as owner: cadastral reference, the community's approval with the meeting minutes if the roof is shared, the installer's contract and an itemised invoice (for the IBI rebate the City Council wants the invoice in its own template), and the surplus compensation agreement with your electricity retailer. If you rent, the Energia Barcelona guide notes that you must be the owner or have the owner's consent.
The qualified technician: documents for the city permit, a check that the roof can carry the load, and the certificat de direcció i finalització d'obra (works management and completion certificate), which is used both for the RAC and for the IBI rebate.
The installer: installation under the low-voltage regulations, the certificat d'instal·lació elèctrica (CIE, electrical installation certificate), the declaració responsable (responsible declaration) for the low-voltage installation so it is entered in RITSIC, and the technical report for the RAC. Above 15 kW, or outside urbanised land, the installer also obtains the connection permit and technical contract from the distribution company.
How to process it, step by step
Step one: have the roof assessed and get two or three installer quotes. Step two: obtain the community's approval. Step three: in Barcelona, run the consulta prèvia on the Seu electrònica and file whatever it indicates, identifying yourself with idCAT Mòbil, Cl@ve or a digital certificate; if it is a comunicat, pay ICIO and the fee before work starts. Step four: installation.
Step five: the installer files the low-voltage responsible declaration with the Generalitat, which is a prerequisite for the next step. Step six: for a system with surplus compensation, the owner requests the autorització d'explotació definitiva (final operating authorisation) on Tràmits gencat; systems without surplus export have a separate Generalitat procedure. It is online only, with idCAT Mòbil or a digital certificate, attaching the technical report or project, the completion certificate and, where required, the contract with the distribution company. It must be requested before the system goes live and it is free. Once submitted you receive an ID by email to track the status on Canal Empresa or by calling 012.
Step seven: sign a surplus compensation agreement with your electricity retailer so that the energy you export reduces your bill.
After filing: response, rebates and tax credit
The Generalitat checks the data within three months at most. If everything is correct it issues the RAC registration document, which you download from your private area on Canal Empresa. If not, it issues a rejection notified electronically; you have 10 calendar days to open the notice and one month to appeal.
According to the City Council's Energia Barcelona website in 2026, voluntary systems on residential buildings get a 50% IBI rebate for the first three years after the investment and a 95% ICIO rebate; the bylaw sets a minimum power per dwelling. You apply for the IBI rebate at the Institut Municipal d'Hisenda with the works notice admission, the ICIO self-assessment, the installer's invoice in the official template, the completion certificate and the RAC request receipt; for shared systems, also the community minutes with the cost split.
Income tax: Real Decreto-ley 7/2026 lets you deduct 10% of what you pay for a self-consumption system on property you own, or 20% for dwellings in predominantly residential buildings. The maximum base is €5,000 a year; the system must be installed, finished and paid for in 2026, not in cash, with a CIE; grants are subtracted from the base, and it cannot be combined with the energy efficiency deductions for the same installation.
Common mistakes
First: switching the system on without having requested the RAC entry. The procedure page requires the request to be filed before start-up. Second: paying the installer in cash, which rules out the income tax deduction. Third: not getting the completion certificate from the technician; without it neither the RAC nor the IBI rebate goes through.
Fourth: installing panels on the shared roof without the community minutes. Fifth: not checking whether the building is catalogued, where a licence is required. Sixth: counting on Barcelona's rebates for a house outside Barcelona; every town has its own ordenances fiscals. Seventh: leaving the job for December and failing to finish and pay in 2026, the year the new deduction applies.
If you would rather not deal with it yourself, BCN YARD can take over the paperwork together with the renovation.