Short answer: which permit you need
Windows facing the street or the inner courtyard are part of the facade, so in Barcelona replacing them almost never qualifies as an assabentat (simple notice for minor works). Under the Ordenança reguladora dels procediments d'intervenció municipal en les obres (ORPIMO, the bylaw on municipal control of building works), that route only covers interior works that do not change layout, structure or facade. Restoring, modifying or repairing facades on an unprotected building is minor works type II, which means a comunicat immediat (immediate notice). If the building is protected, the procedure is stricter and can go all the way to a llicència d'obres majors (major works licence).
You can file it yourself on the City Council's Seu electrònica, but a comunicat needs a qualified technician to prepare the documents and obtain the informe d'idoneïtat tècnica (IIT, technical suitability report). The consulta prèvia (prior consultation) gives you the exact procedure for your address. Rules change, so check the current procedure page before you file.
Which procedure for which protection level
The ORPIMO sorts buildings by protection level. For an ordinary unprotected building, facade works including windows are minor works type II: a comunicat immediat. For level D buildings and buildings inside protected ensembles, facade works are type I, a comunicat diferit (deferred notice), and the City Council has one month to review. For level C buildings, routine upkeep and minor repairs that do not touch the protected elements stay in type II; anything else on the facade needs a licence. For level A and B buildings, any facade work beyond routine upkeep or minor repair goes through a major works licence.
For a single-family house, the ORPIMO treats facade work with no added volume and no change of use as type II. The final answer for your address always comes from the consulta prèvia, so check the protection level before you choose the windows.
What you may change and what you may not
The Ordenança dels usos del paisatge urbà (OUPU) requires the facade's architectural composition to be kept. Railings, shutters and awnings within one building must stay uniform in colour, material, texture and shape, and changing the composition is banned except to restore the original design. Even the city's criteria for AC units fitted into a window opening insist on keeping the original frame division and colours. In an Eixample building with timber balcony doors and louvred persianes, the new windows must repeat the pattern, colour and opening type; swapping dark timber for white PVC will almost certainly be refused.
There is also the civil-law side. Under the Codi civil de Catalunya you may renovate your flat as long as you do not alter the building's configuration or exterior appearance; you must tell the community's president or property manager beforehand, and works that touch common elements need a resolution of the owners' meeting. Show the community a sample before you order the windows, especially if the colour or profile changes.
Upper floors have their own OUPU article. All openings on the upper floors of a facade may only have one system of frames and shutters, identical in position, design, material and colour, and only in one of three cases: the original frames are kept; they are restored to their original position and colour; or a works licence is obtained for a global architectural project covering the facade. The same article bans reflective glass and bringing the frame forward to turn a balcony or terrace into indoor space. In other words, enclosing your balcony while you change the windows does not fit these rules.
For a detached house, say in Castelldefels, the OUPU does not apply, but the town has its own facade rules; ask at its planning information desk.
What to prepare and who does it
For work on the facade of an unprotected building, the ORPIMO asks for a technical project signed by a qualified professional with description, drawings and budget; responsible declarations from the works director and the site execution director; colour photos of the facade; and a health and safety study or basic study, with the safety coordinator appointed. The technician (architect or technical architect) prepares the project and declarations and obtains the IIT from their professional association.
You provide the cadastral reference, photos, details of the flat and the community's resolution if needed. The window maker supplies the technical data sheet: thermal transmittance, air permeability, colour and profile section. You will use that data twice: for the project and for grants or tax relief, where the windows must meet the limit values of the Código Técnico (DB HE-1).
How to file, step by step
Start with the consulta prèvia on the City Council's Seu electrònica: enter the address and type of work and you get the procedure, the document list and a consultation number. The same person must then file, because the number is tied to their ID. Next the technician prepares the project and the IIT. Then you file the comunicat on the Seu electrònica: identification (usually idCAT Mòbil, Cl@ve or a digital certificate), form, files and electronic signature. If your technician files for you it will always be online, because professionals must file electronically.
With a comunicat immediat, once the documents are accepted you pay ICIO and the fee online or at a partner bank; according to the City Council website in 2026, ICIO is 4% of the construction budget, and the fee and any rebates are set in the current ordenances fiscals. Once paid, you can start. With a comunicat diferit you wait up to a month for either the admission with a payment slip or an avís d'ineficàcia listing the defects. With a licence, the procedure page gives two months to decide, or three if a heritage report is needed.
After filing: deadlines, site and money
Keep the comunicat admission and proof of payment on site. The payment slip is valid for three months, and comunicat works must be finished within six months of the start date in your application. If the project changes during installation, a comunicat needs a new filing with an updated IIT.
On money. The Consorci de l'Habitatge de Barcelona programme, which paid up to €6,000 for new windows, required works to be finished before 30 June 2026, so now watch the Consorci website for new calls; those grants measured the improvement with an energy certificate before and after. For income tax, the Agencia Tributaria offers a 20% deduction (maximum base €5,000) for works in your main home that cut heating and cooling demand by at least 7%, for amounts paid up to 31 December 2026, with the energy certificate issued before 1 January 2027. Check the conditions before you order, not after. The Institut Municipal del Paisatge Urbà also runs a 2026 call: for buildings of heritage interest it funds 30% (up to €20,000) of restoring openings and making frames and shutters uniform. Requests for the technical report are accepted until 16 November 2026 unless the budget runs out earlier, finished works are not eligible, and the community usually applies.
Common mistakes
First mistake: filing new windows as an assabentat because the job looks small. Facade windows do not fit that route, and if there is an inspection the works will lack the proper permit. Second: ordering windows in a different colour or with a different frame division without reading the OUPU or asking the community. Third: not checking the building's protection and filing a comunicat immediat where a comunicat diferit or a licence was needed.
Fourth: removing the old frames before paying ICIO under a comunicat immediat, or before the admission under a comunicat diferit. Fifth: skipping the energy certificate before the works and then losing the grant or tax deduction. Sixth: using Barcelona's rules for a house outside Barcelona.
If you would rather not deal with it yourself, BCN YARD can take over the paperwork together with the renovation.