Since 3 October 2026, selling or letting a property in Catalonia involves a new step: stating whether or not there is asbestos in it.

With the entry into force of Law 8/2026, of 2 July, on the eradication of asbestos, the certificate of presence or absence of asbestos joins the documents that must be handed over in sales and rentals. Until now it was not part of the usual paperwork for a home or commercial premises, and it particularly affects buildings constructed when fibre cement and other asbestos-containing materials were in everyday use.

And, as usually happens when a new regulation comes into force, all sorts of claims are going around these days: fines of up to €100,000, certificates that supposedly anyone can sign, or the idea that if you have uralita (asbestos-cement sheeting), you have to remove it before you sell.

But what does the new law actually require? Who can issue the certificate? Does the property need to be inspected? And what happens if asbestos is found?

At Nomadas Architecture we are architects and we can prepare this certificate. In this article we explain clearly what the new law already requires, which criteria the Agència de Residus de Catalunya (the Catalan Waste Agency) is applying while the implementing regulation is drafted, and which questions are still to be settled. If you are going to sell or let a home or commercial premises in Catalonia, this is what you need to know.

The essentials:

• Since when: the obligation has applied since 3 October 2026 to any sale or rental of a property located in Catalonia.
• Who signs it: the law leaves this to a regulation; in the meantime, the Agència de Residus accepts professionals qualified under the LOE (Spain’s Building Act), including technical architects.
• Fine: failing to hand it over is a minor offence (€100 to €3,000), but the penalty scale depends on a decree that does not exist yet.
• Removal: you do not need to remove the asbestos to sell or let. The law requires you to disclose it.
• What the law does not set: the price, how long the certificate is valid, or a cut-off by year of construction.

What the certificate of presence or absence of asbestos is

It is a document that states whether a property contains asbestos and, if it does, what condition it is in and what risk it poses. A technical professional issues it after inspecting the building or home, and it reflects what was there on the date it was issued. It works like a dated snapshot and does not update itself if the condition of the materials changes later. It informs; it does not remove anything or require laboratory analysis. It is also a separate document from the energy performance certificate: if you sell or let, you need both.

Until now, asbestos-containing materials installed before the 2001 ban could stay in place until the end of their service life, with no legal obligation to remove or declare them. The Catalan law changes that starting point. It stems from a July 2024 report by the Síndic de Greuges (the Catalan Ombudsman) and is aligned with the European goal of eliminating asbestos from buildings by the end of 2032 (2028 for public buildings). The certificate is the piece that makes the problem visible at the moment a property changes owner or tenant.

It is one more document in the transaction, like the energy certificate or the land registry extract (nota simple) you use to check whether a property has outstanding debts.

What Article 21 of Law 8/2026 says

Article 21 of Law 8/2026 defines the certificate as a “specific document that reports on the presence or absence of asbestos in a property at the time it is issued” and adds that it fulfils the disclosure obligation set out in the law. If you are going to sell or let, these are the points that affect you:

• When it is handed over: when a property is sold or let (Art. 21.2). The owner or landlord provides it.
• Relationship with the Catalan Asbestos Census: handing it over is “without prejudice” to consulting the data in the Catalan Asbestos Census (Art. 19), which is a separate register.
• Content: Art. 21.3 sets a minimum, which covers visible asbestos only, and leaves the certificate’s characteristics and who can issue it to the regulation.

Since when it is mandatory and which properties it covers

3 October 2026: what is already in force

Law 8/2026 was published in the DOGC (the Official Gazette of the Government of Catalonia) on 3 July 2026 and, under its seventh final provision, comes into force three months later. That is why the obligation to provide the certificate has applied since 3 October 2026 to any sale or rental of a property located in Catalonia, and buyers and tenants can demand it from that same day. The law was also published in the BOE (Spain’s Official State Gazette) no. 201 of 17 August 2026 (some guides say “17 July” by mistake).

The penalties chapter (Arts. 49 to 58) depends on a later decree, as explained in the section on penalties.

Homes, commercial premises, offices and industrial units, each one separately

Article 21 refers to “a property” and does not distinguish between uses. It covers flats, detached houses, shops and commercial premises, offices and industrial units, regardless of where the estate agency or the owner is based. What counts is that the property is in Catalonia.

For an individual unit, such as a flat or an office within a building, the Agència de Residus states that the certificate refers only to that unit. If you are selling your flat in a 1970s block, you do not need to certify the whole building or reach an agreement with the owners’ association. If you sell two flats, or a flat and a commercial unit, they are separate certificates.

If your building dates from after 2002

The law sets no cut-off by year of construction. Article 21 requires the certificate when a property is sold or let, whatever year it was built.

The cut-off comes from the administration. In its model certificate, the Agència states that it is required for properties built before 2002. The date makes sense: an Order of 7 December 2001, which amended Royal Decree 1406/1989, banned the marketing of asbestos in Spain. That ban applied to the production and sale of materials, not to those already installed.

I would treat 2002 as a reasonable reference point, not as an exemption written into the law. A building completed in 2003 may have been built with materials bought before the ban, and a later renovation may have kept older elements. If your property is more recent, check with a technical professional before assuming you need nothing, and keep a written record of the criterion used to rule it out.

What is still pending regulation

The law sets out the obligation, the minimum content and the offences regime, but leaves quite a few details to a regulation. The first final provision gives the Govern (the Catalan Government) one year from the law’s approval (until July 2027 at the latest) to regulate, among other things:

• The characteristics of the certificate and who can issue it.
• The data in the Asbestos Census: what information must be included and how it will be reported.
• The requirements for collaborating entities involved in its management.
• The bodies responsible for penalties and the criteria for coercive fines.

In addition, the Register of qualified companies and professionals must be created within six months of the law’s entry into force, which makes April 2027 the deadline. July and April 2027 are maximum deadlines, not confirmed dates for publishing the regulation. When it is published, it could also settle questions the law currently leaves open, such as the cut-off by year of construction or how long a certificate remains valid.

Who must provide it, to whom and when

The certificate is provided by whoever is selling or letting. Other people are involved in the transaction (property managers, estate agencies, the notary), but the obligation is theirs alone.

Owner or landlord, buyer or tenant

Art. 21.2 states that the owner hands the certificate to whoever buys or rents the property. From the other side, Art. 5.d lists obtaining it “under the legally established terms” as a right of citizens, so if you are buying or renting you can ask for it with the law on your side.

On timing, the law says little. It states that it is handed over “when a property is sold or let” and does not specify whether this must happen before the listing, before the deposit contract (arras) or on the day of signing. Nor does it set how delivery is proven; that is left to the regulation, and in the meantime it is wise to keep written proof, for example a signed receipt or a mention in the contract.

I would have it done before publishing the listing, which is also what several industry guides recommend (as advice, not as a legal rule). If the report finds uralita on the roof or in a downpipe, you know before negotiating the price, not halfway through the deposit contract.

If you are on the buying side, ask for it before signing the arras, while you can still weigh what any findings mean, as with the other technical checks we cover in how an architect can advise you when buying a home.

The role of property managers, estate agencies and the notary

Property managers (administradores de fincas) are the only ones in this group to whom the law gives an explicit task regarding the certificate. Art. 12.1.b requires them, along with “other related professionals”, to “ensure that owners of homes or properties hand over a certificate of presence or absence of asbestos-containing materials to the person who buys or rents the property, and to assist them in obtaining that certificate”.

The obligation still lies with the owner; the property manager ensures and assists. In practice, they can help you gather the building’s documentation or coordinate access to roofs and shared courtyards for the technical visit. Art. 12.1 also asks them to report any asbestos they know of to the owner and to the Census (letter a) and to provide information on available grants (letter c).

Estate agencies and notaries are a different matter, because the law does not name them as obliged to provide or check the certificate. The expression “other related professionals” in Art. 12 is open-ended and some guides extend it to estate agents, although the text does not say so. To be on the safe side, it makes sense for the agency to ask you for it when you instruct them to sell, and for the certificate to reach the notary with the rest of the documentation, so that its delivery is recorded in the deed or the contract.

Sale and rental listings: disclosing presence or absence (Art. 10.h)

Art. 10.h requires that, “in the context of a consumer relationship, the presence or absence of asbestos-containing materials be disclosed to consumers in any offer, promotion or advertising for the sale or rental of homes, in accordance with what is stated in the certificate”.

Many guides read this as an obligation for property portals and estate agencies to state it in every listing. However, Art. 10 is addressed to companies and professionals engaged in activities related to the management and removal of asbestos. Applying it to portals or estate agencies is one possible reading, not an express provision, and the regulation will need to clarify it. If you already have the certificate when you publish, you can state in the listing what it says (presence or absence, and where) without waiting for that interpretation to be settled.

What it must include and how the inspection is done

Minimum content: visible asbestos, state of repair and risk to people

Article 21.3 sets what any certificate must cover, at a minimum:

• Presence or absence of visible asbestos, meaning what the professional can see in the property on the day of the visit.
• State of repair of any asbestos-containing materials, if there are any.
• Risk to people, or what real danger that material poses as it is and where it is.

In practice, the document usually also includes the property details, the identity of the professional who signs it and photographs of the elements inspected.

The law does not explain how that condition or that risk is measured, because that is left to the regulation. It does give a clue in Article 2.h, which defines potential risk according to the material’s degree of deterioration and the surrounding conditions. An intact fibre-cement sheet on a roof nobody goes up to does not pose the same risk as a cracked downpipe in a courtyard where the washing is hung out every day.

Until the regulation arrives, the Agència publishes a basic model certificate of presence or absence of visible asbestos, free and in Word format, for qualified professionals to use.

What an architect’s visit involves: where we look and how condition is assessed

The law does not describe the visit either. In practice it means going over the elements where asbestos was most often used, checking their condition and documenting it so the certificate can be justified. The document should also record any areas that could not be accessed, because what cannot be seen is not covered.

There is a published technical reference for assessing condition and risk. The methodology for assessing the potential risk of installed asbestos-containing materials published by the INSST (Spain’s National Institute for Occupational Safety and Health), document DD.138.1.25 from 2025, scores four factors:

• Characteristics of the material: type of product and how it is made.
• Ease of fibre release: whether it is compact or whether it crumbles, cracks or is eroded.
• Surroundings: where it is installed and what it is exposed to (weather, knocks, vibration).
• Likelihood of people being exposed: how many people pass close by and how often.

That score places the material in a risk level. The method was designed for the workplace and Law 8/2026 does not require it, but I think it is a good reference for giving “state of repair” and “risk” an objective basis, and it fits the deterioration and surroundings criteria in Article 2.h.

Roofs, downpipes, tanks, ducts, floors and insulation

In properties built before 2002, these are the elements most often checked:

• Roofs: corrugated uralita sheets on roof terraces, garages, storage rooms and industrial units.
• Downpipes and flues: fibre-cement pipes, often in light wells or on rear façades.
• Water tanks: the fibre-cement tanks on flat roofs and rooftops.
• Ventilation ducts: also fibre cement in many buildings from that period.
• Floors: some old vinyl flooring.
• Thermal or fire-resistant insulation: more common in industrial units and commercial premises than in homes.

For each element, the inspection checks whether the material is intact or whether it has breaks, chips or eroded surfaces. When intact, it usually poses a low risk; when broken, drilled or cut, which is what happens during a renovation, it releases fibres. That is also why the professional should ask about previous work, such as a downpipe cut to run a service through or a roof patched in sections.

Visual inspection versus sampling and laboratory analysis

The legal minimum is met with a visual inspection, and the law does not require laboratory testing. By eye, a professional can identify a material as compatible with asbestos from its type, its appearance and the period of construction. Confirming that it actually contains asbestos requires taking a sample and having it analysed in a laboratory.

Sampling is an additional service, with its own cost. It is usually worthwhile in two cases:

• When you are going to renovate and the work will affect a doubtful material.
• When the presence or absence of asbestos in a specific element weighs on a purchase decision or a negotiation.

If your certificate is based only on a visual inspection, it is reasonable to ask for the document to say so explicitly, so whoever reads it knows what has been checked and what has not.

Hidden asbestos: what a visit does not see

Article 2.i, when defining the census of assets containing asbestos, refers to materials that are “visible, camouflaged or hidden”. As the certificate covers only what is visible, anything behind a false ceiling, inside a built-in downpipe or under a floor falls outside the minimum, unless the professional extends the survey.

That asbestos can be inside cavity walls, in concealed ducts or behind wall finishes, and often only appears when things are opened up, sometimes in the middle of building work. That is why a certificate of absence does not guarantee the property is asbestos-free. If you are buying to carry out a full renovation, it makes sense to ask for a broader survey before closing the deal, just as you would with a technical home inspection report to find out the property’s real condition.

Who can sign it and how to get one

Architects, technical architects and engineers: what the rules say

The law does not name any profession. Article 21.3 of Law 8/2026 states that “the characteristics of and competence for issuing the certificate of presence or absence of asbestos must be determined by regulation”, and that regulation does not exist yet.

Until it arrives, the Agència has set a criterion for the transitional period. On its page about the model certificate, it states that it can be issued by any professional qualified under the Building Act (LOE), always “according to their competences”:

• Architects.
• Technical architects.
• Engineers and technical engineers.

This is the reading of the body that manages the certificate, not the text of the law, and the regulation could specify or narrow it. The Col·legi d’Arquitectes de Catalunya (the Catalan Association of Architects) also takes it as given that this regulation will set the qualifications required to issue it.

The Agència’s basic model is a template for a professional to sign after visiting the property, and each section depends on what is observed during the visit, so downloading it and filling it in yourself does not count as a certificate.

Steps to request it, what documents to prepare and what to get from the professional in writing

1. Pin down which unit needs certifying: flat, commercial unit or industrial unit.
2. Ask a qualified professional for a quote: explain the type of property, its approximate year of construction and whether you are selling or letting. There are more criteria on who to entrust it to in how to choose a good architect.
3. Gather what you have on the property: ask the professional what they want to see before the visit. If you have paperwork from previous work (a roof replacement, replaced downpipes, a uralita removal), keep it to hand.
4. Provide access on the day of the visit: roof, storage room, meter room or any space with old installations. What cannot be seen is not reflected.
5. Review the certificate before handing it over, to check that it corresponds to your property and covers what you agreed.

Before commissioning it, ask for the following to be set out in writing in the quote or in the certificate itself:

• Scope: whether it will be a visual inspection or will include sampling and laboratory analysis.
• Content: the Art. 21.3 minimum (visible asbestos, state of repair and risk).
• Unit certified: address and reference of the specific flat, commercial unit or industrial unit.
• Date of the visit: the certificate describes the property’s condition on that day.
• Professional’s details: name, qualification and signature, so you can check that their profession is among those accepted.

How much it costs and how long it takes

The law sets no price or deadline, and there is no official fee either. The figures going around are commercial offers.

What most affects cost and time is the size and type of property (a flat is not the same as an industrial unit with a fibre-cement roof), how accessible roofs and courtyards are, whether a laboratory is involved, which adds its own cost and the wait for results, and travel, which some companies charge separately.

If you also need the energy certificate for the same transaction, ask whether both visits can be done at once. And when comparing quotes, look at the scope before the price.

Validity and when to repeat it

Art. 21 sets no validity period or expiry date. It defines the certificate as a reflection of the property’s condition “at the time it is issued”. My recommendation, as a technical criterion and not a legal rule, is to repeat it when what it describes no longer matches reality:

• After work affecting roofs, downpipes, ducts or floors.
• If a material has deteriorated, for example a fibre-cement roof damaged in a storm.
• After a removal, so the certificate reflects absence rather than presence.

If the certificate was issued before building work or a change to the property, check with the notary or the other party whether they expect an updated one.

How we prepare it at Nomadas Architecture

At Nomadas Architecture we are architects, one of the professions the Agència de Residus accepts to sign it while there is no regulation, and we can prepare the certificate of presence or absence of asbestos for your property. If you need it, get in touch and we will go through it with you.

What happens if asbestos is found

Can you still sell or let?

Yes. Art. 21 of Law 8/2026 requires disclosure of the presence or absence of asbestos, and at no point makes the sale or rental conditional on removing it first. A certificate showing presence is just as valid for completing the transaction.

Art. 11 of the same law requires owners to keep the property free of asbestos once it has been identified and to take measures to remove it. The fourth additional provision adds that those obliged must remove asbestos within the deadlines set, on a binding basis, by the competent institutions.

Today these texts contain no general, individual deadline for private owners. 2032 is a European objective, not a binding date for your flat, so the prudent approach is to treat the finding as outstanding work, with a timetable still to be defined.

In practice, the buyer takes on that obligation along with the property. If asbestos is found, it is worth getting a quote for removing and replacing the element before negotiating, so the price is discussed with real figures and not assumptions.

Keep it under monitoring or remove it: how a professional decides

The preamble of Law 8/2026 states that materials must be removed unless this is technically inadvisable, so what the professional assesses is the order and timing of removal.

The INSST methodology we looked at in the inspection section places each material in one of these three outcomes:

• Priority removal: the material’s condition or people’s exposure means it should not wait.
• Active monitoring: the material stays for now, but its condition is checked periodically.
• Preventive maintenance: it is kept in good condition while removal is scheduled.

As an illustration, and not as an official classification, an intact fibre-cement sheet on a roof nobody goes up to usually falls under active monitoring or preventive maintenance, while a cracked downpipe in a courtyard used every day points to priority removal. Priority criteria and removal phases are still pending regulation. If a professional considers that your uralita can wait, they should put it in writing, with the classification applied and how often it needs to be checked.

Removal: RERA-registered company, work plan and documents worth keeping

Removing asbestos from buildings and installations falls squarely under Royal Decree 396/2006 (Art. 3), and its Art. 17 reserves this work for companies registered in the RERA (Register of Companies at Risk from Asbestos). A renovation company without that registration cannot dismantle it, however small the job.

Before starting, the company submits a work plan to the labour authority (Art. 11 of RD 396/2006). The administration has 45 days to respond and, if it does not respond expressly, the plan is deemed approved. Factor that period into your timetable if a sale or renovation is under way.

The Catalan register of qualified companies and professionals is in addition to the RERA, not a replacement for it.

In a renovation of a property built before 2002, the sensible thing is to check for asbestos before signing the building contract, and removal usually appears as a separate item in the quote. Once the work is finished, these are the documents worth keeping:

• Approved work plan: proves the removal was carried out through the legal route.
• Waste management receipts: show the material ended up with an authorised waste manager.
• Post-removal certificate: reflects the property’s new condition and is what the next buyer or tenant will want to see.

Law 8/2026 devotes Art. 26 to grants and subsidies. Your property manager is a good first contact, since they are required to inform the owners’ association about them. Requirements, amounts and how to apply are in our guide to asbestos removal grants in Catalonia.

In industrial units, commercial premises and offices the obligations are the same as in a home, but the scale changes: asbestos tends to be concentrated in the fibre-cement roof, and removing it means replacing it, which weighs on the budget as much as the removal itself. It is also worth checking downpipes, ducts, tanks and insulation.

Price, deposit contract, Land Registry and penalties in the transaction

Effect on price and what to check in the deposit contract

Law 8/2026 says nothing about price. What does happen in practice is that a finding of presence gives the buyer the information to work out how much it will cost to keep that material under monitoring or remove it, and they negotiate with that figure. There are no reliable figures on how much the price drops, and I would be wary of anyone who gives you a fixed percentage. A fibre-cement downpipe in good condition and an extensive, cracked uralita roof are very different scenarios, and the certificate itself is what lets you tell them apart.

The deposit contract (arras) and hidden defects are a matter of civil law, and the asbestos law does not regulate them. My prudent view as an architect:

• Have the contract mention the certificate: date, the professional who signed it and the result, with the document attached as an annex.
• If asbestos is present, set out the split in writing: who takes on removal or monitoring, within what timeframe, and whether either party will apply for removal grants.
• Check the wording with your notary or lawyer, who can assess what the consequences of concealing asbestos would be in your case.

Record in the Land Registry

This is set by the seventh additional provision. When a transfer of the property for consideration (that is, in exchange for payment, such as a sale) is registered, the certificate of presence of asbestos-containing materials must be recorded in the Land Registry, along with whether grants or subsidies under Article 26 have been obtained for its removal.

The provision refers to “the terms established by the regulations on contaminated soil” and does not detail how this will work in practice, although the intention is for declared asbestos to leave a trace in the registry. The next buyer will foreseeably be able to find it when reviewing the property’s registry information, although the law does not spell this out.

What happens if I don’t provide the certificate? Penalties for failing to hand it over

Law 8/2026 classifies failing to hand over the certificate of presence or absence of asbestos in a sale or rental as a minor offence. The penalty for minor offences ranges from €100 to €3,000.

The specific amount will depend on factors such as the risk to health and the quantity and condition of the material.

However, although the obligation to provide the certificate has been in force since 3 October 2026, the specific penalty regime is still awaiting implementing regulations. So the certificate is already mandatory, although enforcement of these penalties depends on that regulation.

Frequently asked questions

Is the asbestos certificate mandatory if I’m letting rather than selling?

Yes. Art. 21.2 requires it “when a property is sold or let”, so the landlord gives it to the tenant just as the seller gives it to the buyer.

Does the certificate expire?

The law sets no validity period: Art. 21 defines it as a reflection of the property’s condition “at the time it is issued”. It is worth repeating if that condition changes, for example after building work.

Can I do it myself with the Agència de Residus model?

No. The model is a template to be filled in by a qualified professional after visiting the property.

Can I already be fined for not providing it?

The obligation has applied since 3 October, but the Art. 54 scale (€100 to €3,000 for minor offences) depends on a decree that has not yet been approved (seventh final provision).

How much does it cost and how long does it take?

The law sets no price or timeframe, and the figures going around are commercial. Ask for a fixed quote and a delivery date in writing before the visit.

Do I have to remove the uralita before selling?

No. The law requires disclosure, not removal. Art. 11 does require owners to act on identified asbestos, within the deadlines set by the competent institutions, so it is worth discussing it with the buyer and reflecting it in the deposit contract.

Does the estate agency or the notary handle it?

No. The obligation lies with the owner or landlord. The property manager ensures and assists (Art. 12.1.b), and the estate agency or notary may ask you for it, but commissioning it is up to you.

Is it required outside Catalonia?

No. Law 8/2026 is a law of the Parliament of Catalonia and only applies to properties located in Catalonia, even though it was also published in the BOE.

If you are going to sell or let, ask for the certificate before publishing the listing, not when the deposit contract is already on the table. If your property was built before 2002, you almost certainly need it; if it is more recent, check with a professional before ruling it out. If you would like us to prepare it for your home, commercial premises or industrial unit, get in touch.

Have you already heard about the certificate in your building or in your own transaction? Tell me in the comments.

The studio was in a kind of industrial shed on the outskirts of Sendai. I remember the endless working hours and an intensity unlike anything I had known before. I also remember the site visits: before going in, we took off our shoes and put on clean overshoes, a small gesture that conveyed an almost ritual respect for the building, even while it was still under construction.

I worked on several projects and competitions, including a housing project in Tokyo for which I travelled to analyse the site: walking around the area, observing the neighbouring buildings, the gaps between them, the distances and all those seemingly minor conditions that could end up becoming part of the project.

The house as an experiment

Living, studying and working in Japan introduced me to a way of making architecture very different from the one I knew in Spain. What struck me most was the freedom with which many architects worked within extremely restrictive conditions. Tiny plots, odd geometries or intense urban density did not necessarily lead to standardised solutions. Very often, they were precisely the starting point for experimentation.

There was also a different relationship with permanence. The city is constantly changing, and the house can be understood as something less permanent, almost as a built trial. I believe that context helps explain the remarkable experimentation in Japanese domestic architecture.

There is also one building I cannot separate from my memories of those years: the Sendai Mediatheque, by Toyo Ito. I went there very often while I lived in the city. Years later, in Hong Kong, I had the chance to attend several of Toyo Ito’s keynote lectures and to return to his work through research and teaching.

Thinking and representing architecture

Over the years, I have come to realise that the influence of that period lies not only in built architecture, but also in the way architecture is thought about and represented.

Representation is never entirely neutral: the way we draw a project also reveals a particular way of understanding architecture. Perhaps that is why I keep returning to Japanese practices that use drawing in radically different ways: the abstraction of SANAA, the almost anthropological density of Atelier Bow-Wow or the atmospheric drawings of Junya Ishigami.

These are architectures I have returned to many times, from different places and with different questions. Of them all, these are probably the ones that have stayed with me the most.

SANAA

SANAA is probably the Japanese reference that has accompanied me the longest. I am still fascinated by how a seemingly simple architecture can conceal enormous spatial complexity, and by how Kazuyo Sejima and Ryue Nishizawa constantly question conventions we usually accept without thinking: where a room begins and ends, whether a route needs to become a corridor, or whether every space must necessarily have a single, unambiguous function. But I am as interested in their architecture as in the way they represent it: seemingly abstract plans, diagrams, models and drawings capable of explaining complex spatial relationships with very few elements. Their work has come up again and again in both my research and my teaching, and it is probably one of the references I have used most to rethink how we explain and design space.

Sou Fujimoto

Sou Fujimoto interests me especially when he pushes domestic conventions to almost extreme situations. Houses where the conventional organisation into rooms disappears, platforms that can alternately be floor, stair or furniture, or boundaries where it is hard to tell exactly what belongs inside and what belongs outside. Some of these proposals may even seem difficult to live in, but that is precisely where I find their interest: they work as built investigations that force us to ask again what a room means, how much space an activity really needs, what we understand by privacy, or where furniture ends and architecture begins. Rather than offering closed answers, his work has the ability to reopen questions that seemed settled.

Atelier Bow-Wow

What has always interested me about Atelier Bow-Wow is the way they observe the city before trying to impose an order on it. There is something almost anthropological about their work: impossible plots, party walls, tiny buildings, stairs, building services, bicycles, neighbours or infrastructure can all become relevant information for a project. Their research on Tokyo and Pet Architecture caught my attention very early on precisely because it gave architectural value to situations that might seem completely banal. Their way of drawing, too, especially those extremely dense sections in which architecture, people, objects and activities all appear at once, has been a recurring reference for me, both as a research tool and when working with students.

Junya Ishigami

What interests me enormously about Junya Ishigami is the way he represents architecture. His drawings have an almost ethereal quality, sometimes seemingly naive, in which structure, vegetation, people and objects appear to carry practically the same weight. But what is fascinating is that this way of representing is not simply a beautiful way of presenting the project: it conveys, with great precision, the atmosphere and spatial relationships that later appear in the built work. The lightness, the absence of hierarchies, the blurred boundaries between architecture and landscape, or that sense that the building almost disappears, are already present in his drawings. It is a particularly interesting example of how representation can stop being a tool for explaining an architecture that has already been conceived and become part of the very process of imagining it.

Jun Igarashi

Jun Igarashi is perhaps the least known architect in this selection, but I find some of his houses especially interesting because of the radical way he works from seemingly very simple conditions. Small houses, elementary structures and the harsh climate of Hokkaido become opportunities to explore the section, wall thicknesses, thermal differences and the relationships between one room and another. What interests me is precisely his ability to produce experimental architecture without the need for grand gestures, showing that the most concrete constraints can often give rise to the most interesting spatial decisions.

An influence that endures

Many years have passed since that time in Sendai, but I keep coming back to these architectures. Not because I intend to transfer a Japanese way of designing literally to Barcelona (the cultural, urban and construction contexts are completely different), but because that period taught me something I still consider fundamental to my work: constraints do not have to lead to predictable answers.

A difficult plot, an existing structure, restrictive regulations or a small home can be precisely the place from which to start asking questions.

And perhaps that is the influence that has endured the most. Japanese architecture taught me to look carefully at what already exists, to question solutions that seem obvious, and to understand drawing and representation not only as a way of explaining a finished project, but as tools for investigating it.

Many years later, those questions still come up when I design, when I do research and when I work with students.

We had a case recently with clients who had already signed a reservation contract (arras) on a house outside Barcelona. After signing, they started to suspect something was wrong and asked us to take a look. During the visit we found serious dampness problems, reinforced concrete beams damaged by water infiltration, and other issues that could mean a major intervention. The problem: the arras were already signed.

The difference between these two kinds of clients usually isn’t money. It’s the moment they called in a professional.

That’s why I want to talk today about what an architect brings before you sign, because that’s when it can actually change your decision. In short: an architect helps you understand what you’re buying, what problems it might have, what you can do with it, what permits you’ll need, and what it will really cost. With all of that on the table, buying stops being an act of faith.

What exactly does an architect do when advising on a purchase?

They analyze the property from a technical and regulatory standpoint, and translate what they find into decisions you can actually make: move forward, negotiate the price, or walk away in time.

It’s not the same as the renovation architect

These are two different phases, and it’s worth not mixing them up. The renovation architect steps in once the home is already yours, and the job is to transform it. Purchase advisory happens earlier, while you can still say no.

I think of it as the difference between a cook and someone who goes with you to the market. You can do a lot with what you buy, but some things can’t be fixed afterward.

It doesn’t replace the real estate agent or the lawyer either

The agent knows the market and local prices. The lawyer reviews liens, contracts, and legal status. The architect deals with something else: the physical condition of the property, what can be built there, and the regulations that govern it.

Three different perspectives. None covers the other two.

What you end up with

It depends on the scope you agree on, but typically you get an assessment of the property’s condition, an analysis of what renovation is feasible, a cost estimate, and a clear warning of the risks you need to weigh before committing.

What the bank and the notary don’t check for you

This is the part that surprises buyers most, so I’ll put it early.

The bank assesses your solvency and appraises the property as collateral for the mortgage. The appraisal calculates a market value; it doesn’t audit the construction condition or the legality of what’s built.

The notary certifies that the transfer is legally valid and checks the property registry status. They don’t visit the home or verify whether the actual layout matches what’s on the deed.

Between what one does and what the other does, there’s a big gap: the real condition of the property, the feasibility of your renovation, and the urban planning legality of what’s built. A qualified professional fills that gap, or nobody does.

The five questions an architect answers before you sign

1. Is what I’m buying in good shape? Structure, dampness, installations, doors and windows. This gets resolved with a technical inspection report on the property, which deserves its own chapter (we cover it in detail in our article on the technical inspection report).
2. Can I do the renovation I have in mind? This is where the most illusions break and the most money gets saved. Is the wall you want to knock down load-bearing? Can the bathroom be moved, or does that depend on the distance to the drain stack? Can the kitchen go against the facade? Can that window be enlarged? The layout you’re dreaming of and the one the building actually allows don’t always match.
3. What permits do I need, and how long will they take? A renovation without a layout change isn’t the same as one that touches the structure or the facade. The type of permit determines the timeline and the budget, and in Barcelona, municipal deadlines can bring plenty of surprises. If you want to go deeper, we explain it in our permit and license management service.
4. What will it really cost? Purchase price, taxes, renovation, and technical surprises all need to be read together. A cheap apartment that needs new installations, drain stacks, and a new roof can end up costing more than a pricier, sound one.
5. Is what’s built actually legal? The uncomfortable question, and the one almost nobody asks.

The part almost nobody checks: urban planning legality

I want to dwell on this one, because it’s where I’ve seen the most expensive headaches, and where people look the least.

When what you see doesn’t match what’s on record

It happens more than you’d think. A terrace closed in twenty years ago, a loft that appeared out of nowhere, a commercial unit converted into housing, square meters that were never declared. The physical reality of a property and what’s recorded in the Land Registry and the Cadastre don’t always line up.

We recently worked on renovating a ground-floor unit of about 80 square meters. On paper it looked like a home with plenty of potential, but when we looked into its history we found that nearly half the surface area came from extensions built over the years. Those extensions were grandfathered in because of their age, but they still carried significant urban planning restrictions: we couldn’t place part of the new functional layout, including the kitchen, in those 40 square meters. The client wanted the kitchen moved there, and legally it simply wasn’t possible. In the end we had to keep it more or less in its original spot and rethink the layout around that constraint.

These discrepancies aren’t just a bureaucratic detail. They can affect financing or a future sale, but also something much more immediate: they can completely change what you’re allowed to do with the home you’re about to buy.

Unlicensed construction: the problem becomes yours

And this is the key part. When you buy a home with work that was carried out without a permit, you become the legal successor (causahabiente) of the previous owner. In practice, you can receive an order to legalize what was built and, if it can’t be legalized, end up facing a demolition order for something you didn’t build.

One important distinction: these are two separate, independent proceedings. The sanctioning proceeding, which imposes the fine, targets whoever commissioned the work. The urban planning legality restoration proceeding, which requires legalizing or demolishing, falls on the property and its current owner. Put simply: you don’t inherit the fine, but you do inherit the problem.

“It’s very old” doesn’t mean “it’s legal”

A common mistake. The fact that enough time has passed that a demolition order is no longer possible doesn’t make the work legal. It’s still unauthorized construction, and that can block you from getting permits later.

I’ve seen owners get denied a permit for something as harmless as a solar panel installation, because part of the home is on record as illegal. Work someone did decades earlier.

Where the architect’s role ends and the lawyer’s begins

We review the consistency between what’s built, the documentation, and the applicable urban planning regulations, and we tell you whether what’s there carries risks and whether your renovation fits the zoning plan. When things move into liens, contracts, or litigation, that’s where a specialized lawyer takes over. Working in parallel is the sensible approach.

When should you call? The purchase timeline

If I had to pick one, it would be before the arras. It’s the last point where you can still negotiate or walk away at no cost. After that, your room to maneuver narrows a lot.

What if you’re buying from outside Spain?

Many of our clients buy in Barcelona without ever having lived here, and they run into vocabulary that doesn’t exist in their home country.

The cèdula d’habitabilitat (habitability certificate), mandatory to sell or rent. The ITE, the mandatory inspection for buildings over 45 years old in Catalonia. Municipal permits with their own timelines. Homeowners’ associations that approve special assessments (derramas) that will affect you even if you just moved in.

None of these have a direct equivalent in the UK, Germany, or the US, so it’s easy to assume things that don’t actually apply, and just as easy to assume something is impossible when it’s actually routine here. Having someone explain it in your own language, with local regulations in hand, avoids costly misunderstandings.

How much does it cost, and is it worth it?

The cost depends on the scope. A one-off accompanied visit isn’t the same as a full technical and urban planning feasibility analysis. It makes sense to agree on this based on what you actually need, so get in touch and we’ll work it out together.

On whether it’s worth it, there’s an argument I find conclusive: the advisory is useful even if you don’t end up buying that particular home. If the analysis saves you from a bad purchase, it’s already paid for itself. And if it confirms the home is a good one, you buy with peace of mind and a realistic renovation plan.

How we support you at Nomadas Architecture

We offer an advisory and support service throughout the buying process, with the same approach we bring to every project: staying close, explaining each step, and not leaving you alone in front of a technical decision.

If the home needs a renovation or rehabilitation, we build on what’s already there and combine it with contemporary intervention.

We work regularly in English and Spanish.

And there’s continuity. From architecture consulting we can move straight into the design project or permit management, without you having to start over explaining your home to a different studio.

Frequently asked questions

Do I have to hire an architect to buy a home?

No. It’s an optional service. What is mandatory is having a qualified professional once the renovation requires a design project and a permit, something a lot of people find out too late.

How is this different from the technical inspection report?

The report focuses on the condition of the property. The advisory service is broader: it includes that analysis but adds renovation feasibility, regulations, permits, and cost estimates across the whole process.

Can you tell me if I can knock down a wall?

Yes, and it’s one of the most common questions we get. You need to check whether it’s load-bearing, how the building’s structure works, and what type of permit the work requires.

Can you come with me to view the apartment?

Yes, that’s part of the accompaniment service. A visit with a trained eye can rule something out in twenty minutes that would otherwise take you months to discover.

Does this apply to new builds or off-plan purchases too?

Yes. For new builds, it helps you review specifications, the finishes report, and customization options before the developer locks in decisions.

What if the apartment has unlicensed construction?

You need to find out whether it can be legalized and at what cost. As the buyer, you can become subject to the legality restoration proceeding, so it’s worth catching this before signing and getting legal advice on it.

Buy with data, not intuition

For almost everyone, buying a home is the biggest financial decision of their life. And it’s still made with less technical analysis than buying a used car.

What an architect brings at this stage comes down to three things:

Certainty about what you’re buying and its condition. Feasibility: what can be done, and with what permits. Real numbers: purchase plus renovation, with no surprises halfway through the work.

One last note before I wrap up. Urban planning regulations are set at the municipal level, and habitability regulations at the regional level. What I’ve described here applies to Barcelona and Catalonia, so check the specifics of each property before assuming anything.

So, when would you call in a professional? Before you start viewing apartments, or once you’ve already got your eye on one? Tell us in the comments. And if you’re in the middle of a purchase in Barcelona, get in touch before signing the arras: that’s the moment we can still really help you.

That’s where this article comes from. A technical home inspection report is the document an architect draws up after thoroughly reviewing a property. It records the property’s actual condition, any defects found, and an objective assessment with photographs. It tells you what you’re really buying, gives you data to negotiate the price, and lets you work out how much the renovation will actually cost before you sign anything.

Today I want to walk you through what that report includes, how it differs from the ITE and from the certificate of habitability (cédula de habitabilidad), because confusing the two can get expensive, who’s qualified to sign it, and why timing matters just as much as the report itself.

What is a technical home inspection report?

A technical inspection report is a document drawn up by a licensed architect or building surveyor (arquitecto técnico) after inspecting a property, reflecting its state of conservation. It records the property’s overall condition, any defects found and their severity, photographs of what was found, and (depending on the type of report) an approximate estimate of repair costs.

But there’s something important to understand: an ITE inspection is fundamentally visual and sensory (organoléptica). No test pits are dug and no finishes are removed unless there are clear signs that justify it. This has caught more than one community of owners off guard when a problem later shows up and they’re told: “but it wasn’t in the ITE.” And that’s true, it wasn’t. An ITE can’t guarantee with 100% certainty that no hidden defect exists.

This happened to us, for example, when we started renovating a ground-floor unit. When we lifted the flooring, we found that the building’s original sewer line (the pipe that collects wastewater and carries it to the main sewer) was completely deteriorated. It had been leaking for decades, washing away the soil aggregate to the point of undermining part of the building’s foundation. It was clearly a shared, building-wide issue, yet it was impossible to detect during an ITE because it was completely hidden beneath the flooring.

What a technical report is not

The concepts get mixed up a lot here, so let’s go through them one by one:

It’s not a valuation. A valuation calculates the property’s market value, usually so the bank will approve the mortgage. It won’t tell you whether there’s a worrying crack in a load-bearing wall.

It’s not an energy performance certificate. That evaluates energy consumption and gives you a rating from A to G. It’s mandatory for selling or renting, but it doesn’t assess the building’s structural condition.

It’s not the ITE. And this one deserves its own section, because it’s the most common mix-up and the one that causes the most trouble.

Differences between the technical home inspection report, the ITE, the certificate of habitability, and the expert report

Four documents, four different purposes. Here’s a quick summary before going into detail:

The ITE belongs to the building, not to your flat

The ITE (Inspección Técnica de Edificios, Technical Building Inspection) is mandatory in Catalonia for residential buildings once they turn 45 years old, under Decree 67/2015, and it’s repeated every 10 years. It’s carried out by a qualified technician, who draws up the report and files it with the Agència de l’Habitatge de Catalunya (Catalan Housing Agency) to obtain the certificate of fitness. Notaries request it for the sale of properties of that age.

Watch out for this: the obligation kicks in automatically once the building turns 45, no notification letter is required.

The certificate of habitability confirms the home is fit to live in

It certifies that the home meets the minimum requirements for surface area, sanitation, and facilities. It’s mandatory for selling and renting, under Law 18/2007 on the right to housing in Catalonia. It certifies legal minimums, not quality or state of conservation.

The expert report is for making a claim

It’s drawn up once there’s already a dispute and evidence is needed with legal standing for court proceedings. By definition, it comes too late.

The pre-purchase inspection report is the only one designed for you

It’s voluntary, you commission it yourself as the buyer, and it looks at the specific property you’re interested in. It’s the only one of the four that exists to protect you before you sign.

What’s the point of getting a report before buying?

To make the decision with facts in hand instead of a hunch. In practice, it gives you four things.

• Knowing what you’re really buying. According to Tinsa, one in four homes in Spain has a serious problem that isn’t visible to the naked eye, with an average repair cost of around €10,000. It’s not bad luck, some things simply aren’t visible during a viewing.
• Negotiating with arguments. A report documenting an outdated electrical installation or rising damp is a negotiating position, not a complaint. It completely changes the conversation with the seller.
• Working out the renovation cost before signing. This is what I value most. Knowing whether the renovation you have in mind will cost €40,000 or €90,000 changes whether that purchase makes sense for you or not.
• Being able to walk away in time. Sometimes the report says no. And that “no,” caught in time, is the best money you’ll spend in the whole process.

Why timing matters: better to know before you sign

My recommendation is to get the inspection done before signing the deposit agreement (arras). Not because you necessarily lose all legal protection after buying, but because before signing, you still have the power to decide.

In Catalonia, the Civil Code addresses these situations through what’s known as “lack of conformity” (falta de conformidad). Currently, the seller is liable for any lack of conformity that already existed at the time of delivery and that becomes apparent within the following three years. What’s more, if it appears within the first two years, in certain cases it’s presumed to have already existed when the property was handed over.

But having the right to make a claim is one thing, and having to actually do it is quite another. If you spot a defect before buying, you can assess how much it costs to repair, negotiate the price, ask for it to be fixed before the purchase, or simply decide the property isn’t for you. If you discover it afterward, the problem is now yours, and even if you can make a claim, you’ll likely need technical reports, negotiation, and, in some cases, lawyers.

That’s why a pre-purchase inspection makes so much sense to me: an architect helps you understand what you’re buying while you’re still in time to decide whether you want to buy it at all.

If the building’s ITE is in order, is everything fine?

Not necessarily, and this belief is one of the costliest ones out there.

The ITE is a visual inspection of the building’s common elements: structure, façades, roofs, and shared installations. Its purpose is to assess their state of conservation and fulfil the maintenance obligation, not to carry out an exhaustive audit of every single home.

And there’s an important limit here: the inspection is visual. No test pits are dug and no false ceilings or flooring are removed unless there are signs that justify it. So a favorable ITE doesn’t necessarily mean there are no hidden defects.

This happened to us while renovating a beautiful flat in a historic building in Barcelona whose ITE was favorable. The home had false ceilings, and when we started the work and took them down, we found that the wet areas (kitchen and bathrooms) had been suffering leaks from the flat above for a long time, and several steel beams were affected. It was a fixable problem, but the structure had to be reinforced during the work, and the client later had to claim the cost back from the community of owners.

So a favorable ITE is useful information, but it’s not an absolute guarantee about the condition of your home. A building can have a valid certificate of fitness while your flat has problems that simply weren’t visible when the inspection took place.

What does a home inspection actually check?

The scope varies by professional, but a thorough inspection covers these areas:

• Structure and foundations: cracks, fissures, tilting, settlement, condition of floor slabs and joists.
• Roof and façade: leaks, sealing, condition of the cladding.
• Damp: source, extent, and possible treatment. Rising damp, condensation, and water infiltration aren’t fixed the same way, and they don’t cost the same either.
• Installations: electricity, plumbing, drainage, climate control, and whether they meet current regulations.
• Joinery and insulation: thermal bridges, windows, thermal and acoustic comfort.
• Planning legality and documentation: making sure what’s actually built matches what’s on record, so you don’t inherit someone else’s violation.

In Barcelona, there are also some very local issues to watch for. In Eixample buildings, we tend to look closely at lightwells, the condition of wooden or steel joists, and previous renovations done without a permit, which are exactly the ones that complicate any future work later on. And they turn up more often than you’d think!

Who can carry out a technical home inspection report?

A licensed architect or building surveyor (arquitecto técnico). This isn’t a formality: their qualification is what allows them to interpret a structural defect, tell a harmless crack apart from an active one, and sign a document with real professional backing.

There’s a second condition that matters just as much as the first: independence. Independent from whoever is selling you the flat, and also from whoever is going to carry out the work. If the same person assessing the condition is also the one billing for the repair, there’s an obvious conflict of interest.

How much does it cost and how long does it take?

Every property is different, and so is the type of review it needs. Visiting a renovated flat in a relatively recent building isn’t the same as visiting a home in a historic building, a single-family house, or a property with extensions and possible planning discrepancies.

That’s why, before carrying out an inspection, we assess the type of property, its size, its age, and the documentation available, to work out what needs reviewing and how broad the report should be.

Either way, the important thing is to do it before you commit to the purchase, leaving enough time to review what we find and, if necessary, request additional documentation or carry out further checks before signing.

How we approach this at Nomadas Architecture

At Nomadas Architecture, we’ve carried out many home renovations, and that changes the way you look at a flat. When you’ve spent years opening up walls in old Barcelona buildings, you know where problems tend to hide and what’s worth keeping from what’s already there.

We work with foreign clients who are buying here without knowing the local regulations or the language, so we walk through the report with them in both English and Spanish, explaining the practical implications of each finding. A report you don’t understand is no use to you.

And there’s something buyers renovating especially value: we can move straight from the report into the project. We already know what we found, what it costs to fix, and what’s worth preserving from what’s already there, which is exactly the part we enjoy most.

Frequently asked questions

Is a technical report mandatory to buy a home?

No. A pre-purchase inspection is voluntary. What’s mandatory in Catalonia is the ITE for buildings over 45 years old and the certificate of habitability to sell or rent.

How is it different from a valuation?

A valuation calculates market value, almost always for the mortgage. A technical report assesses the property’s real structural condition. You can have a high valuation and a home with serious defects.

When should I request it, before or after signing the deposit agreement?

Before signing the deposit agreement (arras). Afterward, you’ve already committed money, and your ability to negotiate or walk away is much more limited.

Does it apply if I’m buying new-build property?

Yes. For new-build homes, it lets you document construction defects and claim them within the warranty periods set out in Spain’s Building Standards Act (Ley de Ordenación de la Edificación).

Can I use the report to negotiate the price?

Yes, and it’s one of its main uses. A documented defect with an estimated repair cost is an objective argument for asking for a discount or compensation.

Is it valid for a claim if the defect appears after I buy?

It helps, but it doesn’t replace an expert report.

Before you sign, look under the paint

The idea I’d like you to take away is simple: buying a flat in Barcelona is the biggest financial decision most people will ever make, and it’s still often made with less technical information than buying a used car.

There’s no trick and no magic formula here, just a professional looking with a trained eye at what you can’t see during a viewing.

The four documents, one line each:

• Inspection report: voluntary, your home, for deciding and negotiating.
• ITE: mandatory at 45 years, the building’s, visual.
• Certificate of habitability: minimum legal requirements to sell or rent.
• Expert report: for making a claim once there’s already a dispute.

A couple of final caveats. The market figures cited here (average repair cost, inspection prices) come from industry sources and vary a lot case by case, so treat them as an order of magnitude, not a quote. And ITE regulations are set at the regional level: what’s described here applies to Catalonia, timelines differ in other regions.

So, has buying or renovating a flat ever caught you by surprise, one of those things you only discover once you open up the first wall? Tell us about it in the comments, we love learning from these stories! And if you’re in the middle of a purchase in Barcelona and want to know what you’re getting into before you sign, get in touch and we’ll take a look with you.

Years later that image lines up with a figure that’s gone viral: Tokyo, a single city, builds as much housing in a year as the whole of Spain, sometimes more. It sounds like an exaggerated headline, but the numbers hold up. I want to walk through why Japan builds more housing than Spain, what’s actually true in that comparison, and which lesson genuinely applies in Barcelona (and which one we’re better off leaving alone).

My conclusion, up front: Japan builds more because it decided, by law, to make building easy. Spain builds little because it decided the opposite. But the Japanese model has a flip side that rarely makes the headlines, and it changes the moral of the story quite a bit.

Does Tokyo really build more housing than Spain? The numbers

Yes, it’s true, with one important caveat worth keeping in mind before you repeat the headline.

How much Tokyo builds in a year

Tokyo approved around 145,000 new homes in 2018, with a population of 13.5 million (Xataka, drawing on the Financial Times). In some years that beats what California builds (three times the population) or England (four times). The striking part: nearly all of those homes went up inside existing neighbourhoods, not on greenfield land.

This wasn’t a one-off spike. Tokyo has tripled its housing stock in fifty years and has kept adding to it at close to 2% a year since 2000, even after its population stopped growing.

How much Spain builds

Spain completed 100,980 homes in 2024, its best figure in twelve years, according to the Observatorio de Vivienda y Suelo (the Housing Ministry’s housing and land observatory). That same year it started 136,187, the most in fourteen years. The trend carried into 2025: the fourth quarter was the strongest fourth quarter for home construction in seventeen years.

The recent figures sharpen the headline. Over the past decade Spain built somewhere between 40,000 and 90,000 homes a year, and against that Tokyo ran away with it. In raw numbers, the gap has now narrowed.

The fair comparison is per capita

This is where the argument becomes hard to dispute. Instead of comparing a city with an entire country, look at the ratio per head of population:

• Tokyo: about 10.7 homes per 1,000 residents (2018).
• Spain: about 2.1 per 1,000 residents (2024, its best recent year).

Tokyo builds roughly five times more housing per resident than Spain, and that’s measuring Spain at its strongest in over a decade. Five times over. The scale of the contrast is real, even if comparing a city with a country always limps a little.

Why Japan builds so much: four things we don’t have here

The underlying reason is single and simple: in Japan, building housing is easy by legal design. It comes down to four mechanisms.

Land is regulated by national law, not town by town

In Japan the rules on land use are set by the central government, not by each town hall. That strips a lot of blocking power from local interests, the kind that stall developments for years elsewhere. National authority overrides “not in my backyard.”

In Spain it’s the reverse. Planning sits with the regions and the municipalities, and any permit can turn into a long negotiation.

Zoning that adds uses instead of banning them

The Japanese system has 12 zone types (13 since 2018), far fewer than the average Spanish or American city. And they work in an unusual way. Instead of saying “housing only here,” they set the maximum level of nuisance allowed in each zone.

The practical effect is huge. You can build housing almost anywhere, because 11 of the 12 zones allow it. A factory can’t move into a residential neighbourhood, but a home can go into a light-industrial zone. And residential means residential, with no distinction between a rental flat, a detached house, or an apartment block. That flexibility multiplies the land available for housing (Mutuactivos).

Permits by right: meet the rules and you get it

In Japan permits work “by right.” If your project meets the technical and regulatory requirements, the authorities are obliged to approve it. There’s no discretionary stage where the project gets tangled up in political or neighbour pressure (El Imparcial).

Less uncertainty for the builder means more building. Easy to grasp, hard to copy.

The house that loses value (and why that unlocks construction)

This one is the most cultural, and the most interesting. In Japan a timber home loses almost all its book value in about 20 to 30 years. After that, the bank values the property as if only the land existed. The scrap and build mentality dominates, inherited from the postwar years and reinforced by earthquake-safety rules.

This is the link almost nobody makes: if your house doesn’t gain value, you have no reason to block the development next door “to protect your investment.” Take away that brake, and housing flows.

The four differences with Spain, in short:

• Land regulation: national in Japan, regional and municipal here.
• Zoning: inclusive (adds uses) there, exclusive (separates uses) here.
• Permits: by right there, with room for discretion here.
• Home value: depreciates there, appreciates here.

The flip side the viral headlines leave out: 9 million empty homes

Look closer, though, and the model has an uncomfortable underside. Japan sits on some 9 million empty homes, close to 14% of its stock, the so-called akiya (idealista). The same machine that produces cheap housing in Tokyo leaves entire villages abandoned.

What akiya are

Akiya (空き家) literally means “empty house.” These are homes left unoccupied for more than a year, many of them inherited and never sold, concentrated in the rural Japan hit hardest by ageing and population decline. Some towns give them away in exchange for renovating them.

Building a lot has a price

A depreciating house unlocks construction, yes, but it also means housing barely builds any wealth. In Spain your flat is a big chunk of your lifetime savings. In Japan, for many families, it’s a good that gets used up and thrown away. Add the environmental cost of demolishing and rebuilding every few decades, and the balance sheet looks less tidy.

Why the Japanese model can’t be copied wholesale in Spain

A few deep reasons. Our culture treats housing as an investment and an inheritance, not a perishable good. Planning is in the hands of the regions and municipalities, not the central government. And the demographics run the other way: Spain’s population is growing, Japan’s has been falling for more than fifteen years, so across much of the country there’s land to spare.

Copying the whole Japanese system wouldn’t fix Spain’s problem. But a few individual pieces would be worth having.

Barcelona, the city where you can barely build new housing

In 2025 the city’s quarterly average of new-build permits hovered around 300 homes, less than half the 2022 figure (Ajuntament de Barcelona). There’s almost no free land left to build on.

What I would take from Tokyo

Speed. Not the demolition culture, but the idea that a clear, predictable permit unblocks supply. In a city like Barcelona, where paperwork can drag on forever, learning from that Japanese predictability would make complete sense.

What I wouldn’t import: demolishing instead of renovating

When you can’t grow outward, you grow inward. Here we call it a remonta: adding a floor on top of an existing building, a common move in the Eixample. Reusing the building that’s already standing instead of knocking it down is the exact opposite of Japan’s scrap and build. And in a city with Barcelona’s heritage, it’s also the sensible thing to do.

At Nomadas Architecture we work along exactly those lines: bringing out the value in what’s already there, the historic parts of a building, and pairing it with contemporary work. We don’t think building fast and building a lot is the only answer. In an urban fabric this dense and this full of memory, renovating well usually beats tearing down. Residential renovation is in fact one of the fastest-growing segments in Spain right now, with refurbishment permits at record highs.

Frequently asked questions

How many homes does Tokyo build a year?

Around 145,000 in 2018, with a population of 13.5 million. It’s the most cited reference figure and works out to about 10.7 homes per 1,000 residents.

Does Japan build more housing than Spain per capita?

Yes. Tokyo builds about five times more housing per resident than Spain, even when you compare it against 2024, Spain’s best year in over a decade.

Why don’t housing prices in Tokyo climb the way they do in Barcelona or Madrid?

Because supply grows at the pace of demand. When you build enough, prices don’t shoot up. In cities where supply is blocked, the opposite happens.

Why are so many houses demolished in Japan?

Because homes depreciate to almost nothing in 20 to 30 years, and the demolish-and-rebuild mindset dominates, reinforced by earthquake regulations.

Could Spain apply the Japanese housing model?

Only in part. Faster permits would help, but the disposable-housing culture clashes with how we understand property and inheritance, and with demographics that, unlike Japan’s, keep growing.

So: build or preserve?

Japan doesn’t build more by magic. It builds more because decades ago it chose to make building easy, and that’s the idea that really counts: this is a political decision, not a cultural mystery. Like any decision, it comes with fine print.

The main threads, one line each:

• National regulation: less local veto, more housing.
• Inclusive zoning: housing fits almost anywhere.
• Permits by right: meet the rules, you build.
• Depreciating homes: unlocks supply, but builds no wealth and multiplies the akiya.

The most cited Tokyo figures are from 2018 and the Spanish ones move every year, so it’s worth checking the current number before taking it as gospel. And be careful with the city-versus-country comparison. It’s powerful, but imperfect. The number that holds up is the one per resident.

My view, after living there and renovating here: we don’t need to copy Japan, we need its speed without its throwaway culture. Barcelona doesn’t get fixed by demolishing. It gets fixed by making it easier to renovate and bring back to life what’s already standing.

How do you see it? Would you rather have a city that builds nonstop or one that looks after and reuses what it already has? Tell us in the comments. And if you’re mulling over renovating your home in Barcelona, get in touch.

What I can give you are concrete ranges, with examples and the time each phase really takes, from the moment you decide to renovate until you move in. That’s what almost no article explains in detail: a renovation isn’t just weeks of building work, it’s a full process with design, permits, and execution that in Barcelona usually takes considerably longer than people expect.

In numbers: a full renovation in Barcelona runs between €500 and €2,000 per square metre depending on quality, and the whole process, from decision to keys, takes somewhere between 6 and 12 months. Let’s break it down.

Full renovation price in Barcelona per m² by quality level

Price per square metre is the quickest reference for comparing quotes, but it only makes sense if you know which quality level you’re comparing. Here are the four levels common in the Barcelona market.

Basic renovation

Between €500 and €800/m². Standard materials, no significant layout changes, and renewed installations but no extras. This is the typical bracket for rental flats or first homes on a tight budget.

Budget renovation

Between €700 and €1,200/m². This brings in better-quality materials, the odd layout change, and full kitchens and bathrooms with careful finishes. It’s the most common bracket for a family’s main home.

Mid-range renovation

Between €1,000 and €1,500/m². Full reconfiguration, high-end materials, bespoke joinery, and often home automation or ducted air conditioning. The degree of customisation rises sharply.

High-end renovation

From €1,500/m² upwards, with no real ceiling. Here the budget stops being the priority and what rules is exclusivity: restoration of original features, bespoke interior design piece by piece, full home automation.

Renovation cost by room, if you’re not doing a full renovation

Not everyone needs to gut the whole place. If you’re renovating in parts, these are the rough ranges per room, at basic and full quality:

• Kitchen (10-15 m²): between €8,000 and €12,000 for the basic version, up to €15,000-30,000 for a full renovation with high-end appliances.
• Full bathroom (5-8 m²): between €4,000 and €7,000 basic, up to €8,000-18,000 for the full version.
• Living and dining room: between €3,000 and €6,000 basic, up to €8,000-20,000 if it includes bespoke joinery.
• Bedroom: between €2,000 and €4,000 basic, up to €5,000-12,000 with bespoke fitted wardrobes.
• Full electrical installation: between €4,000 and €7,000, up to €8,000-14,000 with home automation.
• Full plumbing: between €3,500 and €6,000, up to €7,000-12,000 for more complex installations.

What makes the price go up or down

The building’s starting condition

An Eixample building with high ceilings and Catalan vaulted ceilings isn’t renovated the same way as an eighties block or a ground-floor unit in a 19th-century building. Fixing damp, cracks, or very old installations sends the budget up before you even reach the “pretty” part of the renovation.

Layout changes and structural elements

Knocking down a partition wall is cheap. Knocking down a load-bearing wall is not: it requires an architect’s study, reinforcing beams, and specific permits. Changing the layout can raise the budget by 15% to 25%.

Quality of materials and finishes

This is the most variable factor of all. Going from standard laminate flooring to natural wood parquet, or from off-the-shelf furniture to custom-built pieces, can raise the final budget by 15% to 30%.

Access: lift, old town, building height

Carrying materials up to a fourth floor with no lift in Ciutat Vella costs more than unloading straight onto the ground floor. It’s a factor almost nobody budgets for at the start and that shows up anyway.

Permits and municipal fees

Every building project in Barcelona goes through the City Council. A works notification (comunicado de obras) for a simple renovation costs little, but a renovation involving structural changes usually needs a major works licence, with different timelines and fees.

The factor almost no article mentions: listed buildings and protected features

Many buildings in the Eixample, Vila de Gràcia, or Ciutat Vella have features listed by the City Council: modernista façades, original staircases, moulded ceilings, hydraulic tile floors. Renovating a flat inside a building like that isn’t the same as renovating an unprotected block.

So what changes exactly? The technical project needs more documentation, sometimes you need heritage sign-off before touching certain features, and licence timelines stretch out. There’s no single figure that works for every listed building; each one has its own level of protection, so I’m not going to give you a generic range that sounds good and helps with nothing. What I can tell you is that, if your building has protected features, you’ll want to factor that in from day one, not discover it halfway through the work.

How long a full renovation in Barcelona takes: the complete timeline

This is what really separates planning well from getting a nasty surprise. The renovation doesn’t start the day the workers arrive, it starts long before.

Design and project phase

Between 8 and 12 weeks. This is where the spatial layout is defined, materials, details, and finishes are chosen, and all the technical documentation needed to apply for the licence is prepared.

Licensing phase

Variable, and the phase you can control least. A works notification can be cleared in days; a major works licence, usually needed for renovations with structural changes, can take several months.

Building phase

Between 3 and 5 months for a 70-100 m² flat with a full renovation. More basic renovations, with no layout changes, can be done in 6-8 weeks.

Total time: from decision to moving in

Counting design, permits, and building, the usual span for a full renovation in Barcelona is 10 to 12 months. Yes, it’s more than most people reckon at the start.

Why renovating without a technical project costs more and takes longer

I know what you’re thinking: if I skip the design phase, I save time and money. It’s exactly the opposite.

Without a project, improvised decisions tend to crop up mid-build: a missing socket, a layout that doesn’t work as imagined, materials that don’t arrive on time because nobody ordered them in advance. Every one of those surprises halts the work, and every stoppage costs money.

At Nomadas Architecture we always tell our clients the same thing: the project isn’t an expense, it’s the tool that keeps the budget from blowing up halfway through.

Steps to renovate your home in Barcelona, from start to finish

1. Technical visit and initial diagnosis, to establish the property’s real condition before quoting anything.
2. Interior design and layout project, where you define how each space will turn out.
3. Detailed quote broken down by item, not a single lump sum.
4. Municipal licence application, according to the type of work involved.
5. Carrying out the work, with regular progress reviews.
6. Handover, where finishes are checked and the certificate that triggers the statutory guarantees is signed.

How to save on your renovation without losing quality

• Define the project properly before starting. Every change of mind mid-build costs more than deciding it at the outset.
• Prioritise installations and structure over showy finishes. Good electrics and plumbing are invisible, but they’re what prevents the most problems in the long run.
• Ask for quotes broken down by item, not a closed figure with no explanation. That way you can decide where to trim without surprises.
• Set aside a 10% margin on the initial budget for contingencies, especially in older buildings.

Your renovation’s legal guarantees: what the law covers

The Building Regulation Act (Ley de Ordenación de la Edificación, LOE) sets three guarantee periods: 1 year for finish defects, 3 years for faults affecting habitability (installations, damp, insulation), and 10 years for damage affecting structural safety.

That said, the mandatory ten-year insurance only applies to new builds, not renovations. In a renovation, those LOE periods apply when the work affects structure, habitability, or finishes, but the real protection depends on your contract with the firm and on having a signed handover certificate, not on any mandatory insurance. That’s why you should always insist on a written contract with clear guarantee clauses.

Frequently asked questions about the price and duration of a renovation in Barcelona

Do I need a municipal licence to renovate my home?

It depends on the scope. Finish changes usually don’t need one, but if you touch the layout, the structure, or the façade, Barcelona City Council usually requires a works notification or a major works licence.

Can I live at home during the work?

For partial renovations, sometimes yes. For a full renovation, it’s usually neither feasible nor advisable, especially if the installations across the whole home are being touched. We definitely don’t recommend it in any case.

Is it better to renovate before or after buying the furniture?

Before, always. The interior design project should define the spaces and exact measurements so the furniture fits, not the other way round.

What guarantees should I demand from the firm I hire?

A written contract, an itemised quote, and a signed handover certificate on completion, because that’s what triggers the LOE periods.

How long does just the building part take, without design or permits?

Between 6 weeks for a basic renovation and 5 months for a full renovation in a medium-sized flat.

Renovating your home in Barcelona?

If there’s one thing we’ve learned at Nomadas after so many renovation projects across the city, it’s that budget and timelines depend far more on the building’s starting point than most people imagine. That’s always where we begin: understanding the building before talking numbers.

Have you ever renovated a flat in Barcelona? Tell us how long your process actually took.

In Catalonia, asbestos was used in construction right up until 2002, so any renovation of a building from before then runs into it sooner or later. It’s not just a cosmetic problem: handled badly, it releases fibres that are dangerous to anyone living or working in the building, which is why removing it is never an optional extra.

The good news: since 2019 the Generalitat has been funding its removal, with grants that can cover 100% of the cost. The less good news: the 2026 call has already closed, 2 July at 2 p.m. If you’ve landed here looking to apply right now, I’ll be straight with you: this round is no longer open. But keep reading, because the rest of this guide, requirements, amounts, documentation, and what to do while you wait for the next call, is still exactly what you need.

Current status of the asbestos call in Catalonia

The 2026 call was approved through Resolution TER/1743/2026 of 28 May (DOGC no. 9687), based on the regulatory framework of Resolution TER/1547/2026 of 18 May (DOGC no. 9670). The application window was open from 18 June at 9 a.m. to 2 July 2026 at 2 p.m., managed by the Catalan Waste Agency (Agència de Residus de Catalunya, ARC). You can review the full procedure on Gencat to see the complete history.

As of today, it’s closed. For now there’s no official date for the next call. If anyone gives you one, be sceptical: not even the Generalitat itself has published it yet.

What we do know is that this has repeated almost every year since 2019, so it will come back. And when it does, whoever has their paperwork ready in advance gets there ahead of whoever starts hunting for it on the day.

When will the next call open?

I’m not going to invent a date here. Nobody has one yet. But the track record does tell us something interesting.

How the timetable has varied in previous calls

The length of the window varies enormously from one year to the next, something very few articles on the subject explain properly:

Did you know the 2026 call was open for just 15 days, against the 10-plus months of the 2025 one? That gives you a sense of how unpredictable the timetable is, and of why preparing your documentation in advance matters as much as it seems to.

In the meantime: prepare your documentation, don’t wait for the opening

These grants are awarded in order of application, not by lottery or scoring. It’s what’s known as non-competitive public concurrence: the first correct applications to come in are the first to get paid, until the allocated budget runs out. Someone who turns up on day 3 with half their paperwork done has probably already missed out, even if they’re fully entitled to the grant.

At Nomadas we work this way with our clients: if we know there’s an asbestos-cement roof in the project, we get the technical report and the rest of the documentation ready well before the call is announced. On opening day, all that’s left is to submit.

There are two separate grant lines: don’t mix them up

Something almost no article on this topic clears up: there are two different calls for asbestos in Catalonia. Here they are:

General asbestos-removal line

This is the one we’ve described so far: any owner of any property containing asbestos can apply within the window the ARC sets each year.

Specific line for damage from exceptional weather events

There’s a second line, smaller and more occasional, for asbestos-cement roofs damaged by hailstorms or storms officially declared by the Catalan Meteorological Service (Servei Meteorològic de Catalunya). The 2026 one (Resolution TER/188/2026) opened on 20 January for damage in the Ripollès, the Garrotxa, and l’Alt Urgell, with a one-month window.

If your roof was broken by a specific storm, don’t wait for the general call: this line is activated as weather events are declared, and it tends to move faster.

How much does the grant cover?

The amount depends on the square metres of asbestos to be removed, capped at €30,000 per property:

For non-roof elements (tanks, downpipes, gutters), the ARC provides an official spreadsheet to convert linear metres or volume into equivalent square metres.

What the grant covers and what it doesn’t

The 2026 call had one particular feature compared with previous years: it covered any type of asbestos waste, not just roofs. Specifically:

• Dismantling and removal of the asbestos element (roof, downpipe, tank, gutter, façade).
• Transport of the waste to an authorised waste manager.
• Treatment of the waste at approved facilities.

What it never covers:

• The new materials that replace the removed asbestos (the tiles, the sandwich panel, or the new roof are on you).
• VAT, where the beneficiary can deduct it.

Who can apply for the grant?

Any owner of a property containing asbestos in Catalonia can apply, whether:

• An individual, using a digital certificate or idCat Mòbil.
• A residents’ association, with prior agreement from the owners’ meeting.
• A company or self-employed person, owning an industrial unit, business premises, or home containing asbestos.
• A public body, applying through EACAT.

Requirements to qualify for the grant

• The removal must be carried out by a company registered with RERA (the Register of Companies with Asbestos Risk). Not just any builder will do: it has to be listed in that specific register.
• The application must be submitted before the work begins. The cost is only eligible from the application date onwards, never before.
• You must be up to date with your tax obligations to the Generalitat and to Social Security.

Documentation you need to apply

This is the part that makes the difference between submitting on day 1 and being shut out by a last-minute request for corrections. The documents the ARC asks for are:

• Descriptive report, with the property details, the asbestos elements, and the RERA company that will do the work.
• Annex 1, with the screen capture from the ICGC’s VISSIR viewer and the surface area in square metres (only if there’s a roof; for other elements, the location is enough).
• Annex 2, with general and close-up photographs of the element to be removed. If the roof is double-layered, photos of both the front and the back are required.
• Proof of ownership of the property: the title deed, a land registry extract (nota simple), or a certificate of ownership and encumbrances.
• The owners’ meeting agreement, if the applicant is a residents’ association.
• And, of course, the quote from the RERA company, with the square metres broken down consistently with the report and the annexes.

How to apply for the grant, step by step

1. Request a quote from a RERA-registered company, with the report and annexes filled in as far as possible.
2. Check that the square metres match across the report, Annex 1, and the quote. This is the most common error and the one that generates the most requests for corrections.
3. Submit the application on opening day itself, identifying yourself with a digital certificate, idCat Mòbil, or the appropriate system if you’re a legal entity.
4. Wait for the decision. The ARC usually decides within a window of a few weeks to several months; in previous calls the list of beneficiaries has been published around 3–6 months after the window closed, though this isn’t a fixed timeframe.
5. Carry out the removal once you have a favourable decision, always with the RERA company named in the application.
6. Justify the expense with the final invoice to receive payment.

Is it compatible with other renovation grants?

Yes, and this is something many owners write off without checking. This grant is compatible with other public or private aid, such as full-renovation schemes or energy-efficiency funds, as long as the combined total doesn’t exceed the actual cost of the work.

But look closer and there’s an important caveat: it’s subject to the de minimis regime (Regulation (EU) 2023/2831), which limits the total public aid that any one person or company can receive over a given period.

This has a direct implication if you’re planning a full renovation: asbestos removal and the rest of the work can go hand in hand, but it’s worth reviewing the de minimis ceilings before stacking several aid lines at once.

Frequently asked questions about asbestos grants in Catalonia

Can I file the application on behalf of my parents, if they’re elderly and don’t have a digital certificate?

Yes, but you’ll need power of attorney. This can be a notarial power of attorney or, more conveniently, an “apud acta” representation through Representa.cat, where your parents verify their identity by video or in person, without needing their own idCat or digital certificate.

What happens if my application doesn’t get in on time, or the budget runs out?

You lose that call. There’s no waiting list or second chance within the same year: you’ll have to prepare your documentation and wait for the next one.

Can I remove the asbestos without waiting for a grant?

Yes, and in many cases it’s the sensible option if the roof is deteriorating or the renovation project can’t wait months. The removal must always be done by a RERA company, grant or no grant.

Does the decision take the same time every year?

There’s no fixed timeframe in law. Recent calls have been decided within a range of 3 to 6 months, but that’s a rough guide, not a guarantee.

Don’t want to wait for the next call? Remove the asbestos now

If you’re weighing up the renovation or refurbishment of a masia (traditional Catalan farmhouse), an industrial unit, or a 1960s or 1970s building in Catalonia, asbestos is almost certainly part of the equation, and removing it shapes your timeline, your budget, and, with a bit of luck, the grant too.

At Nomadas Architecture we run into this on a large share of the renovation projects that touch old roofs, so we factor it in from the very first site visit: we identify whether there’s asbestos, calculate the surface area, and get the documentation ready for when the next call opens, or handle the removal anyway if the window is closed.

Have you ever come across an asbestos or uralita (asbestos-cement) roof when buying or renovating a home?

Official sources consulted

• Official grant procedure on Gencat
• The Catalan Waste Agency’s asbestos grants page
• Resolution TER/1547/2026 of 18 May (DOGC no. 9670, 21/05/2026) and Resolution TER/1743/2026 of 28 May (DOGC no. 9687, 16/06/2026)

Today I want to bring up exactly that: the change of use from commercial space to dwelling, one of the processes you ask us about most often at the studio. The idea is tempting —buy cheaper, live or invest in a central area, design a loft to your taste, but the path has very specific rules. And skipping them is expensive.

Let me be blunt: not every commercial ground floor in Barcelona can become a home. Whether it’s feasible depends on planning regulations, on the physical condition of the space and on the homeowners’ association. Before signing anything or knocking down a single wall, you have to check.

In this guide I’ll walk you through, step by step, the requirements to convert a commercial space into a home or loft in Barcelona: what the regulations say, what the space must comply with, what procedures await you, and which mistakes block the most projects. Let’s get into it.

What it means to convert a commercial ground floor into a home in Barcelona

Converting a commercial space into a home is not just a renovation. It is a change of use: an administrative procedure by which a property that was authorised for commercial use becomes authorised for residential use.

That difference is key. You can renovate a commercial space inside as much as you like, but until Barcelona’s City Council officially authorises the change of use and the Generalitat issues the habitability certificate (cèdula d’habitabilitat), that space is not legally a home. You can’t sell it as a flat, or rent it out as a dwelling.

That’s why this process combines two worlds: the planning side (does the city allow people to live there?) and the technical habitability side (does the space meet the conditions to be lived in with dignity?). Both have to say yes.

Differences between loft, primary residence and studio under Catalan regulations

Here it’s worth clearing up something that causes a lot of confusion: “loft” is not a legal category. Catalan regulations have no “loft use”. It’s a commercial and design term that describes an open-plan space, with few partitions and, often, high ceilings.

What the law recognises is the concept of dwelling, and every dwelling, whether you call it a loft, a studio or a flat, must meet the same habitability framework. The difference is one of layout and floor area, not legal category.

The conclusion is simple: if you want a loft, what you’re really asking for is a dwelling with an open layout. The procedure and the requirements are those of any home.

Why more and more owners are betting on this conversion

The underlying reason is a market one, and it’s very concrete: in Barcelona the demand for housing far outstrips supply, and prices, both to buy and to rent, have been under pressure for years. Meanwhile, there are thousands of empty or underused commercial ground floors, especially on streets that have lost retail activity.

For an owner, that opens a double opportunity: buying at a lower price than an equivalent home, and increasing the property’s value by turning it into a residential asset. A commercial space that yields little as a shop can be transformed into a home with a far higher market value.

To this we should add a design element that, personally, I love: ground floors tend to have high ceilings, wide façades and clear floor plans. Ha! They are a beautiful canvas for designing a bright, contemporary space. At Nomadas we’ve seen old workshops become homes that keep the trace of what they once were, and that dialogue between the historic and the new is exactly what we most enjoy working on.

But a deeper look reveals that this opportunity only materialises when the space meets the requirements. Let’s go through them.

The regulatory framework governing change of use in Barcelona

Before measuring a single metre, it’s worth knowing who’s in charge here. Change of use in Barcelona isn’t governed by a single law, but by a set of overlapping rules. And the golden rule when two rules contradict each other is this: the most restrictive one always applies.

Barcelona’s Metropolitan General Plan (PGM) and planning keys

The Metropolitan General Plan (PGM), approved in 1976, is the planning document that organises land uses in Barcelona and much of its metropolitan area. It’s the one that says, street by street and plot by plot, what can be done in each place.

The PGM assigns each area a planning key (clau urbanística), for example, key 13 for urban densification zones, or key 18 for specific volumetric zones. That key determines, among other things, whether residential use is allowed in your space and under what conditions. It’s the first filter: if your zone’s key doesn’t allow housing, the project isn’t feasible, no matter how perfect the space is inside.

Decree 141/2012 of the Generalitat: minimum habitability conditions

The Generalitat of Catalonia’s Decree 141/2012 regulates the minimum habitability conditions of dwellings. It’s the regional rule that defines what makes a space worthy of being lived in: minimum floor areas, heights, ventilation, bathroom and kitchen provision, and so on.

As a reference, the Decree sets the minimum floor area of a dwelling at 36 m² of usable space. Important: that’s the regional minimum. In Barcelona, as we’ll see, the figure goes up.

The Technical Building Code (CTE) and the Metropolitan By-laws

The Technical Building Code (CTE) is the national rule that establishes buildings’ requirements for safety and habitability: structural safety, fire safety, health and hygiene, noise protection and energy efficiency. A new dwelling created through a change of use must comply with it.

To this we add the Metropolitan Building By-laws (OME) and the municipal works and activities ordinance. These are the rules that fine-tune the details at a local scale and, in Barcelona’s case, tighten some parameters compared with the regional minimum.

The Horizontal Property Law and the homeowners’ association by-laws

Finally, it’s not all about planning. The Horizontal Property Law (LPH) governs the life of homeowners’ associations, and your community’s by-laws may contain clauses that directly affect your project.

Your space is a private element, but it sits inside a shared building. If the by-laws expressly forbid residential use on the ground floors, or if your works touch communal elements, the association enters the equation. We’ll develop this further below.

Planning requirements: the first thing you should check

If I had to give you a single piece of advice, it would be this: always start with the planning side. It’s the filter that decides whether your project lives or dies, and checking it costs little. Pushing ahead with the works without having verified it is the most expensive mistake you can make.

Planning key and compatibility of residential use in your area

The first step is to find out your plot’s planning key and whether that key allows residential use. There are areas of Barcelona where the planning expressly protects the commercial use of ground floors, for instance, along consolidated retail corridors, and there the change of use simply isn’t authorised.

You can make a first indicative check on Barcelona City Council’s Urban Information Portal (Portal d’Informació Urbanística, PIU), where each property’s classification can be consulted. But the careful reading of the regulations is done by an architect: a key may allow housing with nuances that only become visible by reading the full record.

Maximum housing density per plot: the limit that can block your project

This is, without exaggeration, the requirement that stops the most projects. Density is the maximum number of dwellings allowed on a plot or building. Even if your space is impeccable, if the building has already reached its housing cap, not one more will fit.

How is it calculated? You take the building’s above-ground built area and divide it by a module. In the metropolitan area the usual module is 100, but in the city of Barcelona the module is 80.

An example makes it clear: a building with 800 m² built above ground, divided by 80, gives a maximum of 10 dwellings. If the building has 9 or fewer, one more dwelling fits and the change of use is feasible. If it already has 10, there’s no margin.

In such cases, an architect can study alternatives, for instance, merging two existing dwellings to free up one density unit, but these are complex solutions that require the association’s agreement. That’s why it’s wise to check density before buying.

How to request the planning compatibility certificate from the City Council

The way to get an official answer is to request a planning compatibility certificate or report from the City Council. It’s a document that confirms, in black and white, whether residential use is compatible with your property’s classification.

Usually the architect who will draft the project handles it, because they know exactly what to ask and how to interpret the answer. It’s a relatively quick procedure and the most worthwhile investment of the whole process: it tells you, before you really start spending, whether your project has a future.

Physical and habitability requirements for the space

Once the planning filter is passed, the second big block arrives: does the space meet the physical conditions to be a decent home? Here Decree 141/2012, the CTE and the by-laws come into play. These are the points we look at most.

Minimum floor area: 40 m² of usable space in Barcelona

Decree 141/2012 sets the regional minimum at 36 m² of usable space. But in Barcelona the Metropolitan By-laws apply, raising that minimum to 40 m² of usable space. Since the most restrictive rule prevails, in the city of Barcelona the reference figure is 40 m² of usable space.

Watch the word usable: we’re talking about real walkable floor area, not built area. If your space is smaller, all is not lost, it’s sometimes possible to merge adjoining units, but it’s a serious constraint that must be resolved from the outset.

Minimum clear height: 2.50 m in main rooms and 2.20 m in secondary areas

The clear height, from finished floor to finished ceiling, must be at least 2.50 m in the main rooms (living room, bedrooms, kitchen). In secondary areas such as bathrooms, corridors or storage rooms, a minimum of 2.20 m is allowed.

It’s a point to watch, because commercial ground floors sometimes lose height when the new flooring, the false ceilings or the installations go in. You have to calculate the final height, once the renovation is done, not the height of the empty space.

Natural light and ventilation: 12% of floor area and minimum façade

A home has to have natural light and air. The regulations require habitable rooms to have a natural-light area equivalent to a percentage of the floor area (around 12%) through windows facing the exterior or compliant courtyards.

Linked to this is the minimum façade. To guarantee that light, a façade length proportional to the space’s floor area is required. A widely used rule of thumb is the space’s floor area divided by 9, adding exterior and interior façade. Here, the patis de mansana, the interior block courtyards that Cerdà designed in the Eixample, are great allies: many spaces draw light and ventilation from those interior green areas.

Smoke outlet for the kitchen and bathroom ventilation

The kitchen needs a smoke outlet and the bathrooms need ventilation. And here there’s a strict rule: the smoke outlet must rise to the building’s roof and can never run along the façade.

It can only be routed through enclosed plot courtyards, ventilation shafts (patinejos) or spaces intended for installations to pass through. If the duct has to cross communal elements of the building, you’ll need the association’s permission. Solving the smoke outlet well is one of the technical points that decides the project’s feasibility.

Accessibility: barrier-free access and lift regulations

The home must have safe and, as far as possible, barrier-free access. The accessibility regulations and the CTE set the conditions for the route from the public street to the door.

The good news for ground-floor projects is that they don’t depend on a lift: being at street level, they usually find it easier to meet accessibility than a flat on an upper floor. It is, in fact, one of the advantages of converting a ground floor.

Ground-floor location and the ban on basements

The last physical requirement, and an emphatic one: the space must be on the ground floor. Residential use in basements is not permitted in most municipalities, Barcelona included.

If your space has a ground floor and a basement, in some cases it’s possible to segregate the two floors so that only the ground floor becomes a home. But a basement, on its own, cannot become a home.

Legal and community requirements

Your space is yours, yes, but it lives inside a community. And that means that, besides the City Council, there’s another party worth involving from the start: your neighbours.

What the homeowners’ association says and when you need its approval

The general rule surprises many people: changing the use of a private element usually doesn’t require the association’s permission, unless the by-laws expressly forbid it. In most buildings, the by-laws say nothing on the matter, so the change of use itself doesn’t need a vote.

That said, there’s a big “but”. If your works affect communal elements (the structure, the façade, the entrance hall, or if the smoke outlet crosses communal areas) then you do need the association’s approval. And it’s very common for a change of use to touch one of these elements.

When unanimity of the owners is required

The most demanding case arises when the project involves modifying the community’s founding deed or by-laws. Under the Horizontal Property Law, that modification requires unanimity of the owners.

Obtaining the unanimity of an entire building can be, quite simply, the hardest part of the whole process. So, if your project is going to touch communal elements, the smart move is to talk to the association early, explain the scope of the works clearly, and review the by-laws with a professional before you commit.

Prior feasibility study: the step you can’t skip

I’ll say it loud and clear: the feasibility study is not optional. It’s the step that separates a solid project from a blind investment. And yet it’s the one most people try to skip to save money.

Planning feasibility: density, key and planning

The first layer of the study is the planning one: checking the plot’s key, verifying that residential use is allowed and calculating density to make sure one more dwelling fits in the building.

If this layer fails, no project is possible. That’s why it’s analysed first: it’s the quickest to review and the most decisive.

Physical feasibility: technical inspection and habitability conditions

The second layer is the physical one. Here the space is inspected on site to measure the real clear height, the available façade, the possibilities for light and ventilation, the condition of the structure and the feasibility of the smoke outlet.

This technical inspection is carried out by an architect or technical architect, and it’s the one that confirms, with data, not hunches, whether the space can comply with Decree 141/2012 and the CTE. It’s also worth reviewing the building’s general condition: if it has its ITE (Building Technical Inspection) in order, all the better.

Who carries out the study and how much it costs

The feasibility study is always carried out by a qualified professional: a registered architect or technical architect. It’s not something you can resolve on your own, because it requires interpreting both planning and habitability regulations.

The cost is modest compared with what’s at stake, and it’s often deducted later from the project fees. At Nomadas we always frame it this way: it’s the investment that protects you from spending tens of thousands of euros on works that couldn’t be legalised. Better to know on day one.

Step-by-step procedures to legalise the change of use

Here comes the roadmap. These are, in order, the procedures to legalise the change of use from a commercial space to a home in Barcelona.

Planning compatibility report (15–30 days)

The official starting point. You request the planning compatibility report from the City Council, which confirms whether residential use is admissible on your property. It usually takes around 15 to 30 days, depending on the council’s workload.

Technical project endorsed by a registered architect

With the planning green light, a registered architect drafts the technical change-of-use project: drawings, report and justification of compliance with all the regulations. That project is endorsed (visado) by the architects’ association, or validated through an ECA (a collaborating entity of the administration), before being submitted.

Major works licence with change of use: timeframes and fees

A change of use is always processed as a major works licence, never as a minor works one. The endorsed project is submitted to the City Council, along with the corresponding processing fee.

In Barcelona, the licence usually takes between 4 and 6 months to be granted, though it can drag on depending on the district and the volume of files. At this point the ICIO (Tax on Construction, Installations and Works) is settled, which in Barcelona is roughly 4% of the material execution budget (PEM).

Carrying out the renovation and the works completion certificate

With the licence granted, the works begin: structure, installations, insulation, joinery, kitchen, bathrooms and finishes. On completion, the architect issues the endorsed works completion certificate, which certifies that the renovation has been carried out in line with the approved project.

Habitability certificate for first occupancy after refurbishment

With the works finished and certified, you apply to the Generalitat for the habitability certificate —for first occupancy after refurbishment. This document is the one that officially certifies that the space meets the conditions to be lived in. Without the cèdula, there’s no legal home.

Notarial deeds, the Land Registry and the Cadastre

The final step is legal and registry-related. With the works completion certificate and the habitability certificate, you go to the notary to grant the new deeds reflecting the property as a dwelling. The Cadastre is then updated and the change is registered at the Land Registry.

At this stage the Stamp Duty (AJD) is settled, around 1,5% of the new home’s value. From here, and only from here, your former commercial space is officially a home.

Common mistakes and reasons for licence refusal

After seeing many projects, I can assure you that the reasons for refusal repeat themselves. Knowing them is the best way not to fall into them.

Exceeding the maximum permitted housing density

This is the number one reason for refusal in Barcelona. The owner renovates the space convinced everything is fine and, when applying for the licence, discovers that the building has already used up its housing quota. Checking density before buying avoids this disappointment entirely.

Failing to resolve the smoke outlet or the ventilation

A kitchen without a viable smoke outlet up to the roof, or rooms without the required natural light and ventilation, are clear grounds for refusal. These are technical problems that must be resolved in the project, not improvised on site.

Living in the space without having processed the change of use: risks and penalties

Many people renovate the space “on the inside” and move in to live there without processing anything. It’s a planning offence: the City Council can impose financial penalties and, in the most serious cases, order the restoration of the original use. On top of that, the space has no habitability certificate, so it can’t be sold or rented as a home. It doesn’t pay off.

Confusing the habitability certificate with the change-of-use licence

They are two distinct, non-interchangeable documents. The change-of-use licence authorises the works and the planning change; the habitability certificate certifies that the result is habitable. Having one doesn’t mean having the other: you need both.

Frequently asked questions

Can every commercial ground floor in Barcelona be converted into a home?

No. Feasibility depends on the area’s planning key, on the building’s density and on the space’s physical conditions. There are areas where the planning protects commercial use and the change isn’t authorised. Only a feasibility study confirms it case by case.

How long does it take for the change-of-use licence to be granted in Barcelona?

The major works licence with change of use usually takes between 4 and 6 months to be granted. If you add the feasibility study, drafting the project and carrying out the works, the full process usually runs to around a year.

Is the favourable vote of the whole homeowners’ association needed for the change of use?

Not always. Changing the use of a private element doesn’t require permission unless the by-laws forbid it. However, if the works affect communal elements, an agreement is needed, and if they involve modifying the founding deed or the by-laws, unanimity is required.

What happens if the space has less than 40 m² of usable area?

In Barcelona, 40 m² of usable area is the minimum. If your space falls short, one possible route is to merge adjoining units until you reach the necessary floor area. Without that solution, the change of use to an independent home won’t be feasible.

Can you live in the space while the change-of-use licence is being processed?

Not legally. Until the licence is granted, the works carried out and the habitability certificate issued, the property is still a commercial space. Living in it beforehand is a planning offence exposed to penalties.

Is the change of use taxed in income tax (IRPF) or in property tax (IBI)?

The procedure itself generates taxes such as the ICIO (on the works) and the AJD (on the new deeds). Once converted into a home, the property changes its classification for IBI purposes, which may alter its bill. For your specific tax situation (including income tax if you sell or rent) the prudent move is to consult a tax adviser.

What’s the difference between the habitability certificate and the change-of-use licence?

The change-of-use licence is the municipal permit that authorises the works and the planning transformation of the space. The habitability certificate is the Generalitat’s document that certifies the result meets the conditions to be lived in. You need both: one doesn’t replace the other.

Is it possible to convert a commercial space into a loft if the building has no lift?

Yes. Since it’s a space on the ground floor, at street level, the project doesn’t depend on a lift to meet accessibility. That is, precisely, one of the advantages of converting a commercial ground floor rather than renovating an upper-floor flat.

Converting a commercial ground floor into a home or loft is, when it’s done well, one of the most beautiful transformations there is: giving residential life back to a space the city had written off. But as you’ve seen, success lies in the order: first check, then design, and only then renovate.

At Nomadas Architecture we accompany this process from start to finish: feasibility study, technical project, licence processing and works supervision, bringing out what the space already has and adding a contemporary, bright design.

And now it’s your turn: do you have a commercial space in mind, or are you already mulling over the idea? Next time you walk through your neighbourhood, have you noticed those ground floors that seem to be crying out for a second life? Tell us what you think in the comments, we’d love to hear from you!

Some of it shows up as unexpected conversations. Clients question the building code with a confidence they didn’t have before, backed by arguments that weren’t part of the usual dialogue. “If the corridor only leads to a bathroom, it can be 60 cm wide,” they tell us. The line sounds convincing in the abstract. Regulation and construction don’t actually work that way.

The rest shows up in the inbox. Briefs now arrive with full AI-generated dossiers attached: floor plans, electrical schematics, plumbing proposals, even material specs. Well presented, coherent at first glance, and full of basic errors once you read them properly. Layouts that don’t function, dimensions that breach the building code, solutions that ignore how a built space behaves.

What both cases have in common isn’t the content. It’s the source. Answers pulled from AI systems that present themselves with total certainty, as if fluency were the same thing as accuracy.

Who hasn’t used an AI tool by now? Most of us have asked ChatGPT or Gemini to settle a quick doubt. These tools earn their place: they help you grasp a concept, organise information, and test ideas on the spot.

That same speed has a side effect, though. When an automatic answer gets taken as valid without any check, it can warp a decision from the very start of a project. It hits hardest on questions of regulation, planning, and feasibility.

The danger of AI in architecture isn’t the tool. It’s how people read its actual reach.

Understanding AI’s real impact on architectural practice

Consultation tool vs. technical judgment

AI works as a starting point. It doesn’t replace the technical judgment a specific case demands. In architecture almost no answer is universal: it depends on the urban context, the planning rules in force, and how those rules get read.

We see this constantly. Even the conversations with the district technicians who review projects rest on interpretation of the regulation. The personal element carries real weight in how technical criteria get applied.

Planning regulation isn’t a closed system. It’s an interpretive framework, and it needs experience, technical cross-checking, and actual sign-off from the administration.

The RIBA AI Report 2025 backs this up. Adoption among UK architecture practices jumped from 41% in 2024 to 59% in 2025, but RIBA frames AI’s role as augmenting professional work rather than replacing it, and flags real concerns around control, accountability, and technical decision-making (RIBA AI Report 2025).

AI, medicine, and architecture: comparable limits

The limits get clearer next to other complex fields. AI won’t replace a full medical diagnosis or a clinical assessment, and it won’t settle an architectural or planning question for good either. It can sketch a first outline. It can’t stand in for a complete analysis of the case.

In architecture that complexity comes from layers you only understand from practice:

• the specific regulation of the municipality and how it’s actually interpreted
• experience built up across similar projects
• direct observation of the space and its physical constraints
• reading the urban surroundings and how they behave
• dialogue with municipal technicians and the administration
• unwritten criteria you only learn by doing the work

Strip those out and any answer is partial, with a real risk of misjudging whether a project is even viable.

The illusion of instant knowledge

AI produces fast, tidy, confident-looking answers, and that polish can hide how involved the architectural process really is. The cost lands in the early stages, where you set expectations that are hard to walk back later.

General information isn’t the same as the regulation that applies to your case. A digital example isn’t proof your plot is viable. A render isn’t an approvable project.

RIBA names this same tension. AI is being adopted fast for analysis, drafting, and design support, and at the same time it introduces errors from missing context and a tendency to over-rely on automated output. Hence the case for constant human oversight.

Risks in interpreting planning regulations

Regulation as an interpretive system

One of the most common mistakes is treating planning regulation like a closed manual. In practice, a large part of the technical work is reading how that regulation applies to each specific case.

That reading often isn’t written down anywhere. It gets built through experience, through earlier projects, and through direct contact with municipal technicians.

Using AI uncritically for regulation and feasibility

AI tools have no access to local criteria, administrative precedent, or the practical interpretations of each municipality. So they can hand you answers that look right and aren’t, once you put them in a real context. An AI answer doesn’t replace a planning consultation or a technical sign-off on the project.

RIBA makes a related point: practices need clear policies on how they use AI, precisely to avoid these interpretation errors and keep technical accountability intact through the design process.

Theory vs. administrative reality

Regulation can read as perfectly clear in the abstract. Applying it depends on the urban context, the type of intervention, and how the administration interprets it. That’s why two similar projects can resolve in completely different ways.

Practical problems in decision-making

Confusing information with validation

A frequent error is assuming an AI answer equals an official confirmation. That gap creates expectations the project’s technical and legal reality won’t support.

Underestimating the complexity of the architectural process

A project isn’t a visual or a concept. It runs through technical, regulatory, and administrative stages that decide whether it’s viable at all: the planning analysis, the technical development of the project, the consultations with the administration, and the adjustments that come up during licensing.

Unrealistic project expectations

AI-generated images and explanations can be genuinely persuasive. They aren’t always compatible with the regulation or with the real construction limits of the site.

The role of technical judgment in a project

Interpretation as an essential part of the process

The value of the architectural process lives in interpreting the context and the regulation, not in reading either one literally. That interpretation is what turns an idea into a buildable project.

Validation with technicians and the administration

Plenty of decisions only get confirmed through accumulated experience, consultation with municipal technicians, and real work on comparable projects. Automated systems don’t hold that knowledge.

From quick information to responsible decisions

Architecture turns information into decisions you can stand behind, balancing expectations, regulation, and what you can actually build. What matters isn’t what AI suggests is possible. It’s what’s viable inside the technical, legal, and urban framework.

Strategies for a clearer relationship with your project

Use AI as a reference, not validation

Lean on AI for support. Don’t let it stand in for technical verification or for an informed decision.

Understand the invisible phases of a project

Behind every project sits technical work you rarely see: the regulatory analysis, the consultations, the adjustments, the progressive sign-offs.

Accept complexity as part of the process

Architecture is complex by nature. Working with that complexity, rather than around it, is what gets you to decisions that are realistic and safe.

FAQs

Can you trust AI to understand planning regulation?

Only as general orientation. It doesn’t replace the technical interpretation or the sign-off your specific case needs.

Why doesn’t the information online match what you tell me during the project?

Because regulation gets applied in context. It depends on technical criteria, experience, and how the administration handles it in practice.

Is regulation always fixed?

No. It’s interpretive, and it shifts with the municipality, the urban context, and how it’s technically applied case by case.

In this article I’ll explain, clearly, the building permits of Barcelona City Council (the Assabentat, the Immediate Notification, the Deferred Notification and the Major Works Licence), how they relate to the activity licence, what technical documentation you need, how much it all costs and how to legalise your commercial renovation without nasty surprises.

Why is it essential to process the permits before renovating your space?

Let me be direct: the building permit isn’t optional paperwork, it’s a municipal authorisation without which the works are, quite simply, illegal. And renovating first to “legalise it later” is one of the decisions that ends up costing the most.

Processing the right permit before you start protects you on three fronts. First, financially: you avoid penalties and the dreaded suspension of the works, which sends costs soaring and delays the opening. Second, technically: the procedure forces a check that your project complies with the regulations on safety, accessibility and installations, something that protects both your future customers and you. And third, in asset terms: a space with a legalised renovation can be sold, rented and transferred without obstacles; one with irregular works cannot.

There’s a fact that sums it up well: many businesses delay their opening not because of the works themselves, but because they didn’t correctly classify the type of permit from the start. Beginning with the procedure isn’t losing time: it’s gaining it.

Types of building permit at Barcelona City Council

First of all, a golden tip: the first step is always the prior consultation (consulta prèvia) at Barcelona City Council. That procedure tells you, depending on the type of works and the location of the space, which specific permit you need and what documentation you’ll have to submit. Don’t skip it.

The City Council classifies works according to their complexity and, to each level, a different procedure corresponds. These are the four you should know.

1. Notification or ‘Assabentat’

The notification (Assabentat in Catalan, the term you’ll see on the municipal portal) is the simplest procedure. It’s reserved for minor works of type III: renovations that don’t modify the layout, the structure or the façade of the space.

We’re talking about painting, changing the flooring, renewing tiling, replacing interior joinery or updating installations without altering their routing. It’s processed online, requires no technical documentation, lets you start the works the next day and is valid for three months. Fast and inexpensive.

2. Immediate Notification

The Immediate Notification (Comunicat Immediat) corresponds to minor works of type II: those that change the layout of the space without touching the structure or the building’s architectural configuration.

This covers moving partitions, installation work of a certain scale, the repair of façade elements, or the installation of signs and awnings. Unlike the Assabentat, it does need documentation: a professional must first process a Technical Suitability Report (IIT) and then the building permit. The process takes around 15 to 30 days; once the fees are paid, the works can begin almost immediately.

3. Deferred Notification

The Deferred Notification (Comunicat Diferit) applies to minor works of type I, a step up: renovations that involve a partial modification of the building’s structure, the division of ground-floor spaces, the installation of interior lifts, or renovations of spaces subject to planning limitations.

It also requires a professional to process the Technical Suitability Report and, afterwards, the permit. The timeframe is similar, around 20 to 30 days, but with one key difference from the immediate version: once the procedure is submitted and the fees paid, the City Council has one month to review the documentation before the works are fully compliant.

4. Major Works Licence (structural changes)

The Major Works Licence is the most demanding procedure and is reserved for major works: large-scale or technically complex jobs that require a project.

It’s the one that applies, for example, to large refurbishments, façade modifications, extensions in height or volume, the installation of exterior lifts, the change of use from commercial space to dwelling, or the division and segregation of premises. Here a senior professional must draft a full executive project before applying for the permit, and the City Council resolves through the general procedure in around two months.

The Activity and Opening Licence: the indispensable parallel procedure

Here comes one of the most frequent misunderstandings, and I want to make it clear: the building permit doesn’t authorise you to open the business. They are two distinct procedures that run in parallel.

The building permit authorises the physical renovation of the space. The activity and opening licence authorises the use you’re going to give that space and certifies that the activity complies with the regulations on safety, noise, hygiene and accessibility. Without it, you can’t open, no matter how finished and beautiful the renovation is.

The type of activity procedure depends on how much impact your business has. An activity considered harmless (a clothes shop, a small office) is usually resolved with a notification, which is relatively quick. By contrast, a restaurant, a bar or a gym are activities with more demands: they need additional reports (acoustic, fire safety, evacuation plans) and their timeframes stretch to several months.

My advice, and what we always do at Nomadas, is to plan both procedures together from day one. Designing the renovation without thinking about the requirements of the future activity is the surest way to end up having to redo things.

Special cases: spaces in protected or heritage buildings

Barcelona is a city of historical layers, and that means a great many commercial spaces sit in listed buildings. If your space occupies the ground floor of one of them, the process changes.

When the building has some degree of heritage protection, in addition to the ordinary building permit a prior report from the City Council’s Heritage Department is required. That report assesses whether your intervention respects the building’s protected values, and its resolution lengthens the timeframes: the City Council usually resolves through the general procedure in around three months.

You can check whether a building is listed in Barcelona’s Architectural Heritage Finder before buying or renting. And here’s a thought that matters to me: heritage isn’t an obstacle, it’s an asset. A modernista façade, a Catalan vault or an original hydraulic-tile floor are exactly what give a space its character. At Nomadas we work hard on that idea of bringing out the historic and combining it with contemporary design. It’s well worth it!

Mandatory technical documentation and legal requirements

But a deeper look at any procedure other than the Assabentat reveals that the heart of the permit is the technical documentation. Without it, there’s no licence. These are the two key documents.

The Technical Suitability Report (IIT)

The Technical Suitability Report (IIT) is the document that verifies that your project complies with the regulations before submitting it to the City Council. It works as a prior quality control.

It’s issued by collaborating entities accredited by the Administration, and it’s mandatory for the Immediate Notification and the Deferred Notification. Its purpose is to filter out errors before the file reaches the council, which speeds up processing considerably. In fact, a large share of licence delays are caused precisely by faults in the technical documentation that a good IIT catches in time.

The endorsed technical project (architecture and engineering)

For the Major Works Licence, the central document is the technical project, drafted and signed by a registered architect or engineer and endorsed (visado) by their professional association.

That project isn’t a mere drawing: it includes the descriptive report, the structural and installation calculations, and the justification of compliance with all the applicable regulations. To it are added other common documents, depending on the scope of the works: the energy efficiency certificate, the accessibility report, the certificates for the electrical and gas installations, the health and safety study and, on completion, the works completion certificate signed by the site management.

How much does a commercial building licence cost in Barcelona?

It’s the million-euro question, and the honest answer is: it depends on the type of permit, the floor area of the space and the scope of the renovation. But I can give you an indicative order of magnitude.

The total cost of a licence has several parts: the municipal processing fees, the professional fees for whoever prepares the IIT or the project, and the ICIO (Tax on Construction, Installations and Works), which in Barcelona is roughly 4% of the material execution budget of the works.

These figures are indicative and don’t include the ICIO nor, where applicable, the full architecture fees. 

Step-by-step checklist to legalise your commercial renovation without delays

So you have the whole process at a glance, this is the order worth following:

1. Prior consultation at the City Council. First of all, find out which permit your works need and what documentation you’ll be asked for.
2. Check the situation of the space and the building. Verify the Cadastre, whether the building is listed, and what activity licence the space previously held.
3. Define the project and classify the works. With your professional, decide the scope of the renovation and which type of permit it corresponds to.
4. Commission the technical documentation. The Technical Suitability Report or the endorsed executive project, as the case may be.
5. Submit the procedure and pay the fees and the ICIO. With everything in order, register the permit with the City Council.
6. Carry out the renovation. Always within what’s authorised in the granted permit.
7. Obtain the works completion certificate and process the activity and opening licence or notification before opening to the public.

Following this order, and not improvising, is what separates a punctual opening from one full of delays.

Fines and penalties for carrying out illegal works in commercial spaces

Let’s talk plainly about what happens if you skip the permits, because the consequences are serious and worth knowing.

Carrying out works without a licence is a planning offence. The City Council can impose financial penalties that vary according to the severity and the scale of the works (they can range from a few hundred to several thousand euros) and, in addition, order the immediate suspension of the works until the situation is regularised.

In the most serious cases, the consequence can even be the obligation to restore the space to its original state, that is, to undo the renovation. To all this is added a downside many people forget: a space with unlegalised works carries problems for selling, renting or transferring it, because the irregularity surfaces in any check.

The good news? In many cases, a renovation that’s already been carried out can be legalised after the fact through a regularisation file. It’s more expensive and slower than having done it properly from the start (hence the recurring advice) but it has a solution.

Frequently Asked Questions (FAQs)

Can I start the renovation of my space on the same day I submit the procedure?

It depends on the permit. With the Assabentat you can start practically the next day. With the Immediate Notification you can also begin the works straight away once the fees are paid and the Technical Suitability Report is processed. The Major Works Licence, by contrast, requires waiting for the City Council’s resolution.

What happens if I renovate the space without requesting any permit?

You would be committing a planning offence. You expose yourself to financial penalties, to the suspension of the works and, in the most serious cases, to the obligation to return the space to its original state. On top of that, you’ll have problems selling, renting or transferring the space until the situation is regularised.

Does the building permit also allow me to open the business?

No. They are two distinct procedures. The building permit authorises the physical renovation; to open and operate you also need the activity and opening licence or notification, which certifies that your business complies with the regulations on safety, noise and accessibility.

How long does a Major Works Licence take to be granted in Barcelona?

The City Council usually resolves through the general procedure in around 2-3 months from the submission of the complete file. If the building is listed as heritage, the timeframe stretches to about three months because of the prior report from the Heritage Department. To those timeframes you must add the time to draft the technical project.

Do I need a permit to change the sign or the façade of my space?

Yes. Installing signs and awnings or repairing façade elements falls, at the very least, under an Immediate Notification. And if the building is protected, any intervention on the façade will also need the approval of the Heritage Department.

Who issues the Technical Suitability Report?

The IIT is issued by collaborating entities accredited by the Administration, based on the documentation your professional prepares. It’s a prior quality control that verifies the project complies with the regulations before it’s submitted to the City Council.

Can I legalise a commercial renovation I’ve already carried out without a permit?

In many cases, yes. There’s the route of regularisation: a professional prepares the necessary documentation and the file is processed after the fact, paying the corresponding fees. It’s more costly and slower than processing it in time, but it lets you bring the space into order.

What permit do I need if I’m only going to paint and change the flooring?

If the renovation doesn’t modify the layout, the structure or the façade, the simplest procedure applies: the Notification or Assabentat. It requires no technical documentation and lets you start the works almost immediately.

Renovating a commercial space in Barcelona is a beautiful adventure (the moment a space starts to look like the business you imagined) but that adventure is built on a not-very-glamorous and very important foundation: the right permits, processed in the right order.

At Nomadas Architecture we accompany the whole process: we classify the works, prepare the technical documentation, manage the licences and supervise the renovation, so that you can focus on what really matters, which is your project.

And now tell me: are you mulling over the renovation of a commercial space? Do you have doubts about which permit would apply to you, or about a specific case? Leave us your question in the comments, we’ll be delighted to help!