I have a habit: when I walk through Barcelona, I look at the ground floors. And for a few years now I have been noticing something I didn’t see as often before. Old shop shutters that no longer roll up to sell anything, but instead hide curtains, plants on the windowsill and, sometimes, a bike parked in the hallway. That old haberdashery on the barri is now someone’s home.
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.
| Concept | What it is | What the regulations require |
| Dwelling | A space intended for residence with all functions (rest, cooking, hygiene) | Compliance with Decree 141/2012 and the by-laws; minimum of 40 m² of usable floor area in Barcelona |
| Loft | An open-plan dwelling, undivided | It is a dwelling in every respect: the same habitability requirements apply |
| Studio / single-person dwelling | A minimal dwelling with a single living space | Also a dwelling; it allows some floor-area particularities, but it still needs a habitability certificate |
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!
