How to convert commercial premises into a home in Barcelona: requirements, regulations and process (2026 guide)

By Sergio Sanz and Pau Martínez, architects · Published 1 October 2025 · Updated 27 October 2026

Can you convert commercial premises into a home in Barcelona? Yes, but not just any premises. For a ground-floor shop, an office or a workshop to legally become a flat, five pieces have to fit together: urban planning (it must allow one more dwelling in the building), the Metropolitan Building Ordinances, habitability (Decree 141/2012), the Spanish Building Code (CTE) and the bylaws of the owners’ association. If a single one fails, the change of use from commercial to residential will not go ahead, however good the design is.

In this guide we explain each requirement with its figures and the rule behind it, what the project includes, the whole process step by step —from the first check to the new title deed— and the reasons why most projects fall through. It has been written jointly by Sergio Sanz and Pau Martínez, architects and partners at Kaitek Arquitectura, drawing on the changes of use we study, design and manage in Barcelona and its metropolitan area.

1. Can you convert commercial premises into a home? Not always

No. Being empty, having a good ceiling height or facing the street does not mean that premises can become a home. Before buying premises or an office to convert, or investing in a project, you need to check three things that do not depend on the refurbishment and that, if they fail, cannot be fixed:

1. Planning must allow one more dwelling in the building. Each plot has a maximum number of dwellings (density). If the building has already reached it, no new dwelling can be created, even if the premises meet every other requirement.
2. The street and the floor must allow it. Some amendments to the Metropolitan General Plan (PGM) approved for specific neighbourhoods ban homes on the ground floor of certain streets, and listed buildings have their own restrictions.
3. The bylaws of the owners’ association must not forbid it. In Catalonia, the bylaws can set the use of the commercial units (art. 553-11 of the Civil Code of Catalonia).

Once past that filter, the technical requirements come into play —floor area, frontage, natural light, ventilation, kitchen extraction, insulation— and these can often be solved with a good design. That is why we always recommend a preliminary feasibility study first.

2. The first step: a preliminary feasibility study

Before buying the premises or commissioning the full project, it is worth carrying out a preliminary feasibility study. It is the cheapest way to find out whether you can convert commercial premises into a home and under what conditions. We do it in three stages, and at the end of each one we assess feasibility: if the result is negative, the project is dropped before spending any more.

• Stage A. Archives and planning status. Search of the municipal historical archive (the original building project and later licences), the Cadastre and aerial photographs; preliminary calculation of the dwelling density and assessment of the planning status of the building.
• Stage B. Background and site visit. Review of the owner’s documents (deeds, land registry extract, drawings, bylaws), visit to the premises, measured survey, detailed density calculation and assessment of the construction issues that may limit feasibility: clear ceiling height, light and ventilation, kitchen extraction, access, damp.
• Stage C. Outline design. Proposed layout, sizing of the habitable rooms and of the building services according to municipal, Catalan and Spanish regulations and, if needed, a consultation with the council’s technical staff.

The use stated in the deed is not always the legal use

One of the reasons to start with the archives is that the use stated in the title deed does not always match the legal planning use, which is the one recorded in the original building project and in the licences granted. In some feasibility studies we have found that the change of use was not needed: although the deed described commercial premises, the municipal archive and the planning licences recorded it as a dwelling, and it was enough to correct the description.

But be careful, because the opposite can also happen: not everything registered as a home is legally a home.

Only the licence gives full certainty about the administrative feasibility of a change of use: the preliminary study reflects the architect’s technical judgement and the way council officers interpret the regulations, and greatly reduces the risk.

3. Planning requirements to convert commercial premises into a home in Barcelona

Barcelona City Council sums up the requirements in its basic information guide on change of use to residential. They are:

Minimum usable floor area of 40 m² and minimum frontage of 3 m

The first additional provision of the 2004 amendment to the PGM Planning Regulations requires every new home to have at least 40 m² of usable floor area and a minimum frontage of 3 m to the street or to the inner block courtyard (light wells do not count). This is stricter than the general habitability minimum in Catalonia (36 m²). Enclosed bay windows and galleries do not count towards the minimum area of the rooms they are attached to.

Density: the maximum number of dwellings in the building

This is the requirement that most often prevents converting commercial premises into a home. The number of permitted dwellings is calculated by dividing the built floor area (or permitted floor area) of the plot by the planning density module; where the zone does not set another one, article 180 of the Metropolitan Building Ordinances refers to 80 m² of floor area per dwelling.

The project must show how many dwellings the building had in its original project (checked at the Contemporary Municipal Archive or the district archive) and how many have been added since, and demonstrate that the new one does not exceed the maximum. We explain this in more detail in built floor area and buildable floor area.

Ground-floor homes: the inner block courtyard

In areas regulated by street alignment, article 225.7 of the PGM Planning Regulations states that, if the living room or a bedroom of a ground-floor home opens onto the inner block, the part of that open space belonging to the plot must remain unbuilt, with a minimum of 6 m deep and 4.5 m wide in front of those rooms. Many ground floors in the Eixample cover the whole courtyard with single-storey extensions: in that case the main rooms have to open onto the street.

Neighbourhood amendments to the PGM

Some neighbourhoods have their own rules. The PGM amendment for Clot-Camp de l’Arpa (2025), for example, bans ground-floor homes on streets with certain zoning codes, and other neighbourhoods, such as Gràcia, have specific conditions for ground-floor homes. That is why the preliminary study always starts with the planning rules for that specific building.

Whole buildings, listed buildings and non-conforming buildings

• If a whole building changes use or is refurbished, the affordable housing reserve of the 2018 PGM amendment (art. 285 ter of the Planning Regulations) may apply.
• In listed buildings only the works and intervention criteria in their Heritage Catalogue record are allowed.
• If the building is non-conforming because of a new street alignment, the limits of the Catalan Planning Act (art. 108.4 of the consolidated text) apply, and it is worth checking with the district’s technical services.

Façade, signs and ducts: the urban landscape bylaw

Barcelona’s Urban Landscape Uses Bylaw (OUPU) does not allow equipment or ducts on the façade without express authorisation: kitchen extraction flues and air conditioning units on the façade are only allowed with an integration project approved by the City Council. In practice, kitchen extraction and air conditioning units must go up to the roof, and that requires the owners’ association.

4. Habitability requirements: Decree 141/2012

To convert commercial premises into a home, the resulting dwelling must meet the minimum habitability conditions of Decree 141/2012 of 30 October. In a change of use, the same conditions as for a new home (annex 1) apply, with some adjustments (annex 4). The most relevant are:

If the whole home is a single open space (a loft), it must allow an 8 m² bedroom to be partitioned off without the living room or the bedroom falling below their minimums. And the requirement that rules out the most premises is direct natural light and ventilation: in a very deep ground floor, with a street frontage only and no courtyard, the rooms at the back cannot be bedrooms.

When the works are finished, compliance with these conditions is certified by the habitability certificate (cédula de habitabilidad) for first occupancy following a change of use.

5. The Metropolitan Building Ordinances (OME)

In Barcelona and the other municipalities of the metropolitan area, in addition to Decree 141/2012, the Metropolitan Building Ordinances (OME) apply. The Metropolitan Area publishes them in its planning regulations portal (NUMAMB). The Metropolitan Refurbishment Ordinance (art. 14) requires newly created homes to comply with the OME, and a home resulting from a change of use is a newly created home. On some points the OME are stricter than the Decree, so the more restrictive of the two prevails.

Functional programme and minimum areas

The OME set minimum areas according to the number of people the home is designed for (the functional programme), which depends on the bedrooms:

Other OME conditions that affect commercial premises

• Daylight: habitable rooms, and also kitchens, storerooms and closets over 5 m², need a window area of at least 1/8 of their usable area, with absolute minimums of 1 m² (small rooms), 1.25 m² (10 to 14 m²) and 1.75 m² (over 14 m²) (art. 60).
• Courtyards: bedrooms and living rooms cannot be ventilated through courtyards under 3 m in diameter, nor kitchens through courtyards under 2.5 m.
• Main bedroom and living room: the double bedroom must have at least 10 m² and an inscribed circle of 2.60 m (art. 64); the living room, a circle of 2.70 m and 2.00 m of contact with the façade (art. 65).
• Kitchen and drying area: kitchen flue up to the roof (art. 66) and a clothes-drying space of at least 3.50 m², screened if it is on the façade (art. 65.5).
• Bathroom: at least one full bathroom that can be reached without going through the bedrooms or the kitchen (art. 67).
• Ground floor on the soil: if there is no basement below, the floor must be protected from damp with a 15 cm concrete slab over 15 cm of drainage gravel, or with a ventilated air gap of at least 15 cm (art. 69).

6. The Spanish Building Code in a change of use

The Spanish Building Code (CTE) applies to changes of use. Its part I (art. 2.5) distinguishes two cases: if the use of the whole building changes, all the basic requirements apply; if only part of it changes —the usual case when you convert commercial premises into a home—, each Basic Document (DB) states what applies. In practice, these are the points that shape the project:

Energy saving (DB HE)

The thermal envelope of the new home (façade, ground slab, party walls with unheated spaces, ceiling over the commercial unit or car park below) must meet the limit U-values of DB HE 1 even if it is not being altered. That is why the floor and the façade almost always need insulating and the shop-front glazing has to be replaced.

If an existing element cannot reach the limit, this is justified with the flexibility criteria of the DB itself. And if the home exceeds 50 m² of usable area, DB HE 0 on energy consumption also applies. More details in what an energy efficiency study is.

Health (DB HS): fumes, ventilation and radon

• Kitchen extraction: the cooker hood must connect to an independent duct that exits through the roof, with its outlet 3 m away from air intakes, windows and terraces (DB HS 3). This is one of the critical points: you need to find a route through a courtyard or a services shaft up to the roof and get the owners’ association on board.
• Ventilation: the home needs a ventilation system that ensures indoor air quality (supply through the living rooms and bedrooms, extraction through bathrooms and kitchen).
• Radon gas: premises in contact with the ground must apply DB HS 6. Barcelona is zone I (radon protection barrier), and some municipalities in the metropolitan area, such as Badalona or Santa Coloma de Gramenet, are zone II, which is stricter.

Noise protection (DB HR)

In a partial change of use DB HR is not strictly mandatory, but the guide to the document itself recommends applying its requirements. And it is common sense: if the home adjoins another shop, a bar or a car park, it is worth achieving airborne sound insulation of at least 55 dBA.

Fire safety (DB SI)

The new home must be separated from the other homes and from other uses (shops, car parks) by elements with adequate fire resistance —at least EI 60 between homes— and its escape routes must comply with DB SI. In existing residential buildings, the common escape routes do not need to be upgraded because a home is created in a commercial unit. Barcelona’s municipal fire protection bylaw also applies.

Structure (DB SE) and safety in use (DB SUA)

Going from retail to residential reduces the imposed load (from 5 to 2 kN/m²), so the structure is rarely a problem; it is, however, when openings are made in load-bearing walls, columns are removed or a mezzanine is added. DB SUA sets, among other things, floor slip resistance and railing heights.

7. Accessibility: the Catalan Accessibility Code

When you convert commercial premises into a home, the Catalan Accessibility Code (Decree 209/2023) also applies:

• Inside the home: every newly created home must have a practicable layout: 0.80 m entrance door, 0.80 m passages, 1.20 m obstacle-free circles at the entrance, in one bathroom, the kitchen, the living room and one bedroom (art. 84.2).
• Access from the street: under the interpretation criteria published by the Generalitat in 2026, if the premises had a single entrance step it can be kept; if there were two or more, a practicable access must be provided with a ramp, a platform lift or space reserved for one, which sometimes means setting the door back.
• Common areas: if the change of use increases the number of homes in the building by more than 50 %, the common areas serving the homes must be adapted (art. 78). Homes with direct access from the street that do not use the common areas are not counted.

8. The owners’ association: what it has a say on

To convert commercial premises into a home in a building under horizontal property, you have to involve the owners’ association. In Catalonia, horizontal property is governed by book five of the Civil Code of Catalonia (arts. 553-1 to 553-59), not by the Spanish Horizontal Property Act. Three articles are key:

• Art. 553-11: the bylaws can set the use of the private units and restrict their activities. If they say the commercial units are for retail use, the change of use requires amending them.
• Art. 553-36: owners can carry out works in their unit as long as they do not harm the others, safety, accessibility or the external appearance of the building, notifying the chair or the property manager beforehand. If the works affect common elements —façade, courtyard, roof, ducts, structure—, a resolution of the general meeting is needed.
• Arts. 553-25 and 553-26: set the majorities. Depending on the resolution, it ranges from a simple majority to unanimity or four fifths, and absent owners who do not object within one month count as votes in favour.

Requesting these authorisations from the association is the owner’s responsibility (as developer of the works). It is worth reviewing the bylaws and the land registry extract before buying and, if a duct has to run through the courtyard or the roof, raising it early at the general meeting.

9. What the project to convert commercial premises into a home includes

A change of use is not a simple refurbishment: the project has to demonstrate compliance with all the regulations above before the City Council and serve to build and supervise the works. These are the documents and services it is made of:

Basic project (to apply for the licence)

• Descriptive report of the works and compliance report for planning, the OME, Decree 141/2012, the CTE and the Accessibility Code.
• Site plan, floor plans, elevations and sections, dimensioned and to scale.
• Preliminary cost estimate by refurbished area, using the Architects’ Association modules.
• Basic health and safety study (Royal Decree 1627/1997) and waste management study (Decree 89/2010).
• Application for and processing of the planning licence.

Construction documents (to build)

Depending on the complexity of the premises and of the commission, there are two levels:

• Construction documents: bill of quantities by chapters and items with unit prices, and standard detail drawings. Enough to obtain comparable quotes from several builders for simple premises.
• Full construction project: in addition, a construction report, finishes drawings, services drawings and trade drawings (joinery, metalwork, furniture), structural drawings if needed, specifications for the building contract, user and maintenance instructions, and a quality control plan.

Site supervision

The architect takes on the site supervision: regular visits, site minutes recording instructions and who is responsible for each task, review of the builder’s valuations (in the full project) and issue of the final completion certificate, essential for first occupancy and the cédula.

Municipal fees and taxes, professional association approval (visado) when required and, where applicable, control bodies are not included in the professional fees.

10. How to convert commercial premises into a home, step by step

Step 1. Preliminary feasibility study

Archives, planning, density, site visit and outline design, as explained in section 2. The result is a yes, a no or a «yes, under these conditions».

Step 2. Project and agreements with the owners’ association

The architect prepares the basic project and the construction documents (section 9). With the project, the owner asks the association for any resolutions needed.

Step 3. Planning licence

In Barcelona, a change of use to residential always requires a planning licence with a project signed by a qualified professional, and the municipal works bylaw requires a prior planning report for refurbishments involving a change of use. The legal deadline for a decision is two months (three if a fire prevention report is needed), although requests for corrections suspend it. When applying, you pay the licence fee and the construction tax (ICIO), which in Barcelona is 4 % of the construction budget.

Step 4. Works under professional supervision

The works are carried out under site supervision and construction management, with health and safety coordination. This is when the insulation, building services, kitchen extraction, radon barrier and new windows are installed. If the building dates from before 2002, check whether there is asbestos in the elements to be altered. On the sequence of the works, see the stages of a refurbishment.

Step 5. Completion, first occupancy and habitability certificate

When the works are finished, the supervising architects issue the final completion certificate and first occupancy is notified to the City Council. With this, you apply for the first-occupancy cédula de habitabilidad for a change of use (Generalitat information), essential to contract utilities as a home, rent it out or sell it. The installation certificates and the energy performance certificate are also issued.

Step 6. Deed, Land Registry and Cadastre

With the licence, the completion certificate and the cédula, the premises can be registered as a home before a notary (amending the description of the private unit), the new use entered in the Land Registry and declared to the Cadastre. From then on, the former commercial premises are, for all purposes, a home.

11. How much does it cost and how long does it take to convert commercial premises into a home?

Every property is different, but as a guide, converting commercial premises into a home involves these timescales:

In total, between 8 and 14 months. As for the cost, you should allow for these items:

• Works: depends mainly on the condition of the premises and what needs solving (insulation, complete services, kitchen extraction, access, bathrooms and kitchen).
• Professional fees: feasibility study, project and site supervision. See what an architect’s fees are.
• Municipal taxes and fees: ICIO (4 % of the construction budget in Barcelona) and the licence fee.
• Professional association approval and control bodies, when required.
• Completion: installation certificates, energy certificate and habitability certificate.
• Notary, Land Registry and Cadastre.

At Kaitek, fees are paid in stages: first the feasibility study and the project, then the site supervision at the start of and during the works. If the feasibility study was commissioned and paid for separately beforehand, its cost is deducted from the project, and if the result is negative at any stage, the client can choose not to continue.

12. The most common reasons why a change of use does not go ahead

When you cannot convert commercial premises into a home, it is almost always for one of these reasons:

1. The building has already used up its density of dwellings.
2. The premises have less than 3 m of frontage or fall short of 40 m² of usable area.
3. The main rooms cannot get natural light and ventilation (very deep premises with no courtyard, or a built-over block courtyard).
4. There is no way to take the kitchen extraction up to the roof.
5. The bylaws forbid it and the owners’ association will not amend them.
6. A neighbourhood PGM amendment does not allow ground-floor homes on that street, or the building is listed.
7. The clear ceiling height is below 2.40 m and cannot be increased (for example, by lowering the floor).

We look at each of them in depth in the most common problems when converting commercial premises into a home. If you are buying premises to convert, you may also be interested in our due diligence before buying.

13. How Kaitek Arquitectura can help

We are a Barcelona architecture practice with more than 20 years of experience in refurbishment, building inspections and changes of use from commercial to residential. We carry out the feasibility study before you buy or invest, prepare the project, obtain the licence, supervise the works and handle the habitability certificate until the premises are legally a home. All our work is signed by architects registered with the COAC. If you want to convert commercial premises into a home, tell us about your case.

Frequently asked questions about converting commercial premises into a home

Regulations cited: Barcelona City Council, basic information on change of use to residential · Metropolitan Building Ordinances (AMB) · Habitability Decree 141/2012 · Spanish Building Code · Catalan Accessibility Code · Civil Code of Catalonia, book five · Urban Landscape Uses Bylaw. Reviewed in October 2026.