Is That Studio Apartment Even Legal? Minimum Square Meters, Light and Ventilation in Uruguay
INGAR · · Legal
Short answer: current national law sets a minimum habitable floor area of 25 m² for studio apartments. One bedroom: 35 m². Every additional bedroom adds 15 m².
That said, you can't declare a unit illegal just by reading a listing. First you need to establish whether it's being offered as an independent dwelling, how the square meters were measured, what the approved plans show, and what the local departmental code requires.
With that caveat: if someone offers you a "studio apartment" of 12 or 15 m², with no adequate light or ventilation, that's reason enough not to sign until the situation is cleared up.
What minimum size the law sets
Article 18 of Ley 13.728 (Uruguay's national housing law), as currently worded:
| Unit type | Minimum habitable floor area |
|---|---|
| Studio | 25 m² |
| One bedroom | 35 m² |
| Two bedrooms | 50 m² |
| Three bedrooms | 65 m² |
| Each additional bedroom | +15 m² |
Here's a detail that rarely gets spelled out, and it changes how you should read any older building: even though Ley 13.728 dates from 1968, the specific 25 m² floor for studios has not been on the books since then. It was introduced by article 228 of Ley 19.996 and has been in force since January 1, 2022.
The law itself is explicit that these are floors, not ceilings: national or departmental regulations can set the bar higher.
Where the law stands: as of August 1, 2026, the minimum in force is still 25 m². A bill under consideration would raise it to 35 m², but it has not passed.
What "habitable floor area" means
The legal 25 m² is not 25 m² of clear space measured wall to wall.
Under article 19 of Ley 13.728, habitable floor area covers bedrooms; the bathroom; an enclosed kitchen; dining and living areas; hallways and entry space; closets, cabinets and interior storage; interior walls; and the thickness of the walls enclosing the unit, out to their exterior face.
That's why the legal habitable area, the built area, the cadastral area and whatever you measure with a tape during a showing can all differ. The number in the listing is a starting reference; the approved plan is the document that counts.
A studio is not a room
This distinction clears up half the confusion out there.
A studio apartment is an independent dwelling: it has a bathroom, a kitchen and whatever else it needs to function as a self-contained housing unit.
A room is part of a house, a residence hall, a pensión (rooming house) or some other establishment. The 25 m² minimum for a full dwelling doesn't automatically apply to it, and it may fall under a different set of rules and operating permits.
Before you conclude anything, ask:
- Is what's for rent an independent unit or a room?
- Does it have its own padrón (property registry number), or is it part of another property?
- Does it have its own bathroom and kitchen?
- Does it appear as an independent dwelling on the plans?
- If it's a pensión or residence hall, does it hold the required operating permit?
A listing that says "studio" proves precisely nothing about the legal status of the space.
Natural light and ventilation: similar, but not the same
Ley 13.728 requires that bedrooms, living rooms, dining rooms and kitchens have openings of transparent or translucent material that let in sufficient natural light. It also requires that every room have natural or mechanical ventilation capable of maintaining sanitary conditions and clearing odors.
Each department is free to layer on more specific requirements.
What Montevideo requires
Article D.3317 of the Digesto Departamental (Montevideo's municipal code) states that every habitable room must have its own light source and draw air and light from open space.
Where the room opens directly onto that space, the opening must have a clear area of at least one tenth of the room's floor area, and part of it has to be operable so the room can be ventilated.
In plain terms: in Montevideo, the main room of a studio can't be solved with a light bulb and an exhaust fan.
Does the bathroom need a window?
Not necessarily. In Montevideo a bathroom doesn't require natural light, but it does have to ventilate: either through an opening onto open space or through a code-compliant duct.
Article D.3327 goes further and requires permanent ventilation. Which is why spotting an exhaust fan isn't enough: you need to know where it discharges and whether the system was properly designed.
Specific minimum dimensions in Montevideo
On top of the 25 m² total, article D.3310 sets the following for single-room dwellings:
| Element | Minimum requirement |
|---|---|
| Single habitable room | 14 m² |
| Minimum room dimension | 2,50 m |
| Main bathroom | 2,40 m² |
| Minimum bathroom dimension | 1,20 m |
| Kitchen | 3 m² |
| Minimum kitchen dimension | 1,40 m |
How these dimensions play out in practice — with an open kitchen, for instance — comes down to the design and the approved plan, not to someone's off-the-cuff reading at a front desk.
For habitable rooms, the general minimum ceiling height in Montevideo is 2,40 m; sloped ceilings are governed by specific rules on average and minimum height.
So, is a 12 m² studio with no window legal?
If it's being offered as an independent dwelling under current rules: 12 m² falls short of the national 25 m² minimum. And in Montevideo, a main room without direct light and ventilation wouldn't meet the requirements in force for habitable rooms either.
But the listing alone doesn't settle it. The published square footage may simply be wrong; it may be a room rather than a dwelling; there may be a gap between interior area and habitable area; the building may predate the rules and have approved records behind it; the unit may have been subdivided without authorization; or there may be a regularization process or special regime worth examining.
The prudent conclusion: 12 m² with no code-compliant opening is a serious red flag if the space is being marketed as a standalone apartment. Before you put down a deposit, ask for documentation. That's not distrust; it's the only thing that will help you later.
What to check before you rent or buy
1. Identify the unit. Ask for the padrón (property registry) number and, where applicable, the unit number or individual padrón. A numbered door is no proof that an approved dwelling exists behind it.
2. The approved plan. Ask for the construction plan or the horizontal-property (condominium) plan showing the unit, then compare layout, floor area, number of rooms, placement of bathroom and kitchen, openings and light wells, and the authorized use.
3. Square meters, properly explained. Ask point-blank which measurement the listing publishes: habitable, built, private, total, cadastral or clear interior area. If nobody can explain where the number comes from, don't treat it as verified.
4. Light and ventilation. During the showing: does the main room get natural light, what does the window face, does the opening actually open, does it look onto open space or an enclosed corridor, does the bathroom vent through a window or a real duct, and are there lingering odors or condensation?
5. Damp. This isn't always cosmetic; it can stem from leaks, plumbing failures, condensation or construction defects. Photograph the stains and ask whether there's a technical report. A fresh coat of paint before a showing hides the problem for exactly as long as it takes you to sign.
6. Basic services. Potable water, a kitchen sink, a bathroom with washbasin, shower or tub and a flushing toilet, working drains, safe electrical wiring and code-compliant hookups to the available utility networks.
7. Does the listing add up? Save screenshots of the ad, photos, messages and any claim made about square meters, bedrooms, gastos comunes (monthly building fees) or permits. If a discrepancy surfaces later, that's your evidence.
What to do if you suspect something's off
Start by asking for clarification in writing from the owner, building manager or agency: the plan and a precise identification of the unit, before you hand over any deposit.
If the property is in Montevideo:
- Construction or subdivision work believed to have been done without a permit can be reported through the unpermitted works or buildings filing, via your Centro Comunal Zonal (local municipal office).
- For serious damp, plumbing or structural problems, there's a technical inspection request.
In other departments, the question goes to the local Intendencia (departmental government): room dimensions, light wells, openings, ceiling heights and ventilation systems all vary.
If a professional provider published false information or left out essential details, article 24 of Ley 17.250 (Uruguay's consumer protection law) prohibits misleading advertising, and the Unidad de Defensa del Consumidor (the national consumer protection office) has a form for inquiries, claims and complaints — how far its authority reaches in rental matters depends on the role the agency or building manager played.
And an important warning if you've already signed: don't unilaterally stop paying rent or walk away from the unit without getting advice first. Building irregularities and the effects of your lease are related issues, but they're not resolved the same way, and going it alone can leave you worse off.
Frequently asked questions
Is the current minimum for a studio 25 m²?
Yes. As of August 1, 2026, article 18 of Ley 13.728 sets 25 m² of habitable floor area.
Has that minimum been in place since 1968?
No. The law dates from 1968, but the specific minimum for studios has applied only since 2022.
Is the 25 m² measured wall to wall?
No. The legal definition includes the bathroom, kitchen, circulation space, certain storage areas and wall thicknesses.
Does a room also have to be 25 m²?
No. That minimum applies to a complete studio dwelling.
Does every room need a window?
Bedrooms, living rooms, dining rooms and kitchens have to receive natural light. The specific requirements for openings, light wells and ventilation also depend on departmental regulations.
Can an interior bathroom be code-compliant?
Yes, if it has the ventilation system allowed locally. In Montevideo that can mean a code-compliant duct; the mere presence of an exhaust fan doesn't prove it.
Does the cadastral certificate confirm the dwelling is legal?
Not on its own. It's a useful reference, but regularity is established through plans, permits and departmental records.
Can a department allow less than 25 m²?
Ley 13.728 frames its specifications as minimums that regulations may raise. For a dwelling covered by that regime, they shouldn't be lowered.
How we can help
At INGAR we work to keep what we publish consistent with the documentation on file, and we don't market a room as if it were a standalone apartment.
If you're looking at a property and the square meters, the layout or the ventilation don't add up, send us the listing: we'll help you figure out what documentation to request before you commit to a deposit.
If you're weighing a specific studio, check its floor area against these minimums first, then look at the returns: our investment opportunities publish estimated yield, and our property listings let you filter by unit type.
Keep reading
- House, apartment, studio or building from scratch: how to decide
- What you need to rent in Montevideo
- Who holds your security deposit
- Gastos comunes: what they cover and how they're calculated
- How to spot a misleading real-estate listing
- Uruguay's rental law: rights and obligations
Sources
- Ley 13.728, article 17 — dwellings covered by the minimum housing standard
- Ley 13.728, article 18 — minimum housing standard
- Ley 13.728, article 19 — definition of habitable floor area
- Ley 19.996, article 228 — introduction of the minimum for studios
- Digesto Departamental of Montevideo, article D.3310 · habitable rooms · bathrooms
- Ley 17.250, article 24 — misleading advertising
- Parlamento — bill to amend article 18
General information current as of August 1, 2026. The legal status of any given unit depends on its records, permits, authorized use and departmental regulations. This is not a substitute for review by an architect, notary or attorney.