How many houses can be built on a 5,000 m² plot?

Quick answer: the law does not set a number of houses. It sets a purpose. Article 55 of the General Urban Planning and Construction Act prohibits putting up buildings outside the urban boundary, except for three exceptions, and one of them is housing for the owner of the property and their workers, in the plural. That is why the right question is not how many houses fit, but who they serve and whether the group of buildings reads as working the property or as a disguised condominium. Two houses for the owner and their caretaker pass. Two identical houses for two families who bought jointly do not.

The plan sounds reasonable: two siblings buying a 5,000 metre plot together, or one of them buying it and putting up a house for their parents at the back of the property. The costs are split and everyone wins. The problem shows up at the Municipal Building Department, when it is time to apply for the permit.

What article 55 says, in its own words

Let us start by correcting a widely repeated idea. People often say that only one house can be built on a plot. That is not what the law says.

Article 55 of the General Urban Planning and Construction Act establishes that outside urban boundaries it is not permitted to open streets, subdivide to form settlements or put up buildings. That is the rule. Then come the exceptions, and there are three:

Which is why the honest answer to how many houses can be built is not a number. The law does not give one. What it gives is a purpose, and the permit turns on whether the project fits that purpose.

The real dividing line: when it stops being housing and becomes a development

This is the criterion almost nobody explains, and it is what decides the outcome at the counter.

Circular DDU 455 of the Ministry of Housing and Urban Planning, dated 18 January 2021, clarified that housing for the owner and their workers does not require a favourable report from the Servicio Agrícola y Ganadero (the Agriculture and Livestock Service, or SAG) or from the regional office of the Ministry of Housing, and is also not subject to article 2.2.4 bis of the General Ordinance, provided the construction does not amount to a development.

And a development, in the language of the Ordinance, is the full set of documentation for a building, including plans, reports and technical specifications. In other words, the distinction is not between one house and two houses: it is between building the housing the property needs and developing a group of buildings.

In practice. A main house plus a modest home for whoever looks after the property is processed as a building covered by the exception, and the Municipal Building Department only checks compliance with planning rules. Two equivalent houses, with separate access, independent meters and an internal boundary, read as a housing development, and that is when the sectoral reports the exception avoided get triggered.

Case law has backed this reading. The Supreme Court, in case No. 62.948 of 2020, held that when what is built on subdivided rural land amounts to a development, the favourable sectoral reports can be required, even if the owner's housing exception is invoked.

Why the land's designated use governs everything else

A 5,000 metre plot is not a residential lot. It is rural land designated for agricultural, livestock or forestry use, and decree law 3.516 requires that designation to be preserved after subdivision, prohibiting the formation of urban settlements outside territorial planning.

That is why the same design can be approved or rejected depending on what the file shows. If the two houses are presented as part of working the property, one reading applies. If the layout has the geometry, access points and infrastructure of a small condominium, another reading applies, and it matches what the SAG looks at when it reviews subdivisions, a subject we cover in why the Service rejects subdivisions.

What the Municipal Building Department looks at in a two house project

• Hierarchy between the buildings. The worker's home must read as such: its size, finishes and layout need to match. Two houses of equal size and standard contradict that story.
• One property, one roll number. Both homes fall under the same property tax roll number. There is no way to get separate roll numbers without subdividing, and subdividing under 5,000 metres is not allowed except under a legal exception.
• Access and infrastructure. Two independent entrances from the public road, with an internal fence separating the two houses, is the clearest sign of two self contained units.
• Utilities. Utility companies require their own roll number and final municipal approval for an independent connection. With a single roll number only one meter is installed, and the second house's consumption is split with a private submeter, which has no standing with the utility company.
• Consistency with what is already built. If the property has no productive buildings at all and does have two houses, the agricultural purpose is left unsupported.

The routes that do exist, depending on what you want to achieve

What happens if you build anyway, without a permit

This is the most expensive path, and the consequences cascade.

• Without a permit there is no final municipal approval, and without final municipal approval the building does not exist for legal purposes. You can try to regularise it later under the ley del mono, but that route assumes the building is one that could be authorised on that land, which is precisely what is in question.
• Fines and possible demolition. The Municipal Building Department can refer the infringement to the Local Police Court, and in serious cases order the demolition of what was built in breach of the rules. How much you risk and how to defend against that fine is covered in Municipal Building Department fines for building without a permit.
• The property stops being financeable. No bank will take a plot with an unauthorised second home as collateral, and without final municipal approval a sale with a mortgage falls through.
• The family conflict gets registered. If two people built on a single roll number, neither can sell their house separately. It is a single property, and any of the co owners can request partition of the whole property.

The mistake of buying jointly without resolving this first

It is worth pausing on the most common case, because the damage is not a planning issue but a financial one.

Two people buy a plot and each builds their own house. On paper, they are co owners of the whole property, not owners of their own house. Neither can sell their part separately, neither can mortgage it, and if one of them dies their heirs enter the co ownership. And if one of them requests partition, since the property cannot be divided into two lots under 5,000 metres, the judge's solution is for one to buy out the other, or for the whole property to be auctioned.

The house you built does not give you the right to keep it: it gives you a credit for improvements within that same court proceeding. That is why the correct order is the opposite of how it is usually done: first you establish whether the property allows two separate properties, and only then do you buy.

Frequently asked questions

Can I subdivide my 5,000 metre plot into two of 2,500?

Not through the ordinary route. The minimum under decree law 3.516 is 5,000 metres per lot, and it does not allow an exception by agreement between the parties. The only way to go below that area is a legal exception, and the most commonly used one is the ley Sabag, which requires the transfer to be to a direct relative. The rest are set out in the exceptions for subdividing below half a hectare.

So how many houses can I build?

As many as correspond to the housing of the owner and of their workers, based on the actual use of the property. There is no figure in the law. What there is, is a functional limit: once the group of buildings stops reading as living on the property and starts reading as a housing development, it falls outside the exception.

Can I install two independent meters?

For an independent connection, utility companies require their own roll number, registered title and final municipal approval. With a single roll number, only one meter is issued. What is used in practice is an internal submeter to split the consumption, which works between the parties but creates no relationship with the utility company and proves nothing to the municipality.

We bought as shares and rights. Does that change anything?

Not for permit purposes. Buying fifty percent of the property does not entitle you to build a second main house, because the restriction is a planning one and does not depend on how many owners are named in the title. And in financial terms the situation is worse, not better: we cover that in the guide to shares and rights in an undivided estate.

Is there a maximum size for the caretaker's house?

The law does not set a size in metres. What gets assessed is consistency: a worker's home with the size and standard of a main house contradicts its own classification. In practice, the proportion between the two buildings is one of the factors that carries the most weight.

Can I build first and regularise later?

It is the most expensive gamble. Later regularisation assumes that what was built is one that could be authorised on that land under the applicable rules. If the second home does not fit the exception, no procedure will make it legal, and in the meantime the whole property is left without final municipal approval.

What if, instead of a second house, I extend the first one?

It is a real alternative and often the simplest one, as long as the result is still a single home and not two self contained units in disguise. An extension with its own kitchen, access and utilities is, in effect, a second home, and gets assessed as one.

How we handle it

The first step is a feasibility review before the first stone is laid: what the municipality's certificate of prior information says, what use the land is designated for, what area the property actually has, and whether it can accommodate a second unit. That tells you whether the project should go through the article 55 exception, the ley Sabag, or a formal subdivision.

Next comes designing the file, which is where the permit is won or lost: the hierarchy between the buildings, the access points, the justification for the property's use and the submission to the Municipal Building Department. Our own team of surveyors and architects does the survey and the plans, so the project and the legal file are put together at the same time, not in separate offices.

If the purchase is between two or more people, before signing it is worth looking at the title study and putting in writing what happens if the property later cannot be divided. And if the problem already exists, with an unpermitted building or a co ownership at a standstill, there is regularisation of title and the civil litigation route, depending on the case.

Send us the property's roll number and tell us what you want to build and for whom. With that, we can tell you whether your case falls within the exception, what can be submitted, and what is worth changing before you spend money on plans.