What permits and licences does a prefab house need?

Does a prefab house need a permit? Yes, and the law names it

Yes, if it is going to be a home. Spain's national Land Law (article 11.4.c) requires express authorisation for “placing prefabricated houses and similar installations, whether temporary or permanent”, with negative silence: if the town hall does not reply, you have no permit.

Wheels do not get you off the hook either. In its ruling of 5 December 2024, the Supreme Court treated mobile homes as prefabricated houses rather than trailers, because they are made to be lived in, and required them to have a planning permit.

The building system does not matter: timber, concrete, steel, container or mobile home. If someone sells you a home that is “legal with no paperwork”, be wary.

What really decides: the land classification

Before ordering anything, find out what class of land your plot is and what use the local plan gives it. The town hall has to tell you in writing if you ask (article 5.d of the Land Law), under whatever name it uses: cédula urbanística, planning report or certificate of compatibility.

• •Urban land: the easy case, if the plan gives it residential use and the house meets site coverage, height and distances to the boundaries.
• •Land zoned for development: it can be built on once the sector is urbanised.
• •Rural land: a home is the exception.

Be wary of a “suspiciously cheap” plot: it is often rural land. What to check, document by document, is in land for a prefab house.

The permits for a prefab house, step by step

On urban land, a prefab house follows the path of any other build, and each document opens the next:

1. 1Planning information: whether the house fits and within what limits.
2. 2A project by an architect stamped by their professional association, compulsory for a home.
3. 3Building permit: without it, work cannot start.
4. 4Certificate of completion.
5. 5First occupancy (permit, habitability certificate or responsible declaration, depending on the region): without it there are no permanent utility connections.
6. 6New construction deed before a notary, Land Registry and Cadastre.

A new home requires an express permit: the responsible declaration used for small jobs is not enough. The full sequence, with what you pay at each step, is in a prefab house step by step.

On rural land: the exception, not the rule

The short answer is no. The Land Law assigns rural land to agricultural, livestock, forestry and similar uses (article 13.1); anything else is an exception, under each region's conditions. For example:

• •A home tied to a genuine farming or livestock operation.
• •Authorised rural tourism.
• •A detached home on a minimum plot size, where the regional law allows it.

Installing it “to see if nobody notices” is expensive: a fine and a demolition order at your cost. Registering your address there does not make it legal, because the municipal register says where you live, not whether the house is legal. And without a permit you cannot record it in a deed as a home, which complicates a mortgage for a prefab house.

What the permits cost and how long they take

They are calculated on the material construction budget (PEM), not on the sale price, and each town hall sets its own rates:

• •ICIO, the construction tax: it has a legal ceiling (4% of the PEM) and is due when work starts, with or without a permit.
• •Permit fee: set by the local bylaw, it usually stays below 1.5% of the PEM.
• •On a PEM of €100,000, the maximum ICIO is €4,000, plus the fee.

There is no single deadline in Spain: each region sets it and, if not, it is 3 months. In practice, from a month and a half to four months, and the clock stops if you are asked to correct documents. Add it to the factory time in how long a modular house takes.

Will the manufacturer handle the permit for you? Rarely

Turnkey does not mean permit included. Among the houses with a turnkey price (189):

• •Few include it (41), and they come from 6 brands: it depends on who you buy from, not on what you negotiate.
• •Some warn that it is extra (32). American Building System, in its 2025 price list, charged it together with the project at €100 per built square metre.
• •Many say nothing (78), and if it is not in writing, assume it is not included.

It is included, for example, in Zero Housing's ZH 102 (in Spanish), MasArea Modular's Estocolmo (in Spanish) and Casas Cube's Cube 100 (in Spanish). And even when included, sometimes it is only the paperwork and not the fees: ask in writing what is covered.

Watch out: the rules change by region and municipality

There is no “prefab house law”: each region has its own land law and each town hall its own general plan. Three examples for rural land (check them against the version in force):

• •Galicia: only a home tied to a farming or livestock operation (article 35 of Law 2/2016); a house on its own goes in the rural settlements.
• •Andalusia: the LISTA (Law 7/2021) allows a detached home as an extraordinary action, with prior authorisation and without creating a new settlement.
• •Valencian Community: a plot of at least one hectare and a maximum coverage of 2%, that is, about 200 m² of footprint per hectare (article 211 of its planning law).

If you already know where, see prefab houses in Galicia (in Spanish), Málaga or Valencia (in Spanish), or compare manufacturers.