First or second occupancy? Why the town hall can declare your declaración responsable invalid

October 2026

There is a widespread idea: “the house already exists, it was already lived in, so I only need the second occupancy”. Sometimes that is true. But if the house has grown since occupancy was last granted, the town hall can say it is no longer the same dwelling, and then the declaration you submitted is no good.

We explain it through a real case we handled recently, without names, because it shows very clearly how it works.

First and second occupancy: the difference

Decreto 12/2021 distinguishes between the two. There is first occupancy when (article 3):

A new home is completed.
A renovation, extension or refurbishment produces an essential modification compared with the conditions under which the previous occupancy was granted.
A commercial unit or other building becomes a home.

In all other cases, the home is still the same and what applies is the second occupancy, which is a simpler procedure and one we talk about in Second occupancy to connect electricity and water.

The decree does not define precisely what an “essential modification” is, and that leaves the town hall room for interpretation. In practice, increasing the built floor area, adding new structures on the plot or significantly changing the layout are usually considered essential. Painting, changing the flooring or renovating the bathroom are not.

The case: a house with a pool and a storeroom

A detached house with a plot needed its occupancy licence in order to complete a mortgage. The house had a permit from years ago. A second occupancy declaration was submitted and, weeks later, the town hall declared it ineffective.

How did they know? By comparing the orthophotos, the aerial photos the Instituto Cartográfico Valenciano publishes year by year. Images from several consecutive years showed a pool appearing and an old storeroom being rebuilt. Neither of the two works had a permit. On that basis, the town hall considered that the home had undergone an essential modification and that a first occupancy was required, which could not be granted while there were unlegalised works.

How it was resolved

We were commissioned to handle the legalisation of the pool and the storeroom. These were the steps:

Review the documentation: original permit, title deeds, Cadastre and the town hall's decision.
Visit and measure what had been built, and check that it complied with the planning rules: site coverage, distances to boundaries, heights. Had it not complied, it could not have been legalised.
Request the planning information from the town hall in advance, which in this municipality was a requirement that appeared halfway through the process.
Draw up the legalisation project, with the certificate of completed works required by the Architects' Association, and get it endorsed (visado).
Obtain the legalisation permit and, with it, resubmit the occupancy application for the home.
With the occupancy in order, the mortgage could finally be signed.

It took longer than anyone wanted, and cost money nobody had budgeted for. But it could be solved. What has no easy solution is buying without knowing and finding out when the bank is already waiting.

If your declaration is declared ineffective

The decision must state its reasons: it has to say why. You then have two options:

Fix the problem: legalise whatever is missing or, if the town hall has made a mistake, provide the documents that prove it (dated photos, old permits, certificates of building age).
Appeal: an appeal for reconsideration (recurso de reposición) to the town hall itself within one month, or go straight to a contentious-administrative appeal within two months. For this it is advisable to have a lawyer.

Often the quickest route is the first. Arguing about what can be seen in an aerial photo is usually difficult.

What if the works are very old?

In the Valencian Community, the town hall has 15 years from the completion of unlicensed works to order that legality be restored (article 255 of the TRLOTUP). After that period it can no longer force demolition, but the works do not become legal: they are left in a situation where, in general, only maintenance works are allowed, not extensions.

There are important exceptions: on non-developable land, in green spaces, roads or protected assets, the current law sets no time limit. For older works you need to check which law was in force when they were completed, but an unlicensed pool at a country house may end up having to be demolished even if it is years old.

That is why sometimes the solution is not to legalise but to prove the building's age with a certificate, and other times it is the other way round. It depends on the land classification, the dates and what the local plan says.

How to avoid it

Before buying, compare the house with its permit and with the Cadastre. Anything that does not appear in either of them is suspicious.
Look at the orthophotos from different years on the Generalitat's map viewer. You can also see when each thing appeared.
If there are unlicensed works, decide before signing who will legalise them and who will pay for it.
Do not submit a second occupancy “to see if it gets through”. If the technician knows about the problem, they should tell you.

If you are buying a house with a plot in the Vega Baja, Elche, Alicante or the Vinalopó, a feasibility study tells you all this before you sign. And if you have already received a decision, write to us from the contact page. More information in legalisation of unlicensed works y first occupancy licence.