Legalizing an old house and annexes in Portugal: pre-1951 homes, habitation licenses and outbuildings

An old house, a house without a habitation license and an unpermitted annex are different situations with different solutions. The table sums up the starting point for each; the legalization procedure itself is covered in our guide to how building legalization works.

The municipal habitation license was made general by the RGEU, approved by Decree-Law 38382 of August 7, 1951. Its article 8 required a habitation license for new, rebuilt, extended or altered buildings. Buildings constructed before then were not subject to the RGEU license, so it is normal for them not to have one; in cities with older municipal rules, check with the council whether some other requirement applied. The legal basis is not article 5 of the RJUE (Portugal's planning and building code), which deals with which authority is competent, despite what you may read.

There is an important nuance for country houses. Article 1 of the RGEU applied it to the urban and protection zones of municipal seats and of other towns with an urban plan; elsewhere, it only applied once the municipality extended it by its own decision. So in many rural areas the duty to obtain a license began after 1951, and a house built later may also never have needed one. The date that matters is when the RGEU began to apply in that place, which you should confirm with the Câmara Municipal (city council).

Since October 1, 2026, the RJUE addresses these houses directly: a building's last valid legal status includes work that needed no permit when it was carried out. This does not cover later work. If the house was extended or altered without a permit after the RGEU applied in the area, that work may need to be legalized, even though the original core is lawful.

In Porto, the council issues a “certificação de que uma construção é anterior a 1951” (certificate that a building predates 1951), requested through the certificates service on the Portal do Munícipe, with a stated average response time of 30 working days. In other municipalities, including Lisbon, the name and procedure vary (certidão de isenção de licença de utilização, certidão de construção anterior a 1951); check the local regulation and ask at the council.

Since 2024, this certificate is no longer required to sign the deed, but it is still useful evidence for buyers, banks and the council itself. These are the kinds of evidence commonly used; confirm with the council which ones it accepts:

• The caderneta predial (property tax record) and tax history, especially if the property was registered for tax long ago (the registration date is an indication, not conclusive proof of the construction date).
• Old aerial photos and maps that already show the building.
• Old land registry descriptions, deeds, partitions or inheritance documents that mention the house.
• Plans, files or references in the municipal archive.
• Building features a professional can date, such as stone masonry and traditional roofs, always as supporting evidence.

If the house was built when the RGEU already applied in the area, it should have had a building permit and a habitation license or use permit. Start by asking the council for the property's file. It is common to find the building permit but no habitation license, because the process was never completed; in that case, the fix may just be the use notice, if what was built matches what was approved.

If there is no permit at all, or what was built differs from what was approved, you need to legalize. The procedure, the documents, the technical waiver for older buildings and the fines are explained in our guide to building legalization. Before concluding that a house is illegal, check whether it might predate the RGEU in that area, especially in rural Portugal.

Since October 1, 2026, under Decree-Law 108/2026, councils no longer issue habitation licenses or use permits. Legal references to those documents are now read as the notices in the table. Licenses and permits issued before remain valid as the use title and pass with the property.

In practice, “getting the habitation license” for an existing house now means filing one of these notices with the council, together with the professionals' statements of responsibility. The council only inspects the building when there are serious signs that it is not fit for the intended use.

Many annexes never needed a permit. Article 6-A of the RJUE treats the following, among others, as minor works exempt from prior control:

These exemptions do not apply to listed buildings or buildings being listed, or to their protection zones, and the municipal regulation may add or limit cases. Being exempt does not free the work from complying with the PDM (Plano Diretor Municipal, the municipal master plan), setbacks and all other rules. If the work is exempt, you can update the land registry description with a declaration of minor works.

An annex that exceeds these limits, borders a public road or was built in breach of the rules must be legalized. The council mainly checks the footprint and floor area allowed by the PDM, the setbacks from the plot boundaries and the height. If the annex exceeds what the plan allows, legalization may require making it smaller.

• Buildings, attached to the main building or not, up to 2.2 m high (or up to the ground-floor height of the main building) and up to 10 m², that do not border a public road.
• Boundary walls up to 1.8 m high that do not border a public road, and retaining walls up to 2 m.
• Garden greenhouses under 3 m high and up to 20 m².
• Solar panels and play or leisure equipment smaller than the main building.
• Other works defined in the municipal regulation.

Converting an annex into a home is a change of use. With no works, or only exempt works, it is filed as a comunicação prévia com prazo; with works, it needs a license or a comunicação prévia, depending on the case. Either way, the PDM must allow residential use and often an additional dwelling on the plot, and the space must meet the RGEU's habitability rules, such as minimum areas, ceiling height, natural light and ventilation.

If the annex never had a permit, the usual order is to legalize it and handle the change of use in the same application or right after. Before investing, a prior information request (PIP) can test whether the conversion is feasible, and our change of use service helps confirm the planning position. On rustic land the rules are stricter; see what you can build on rustic land.

Between January 1, 2024 and September 30, 2026, the Simplex reform stopped requiring the habitation license to be shown at the deed; it was enough to warn the buyer. Since October 1, 2026, the deed must state that the planning title was shown, or that the seller declares having one, or that the seller declares not having one; otherwise the sale can be annulled. A pre-RGEU house can be sold, and the certificate or evidence of the date helps the seller make that declaration with confidence.

If you are buying, do not rely on the seller's declaration alone. Before the promissory contract (contrato-promessa), check:

• The property's municipal file, or proof that it predates the RGEU in that area.
• Whether the current floor area and layout match the approved plans or the original core.
• Whether any annexes fall within the limits for exempt works or need legalizing.
• Whether your bank will finance the property with the documents it has.

There is no set price. The cost depends on whether a municipal file exists, how much floor area must be legalized and whether corrective works are needed. The usual items are the certificate or evidence of the construction date, the survey, the architectural design, any engineering designs the council requires, statements of responsibility, municipal fees and, where applicable, planning compensation.

Fees are set in each municipality's regulation and fee schedule; check them before you apply. A pre-RGEU house with no later work may only need evidence of the date, while an unpermitted extension requires a full application. An initial review of the municipal file tells you which case you are in before you spend on design; Apto Group does this through our building legalization service. If you plan to run the house as a short-term rental, see also what to check before registering an AL.

The official sources are in Portuguese. Check the version in force before preparing a notice, project or application.

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