Propriedade horizontal in Portugal: requirements, steps, permilagem and costs to split a building or a house into separate units

Propriedade horizontal is the regime that lets the units of a building belong to different owners, as long as they can function as independent units (Civil Code article 1414). Each condómino (unit owner) is the sole owner of their unit and a co-owner of the common parts, such as the land, the structure, the roof, and the entrances and stairs in shared use (articles 1420 and 1421).

Only units that are independent, distinct and separated from each other, with their own exit to a common part of the building or to the street, can be frações autónomas (article 1415). If a legal requirement is missing, the deed is void and the building falls under co-ownership, with each co-owner keeping the share the deed gave them (article 1416).

Propriedade horizontal can be created by contract, adverse possession, administrative decision or court decision, in a partition action or in probate (article 1417). This guide covers the most common case: an owner who splits their building by contract before selling or dividing the units. The regime also applies to groups of adjoining buildings linked by common parts (article 1438-A).

Before you think about the deed, check that the building passes two tests: the civil one, under the Civil Code, and the administrative one, which the Câmara Municipal checks. In practice, each unit must meet the following:

• Independent unit: the unit serves its purpose on its own, whether a home, a shop, a garage or a storage room.
• Distinct and separated: walls and floors separate it from the others, with no required passage through another unit.
• Its own exit: it opens directly onto a common area, such as a lobby or a staircase, or onto the street.
• Same use as approved: if the deed states each unit's use, it must match the use in the design approved by the council, or the deed is void (article 1418(3)).
• Permitted work: if what exists does not match the approved plans, the council is unlikely to certify the units before you legalize the work.

The process starts in the council's archive and ends at the tax office (Finanças). This order avoids surprises:

• Gather the records: the online land registry certificate (certidão permanente), the caderneta predial (property tax record) and the council's building file, with the approved plans and the use title.
• Prepare the technical drawings: plans marking out each unit and the common parts, a schedule of areas and a proposed permilagem, usually drawn up by an architect or engineer.
• Ask the council for the certificate: the deed can only be signed with a council document proving that the units meet the legal requirements; for a building built to be sold as units, showing the approved design is enough (Notarial Code article 59).
• Sign the founding deed: as a public deed before a notary or as a private document authenticated by a lawyer, solicitador (a Portuguese legal professional), notary or registrar.
• Record it at the land registry: setting up propriedade horizontal must be registered, within two months, usually by whoever drew up the deed or authenticated the document (Land Registry Code articles 2 and 8-A to 8-C).
• Check the tax record at Finanças: each part that can be used independently is listed separately in the tax register, with its own taxable value (IMI Code article 12(3)); check that the units have been listed.

The founding deed (título constitutivo) is the document that creates the units. It must specify which parts of the building belong to each unit, so that each one is clearly identified, and set the relative value of each unit as a percentage or permilagem (per-mille share) of the building's total value (article 1418(1)). It can also state the use of each unit and of the common parts, include the condominium rules and provide for arbitration of disputes (paragraph 2), and it can give one unit exclusive use of common areas, such as a terrace or a yard (article 1421(3)).

There is no single legal template, but the deed should identify the building by its land registry description and tax record number and describe each unit by letter, floor, layout, area and permilagem. Since October 1, 2026, when an application is filed with a design, the architectural design already marks out the units and common parts and states each unit's relative value, with a drawing (Portaria 320/2026/1, annex V).

As for form, acts that create or change ownership of real estate are only valid as a public deed or an authenticated private document (Decree-Law 116/2008, article 22). The authenticated private document is the closest thing to an online process: whoever authenticates it must file it electronically on Predial Online the same day, because the authentication is not valid without that filing (article 24), and registration can then be requested online.

Permilagem is each unit's relative value expressed in thousandths of the building's total value; all the units add up to 1,000. It matters: unless otherwise agreed, the costs of the common parts are shared in proportion to the units' values (article 1424), each owner has as many votes at the owners' meeting as whole units in their permilagem (article 1430(2)), and several decisions need majorities based on the building's total value, such as two thirds for work that changes the building's architectural lines (article 1422(3)).

The law sets no formula. The usual method starts from each unit's area and weights it by factors that affect value, such as floor level, aspect, use and outdoor areas for exclusive use. The table shows a simplified calculation: multiply the area by the coefficient, add up the results and divide each share by the total.

Once set in the deed, permilagem only changes with the agreement of all owners, and a court cannot override a refusal when the change affects the units' relative values (article 1419(1) and (2)). It pays to get it right before the deed.

The cost has four parts. Only registration has a fixed national price; council fees are set in each municipality's fee schedule, and professional fees depend on the professional and on how complex the building is. For a building with three units, for example, registration costs €325.

The law only sets a deadline for registration: two months from the deed or the authentication. The council certificate has no specific deadline in the RJUE (Regime Jurídico da Urbanização e Edificação, Portugal's planning and building code) and depends on the file being complete and on the building matching what was approved; if the building is still due a use notice, the certificate request can be filed with it (RJUE article 66(3)). Ask for the certificate as soon as the drawings are ready, and book the deed only once you have it.

Splitting a moradia (detached or semi-detached house) into two or more units, for example the ground floor and the upper floor, is possible, but it rarely starts at the notary. A house licensed as a single-family home has one dwelling; for it to have two, each part must comply with Civil Code article 1415 and the use of the new homes must be covered by a title at the council. Under the RJUE, changing the number of dwellings is alteration work (article 2(d)).

The route depends on the work. If the split only needs interior work that does not change façades, roofs or heights and does not affect the structure, or affects it with a structural design and a signed statement of responsibility, the work is exempt from a permit (article 6(1)(b)), as explained in the guide to building work without a permit, and the use is covered by a prior notice with a waiting period (article 62-B). If you need a new street door, an outside staircase or an extension, you need a permit or prior notice and, at the end, a use notice (article 62-A). Before you start, check whether the PDM (Plano Diretor Municipal, the municipal master plan) and municipal regulations allow an extra dwelling there; a PIP (pedido de informação prévia, a formal planning inquiry) answers that in writing.

Two houses on the same plot, with shared access, garden or pool, can be placed under propriedade horizontal as a group of buildings (Civil Code article 1438-A). The alternative is to create separate plots, under the rules explained in the guide on destaque or subdivision.

Once in place, the deed can only be changed by public deed or authenticated private document, with the agreement of all owners (Civil Code article 1419(1)). The building manager can sign on behalf of the condominium if the agreement is recorded in minutes signed by everyone (paragraph 3). There are exceptions and specific rules for the most common cases:

• Common parts: a court can override a refusal if the owners who object hold less than 1/10 of the invested capital and the change does not affect the conditions of use, the relative value or the use of their units (article 1419(2)).
• Merging units: merging two or more adjoining units in the same building needs no approval from the other owners; for storage rooms and garages they do not even need to adjoin (article 1422-A(1) and (2)).
• Splitting a unit: only allowed if the deed permits it or the owners' meeting approves it with no objection; whoever merges or splits then amends the deed on their own and notifies the building manager within 10 days (article 1422-A(3) to (5)).
• Changing the use to housing: since January 1, 2024, turning a unit into a home needs no approval from the other owners, and the owner who handled the change with the council amends the deed themselves (article 1422-B).
• Council document: if the change alters the layout or use of the units, the deed can only be signed with a council document proving the legal requirements are met, unless there is an approved design for the conversion work (Notarial Code article 60).

Bring in a professional when the building has unpermitted work, when you want to split a house or a unit, or when you need a permilagem that will stand up to future buyers' scrutiny. Apto Group reviews the municipal file and recommends the right route through its change of use service.

Whatever your case, avoid the most frequent mistakes, which tend to surface late, at the council or on the day of the deed:

• Booking the deed before you have the council certificate, which must be attached to it.
• Splitting the building as it is today when it does not match the approved plans, because of unpermitted annexes, attics or enclosed balconies.
• Setting the permilagem by area alone, without weighting floors, terraces or yards, and then finding that changing it requires unanimity.
• Stating a use for a unit in the deed that differs from the approved design, which makes the deed void.
• Missing the two-month window to request registration, which doubles the fee.

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

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