Areas and physical characteristics
Área bruta privativa (gross private area)
The surface of the unit or building measured along the outer perimeter of its walls and the axes of the walls separating units, including enclosed private balconies and basements or attics used in the same way as the unit. It is the main area recorded in the caderneta predial and the one with the greatest weight in the calculation of the taxable asset value (VPT).
In practice: the area in the caderneta often differs from the areas shown in listings, plans or the energy certificate. Each document measures different things under different rules. In a sale, the caderneta area is the property's tax and registry reference.
The area in my caderneta is wrong. What now?
Discrepancies are corrected with the Tax Authority, usually based on the municipal licensing file. Deal with it before going to market: it affects documents, the buyer's financing and the deed.
Área bruta dependente (gross dependent area)
Covered areas of the property with private use but a purpose ancillary to the main one: garages, parking spaces, storage rooms, attics or basements unfit for habitation, enclosed balconies and covered terraces. It appears in the caderneta predial in its own field, separate from the gross private area.
In practice: in the VPT calculation, dependent area carries a reduced weight compared with private area, which is why two properties with the same total area can have very different VPTs. It is also where outdated records appear most: parking spaces bought later, storage rooms never registered, annexes built afterwards.
Does the garage count towards my apartment's area?
It depends on the document. In the caderneta it appears as gross dependent area (or as its own autonomous unit, if separately registered), not added to the gross private area.
Área bruta de construção (gross construction area)
The sum of the areas of all floors of a building, above and below ground, measured along the outer perimeter of the walls. It is the reference area in urban licensing and building parameters.
In practice: this is the area that matters when discussing a plot's building potential or a house extension, because municipal plans and subdivision permits refer to it. It should not be confused with the caderneta's gross private area, which serves tax purposes.
Which area tells me how much I can build?
The permissible gross construction area, resulting from the building index applicable to the plot and the other rules of the plan or permit.
Área útil (net usable area, RGEU)
The sum of the areas of all rooms in a dwelling, including hallways, internal circulation, bathrooms and storage, measured along the inner perimeter of the walls enclosing the dwelling and deducting internal partitions. Defined in the national building regulations (RGEU) and stated in the housing technical file.
In practice: because it deducts every wall, the net usable area is always smaller than the gross private area. In typical apartments the difference often runs to 10-20%. It is the measure that best reflects the space you can actually use.
Why is the net area smaller than the caderneta area?
Because it measures only the inside of the rooms, without walls. The caderneta measures along the outside and includes them.
Área útil de pavimento (net floor area, energy certificate)
The area used in the energy certification system: the sum of the usable interior spaces, measured in plan along the inner perimeter of the external walls, including internal partition walls. It is the area shown on the energy certificate.
In practice: because it includes partitions, it almost always gives a higher figure than the RGEU net usable area, and a different one from the caderneta. Hence a classic confusion when owners and buyers compare documents of the same property: three documents, three areas, none of them wrong.
The certificate says 120 m² and the technical file says 105 m². Which is right?
Both. They measure different areas under different rules: the certificate uses net floor area, the technical file uses the RGEU net usable area.
Área habitável (habitable area)
The sum of the areas of the rooms intended for living proper (bedrooms, living rooms and kitchen), excluding hallways, circulation, bathrooms and storage. Defined in the RGEU.
In practice: it is the narrowest of a dwelling's areas and rarely appears in everyday documents, but it is useful when comparing homes with very different layouts. Two dwellings with the same net usable area can have different habitable areas depending on how much space corridors and service zones take.
Where do I find my property's habitable area?
It usually does not appear in the standard documents. It is worked out from the plans by adding up the living rooms and bedrooms.
Área de implantação (footprint area)
The ground area occupied by the building, bounded by the outer perimeter of the external walls at ground level.
In practice: a central figure for houses and plots. Municipal plans frequently set footprint indexes and limits, and the difference between the existing footprint and the permissible one shows the potential for ground-level extension.
Does the footprint include the garden?
No. Only the ground covered by construction; the remaining free land is the logradouro.
Área de terreno (plot area)
The total surface of the property, including the area covered by construction and the uncovered area, as recorded in the caderneta predial and the land registry description.
In practice: in houses it is common for the caderneta's plot area to differ from the land registry certificate or the cadastral reality. Old inheritances, corrections never made and imprecise boundaries accumulate over decades. Significant discrepancies between documents should be addressed well before a sale.
The caderneta and the registry show different plot areas. Is it serious?
It is a discrepancy worth correcting. The harmonisation route depends on which documents support each figure.
Logradouro (private open grounds)
The free land area of an urban property, adjacent to the construction, serving a complementary use: garden, yard, patio or access.
In practice: the logradouro belongs to the property and counts towards the plot area, but it is not construction area. In buildings under the horizontal property regime it may be a common part or be assigned to the exclusive use of a given unit, depending on the constitutive title. The distinction has real consequences for value and use.
Is the yard mine or the building's?
It depends on the constitutive title of the horizontal property. It may be a common part, a common part for your unit's exclusive use, or part of the unit itself.
€/m² (price per square metre)
An indicator obtained by dividing a property's value by the number of square metres of a given area of that property. The result varies with the area used.
In practice: the same property has as many €/m² figures as its documents have areas. Calculated on the gross private area it gives one number; on the net usable area, another, higher one. Comparisons between properties are only valid when made on the same type of area, which listings rarely do.
Which €/m² should I use to compare properties?
Whichever is calculated consistently on the same type of area across all the properties compared. Consistency matters more than the choice of area.
Tipologia (typology: T0, T1, T2...)
The classification of dwellings by the letter T followed by the number of bedrooms: a T3 has three bedrooms, whatever the other rooms. The older count by "assoalhadas" adds bedrooms and living rooms together.
In practice: the property's formal typology is the one in the approved municipal project, not everyday use. An office made out of a bedroom, or a bedroom gained by splitting a living room, does not change the documented typology. Differences between what is advertised and what is licensed surface in a sale's document review.
Can I advertise a T3 with a divided living room as a T4?
The documented typology remains that of the approved project. Presenting the property at odds with its documents creates predictable problems in the sale.
Pé-direito (ceiling height)
The clear height measured between the floor and the ceiling of a room. The RGEU sets minimums: 2.70 m for habitable rooms and 2.40 m (2.20 m accepted in certain cases) for hallways, corridors, bathrooms and storage.
In practice: ceiling height is decisive for the legal habitability of attics, basements and annexes. Spaces below the minimum cannot be licensed as habitation, even if used as such. It is one of the points checked when studying whether converted areas can be regularised.
My attic has 2.20 m. Can it be a bedroom?
As a habitable room it does not meet the regulatory minimum. Other uses may be possible, depending on the case and the municipality's position.
Exposição solar (solar orientation)
The orientation of the property's façades and openings relative to the cardinal points, determining the natural light each room receives through the day.
In practice: in Portugal, south-facing is the most sought after, with sun through the day and better thermal behaviour. Orientation influences the property's energy performance and, measurably, perceived value: among identical units in the same building, orientation often explains differences in demand.
Which orientation is best?
South for the living areas is the classic reference. East favours mornings, west favours afternoons, and north gives steady light without direct sun.
Polígono de implantação (buildable footprint)
The delimitation, in a subdivision permit or planning instrument, of the area of the plot within which building is permitted. It differs from the footprint area, which is what is actually built.
In practice: on plots with existing construction, comparing the buildable footprint with the actual footprint shows whether there is room to extend at ground level, and where. Constructions outside the buildable footprint, even old ones, are planning non-conformities.
Where do I check my plot's buildable footprint?
In the subdivision permit, where one exists, or in the applicable planning instruments, at the municipal services.

