House extension: do you need a permit in Portugal?

Independent site: we are not a public authority, and this is not legal or tax advice.

A house extension (ampliação) needs a licence. Prior communication is enough only where a detail plan, subdivision or execution unit sets the details, or in a consolidated urban zone with no taller result than the usual facade height and no cessions.

Ask for a free check

Answer

Licence

Prior communication instead

Prior communication replaces the licence only where a detail plan, execution unit or subdivision already sets the details, or in a consolidated urban zone with no cessions and a height no taller than the most common facade height on that stretch of street.

Extension means

Works that increase the footprint, total floor area, facade height, or height or volume of a building (art 2(e))

Very small additions

A structure of up to 2.2 m high and 10 m² that does not face the public road is a minor work and exempt (art 6-A(1)(a))

Council rules

Your council can add detail in its own building regulation where the law lets it, so ask before you start.

Legal basis

RJUE art 2(e), 4(2)(c) and 4(4)(d) and (e), RJUE (Decreto-Lei 555/99) as republished in the Annex of Decreto-Lei 108/2026

Sources

data.dre.pt/eli/dec-lei/108/2026/05/29/p/dre/pt/pdf

Checked

2026-11-05