What does obras de alteração mean in Portugal?
Obras de alteração change the physical or aesthetic features of an existing building, such as the structure, the number of dwellings, the interior layout or the type and colour of exterior finishes, without adding area, footprint or height.
- Rests on
- RJUE, art. 2.º d), art. 6.º n.º 1 b)
- Law
- Decreto-Lei n.º 555/99 (RJUE), as republished by Decreto-Lei n.º 108/2026
- Version
- In force since 1 October 2026 (Decreto-Lei n.º 155-B/2026)
- Official text
- data.dre.pt/eli/dec-lei/108/2026/05/29/p/dre/pt/pdf
- Sources
- data.dre.pt/eli/dec-lei/108/2026/05/29/p/dre/pt/pdf
data.dre.pt/eli/dec-lei/155-b/2026/07/31/p/dre/pt/pdf
data.dre.pt/eli/declretif/29-a/2026/07/27/p/dre/pt/pdf - Checked
- 2026-11-05
What it means for the owner
- Interior alterations are exempt from licence and notification if they have no exterior impact and do not affect stability (art. 6.º n.º 1 b)).
- If they do touch stability, they need a stability project and a termo de responsabilidade, with a seismic reinforcement project where required, filed with the start-of-works notice (art. 6.º n.º 1 b) ii)).
- Replacing window frames by more efficient ones of the same geometry and finish counts as minor works (art. 6.º-A n.º 1 j)).
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