Painting and damp in Porto: rain, azulejo tiles and two deadlines for scaffolding
Porto gets 1,147 mm of rain a year on 105 rain days (IPMA), and 52% of its buildings date from before 1961 (INE). Changing a facade colour is exempt from prior control, but the Portal do Munícipe gives two different deadlines for scaffolding: 20 and 30 working days.
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The walls of Porto
Porto has 39,303 buildings in the INE 2021 Census. These are whole buildings, not flats, and the repair need is the opinion of the person who answered the census. 13.3% date from before 1919 (4.9% nationally) and 52.2% from before 1961 (23.1% nationally). Only 9.7% are from 2001 onwards. 5.4% need deep repair, against 4.6% nationally, and 43.4% need some repair (35.8% nationally).
In the photo on this page, a building in the centre has a facade covered in azulejo tiles, with granite around the windows and on the corners. Tiles and granite are not painted like plaster: both first call for finding out where the water comes from. We found no source on which wall material is most common in Porto’s older houses, so we give no percentages here.
The Historic Centre of Oporto, the Luiz I Bridge and the Monastery of Serra do Pilar have been on the UNESCO World Heritage list since 1996. For anyone who wants to paint, what matters is what the council’s Regulatory Code says about colour, tiles and buildings of heritage value, below.
SourcesIPMA, climate normal Porto / Pedras Rubras 1991-2020 (read 3 November 2026) · Regulatory Code of the Municipality of Porto, November 2025 version (articles B-1/2, B-1/31, D-1/33-B and D-1/33-C) · Portal do Munícipe: occupation of public space for works (read 3 November 2026) · Portal do Munícipe: notice of start of urban works (read 3 November 2026) · Decree-Law 108/2026 of 29 May (consolidated RJUE), copy from the Order of Architects · UNESCO, Historic Centre of Oporto, Luiz I Bridge and Monastery of Serra do Pilar (read 3 November 2026) · INE, 2021 Census (0011482)
The buildings of Porto
39,303 buildings counted in 2021
- 90.3% built up to 2000 (country: 82.1%)
- 52.2% built before 1961 (country: 23.1%)
- 5.4% with deep repair needs (country: 4.6%)
The vertical mark on each bar is the share for the whole country.
Source: INE (Statistics Portugal), Census 2021, indicator 0011482, updated 12/11/2022. CC BY licence. The figures are for whole buildings. An old building can be well kept and a new one can have damp. Age is a hint, not a diagnosis.
Rain, damp and cold in Porto
The nearest IPMA station in the 1991-2020 normals list is Porto / Pedras Rubras (no. 545, 67.7 m altitude, 41.23 N). It lies north of the city, so it is a reference and not a measurement from the Ribeira. IPMA describes the series as hybrid.
Average rainfall is 1,146.9 mm a year, with peaks in November (165.9 mm), December (153.3), January (151.0) and October (148.9), and only 16.6 mm in July. There are 105.4 days a year with 1 mm or more and 38.8 with 10 mm or more. The mean annual temperature is 15.3 °C. The minimum drops below 0 °C on 1.4 days a year. The file has no air humidity, so we give no figure for it.
What this means for painting: from October to January there are weeks of heavy rain, and a wall facing north, or one that takes run-off from the roof, dries slowly. Read the drying times on the paint data sheet and do not paint a damp wall. Frost hardly matters; rain does.
Houses and walls in Porto
Historic centre
In the historic centre, listed by UNESCO since 1996, facades have their own rules: the Regulatory Code forbids colour changes that harm historic groups of buildings, and removing tiles depends on the law that protects azulejo heritage. Check colour and material before asking for quotes.
Old apartment blocks
In 52.2% of Porto’s buildings (INE, 2021 Census) construction dates from before 1961. In this kind of building, tiles or old render on the facade and thick stone walls are common (general rule, not confirmed for Porto). A stain on an interior wall may come from the facade, the roof or ground water.
Recent blocks
Only 9.7% of Porto’s buildings are from 2001 onwards (INE). In these newer blocks the usual problem is not ground water but condensation in closed bedrooms and bathrooms without ventilation, seen as mould in corners and behind furniture (general rule).
Rules and permits in Porto
Facades. The Regulatory Code of the Municipality of Porto (November 2025 version), article B-1/31, paragraph 1(s), treats as works of minor urban relevance, exempt from prior control, changing the colour and replacing the exterior cladding of facades, without prejudice to the law protecting azulejo heritage and provided the cladding is not inventoried pastilha tiling of high heritage value. Paragraph 3 forbids these works if they do not fit the architecture of the building or, through colour or material, harm historic or artistic groups and places. Paragraph 5 says that in buildings inventoried in the PDM as Buildings of Heritage Value, all these works need a licence or prior notice. Article B-1/2, paragraph 6, requires the palette of the Colour Plan (Plano de Cor), where one exists. We did not find that plan on the Portal do Munícipe.
National law. Article 6(1)(a) of the RJUE, as worded by Decree-Law 108/2026, exempts conservation works (restoration, repair or cleaning) from licence and prior notice. Article 80-A requires telling the council up to five days before work starts, including exempt works, but excuses conservation works carried out only inside. For listed buildings or buildings in a protection zone the rule is different (articles 4 and 6(k)). We could not confirm whether the special protection zone of the historic centre is in force, nor what the council requires for colours in that zone.
Scaffolding. According to the Portal do Munícipe, public space may only be occupied if the work is licensed or, if it is exempt, after submitting the notice of start of works. The page on occupation for works gives 20 working days minimum notice and 20 working days average response. The page on the notice of start gives 5 working days for that notice and 30 working days notice for the occupation (hoarding, site compound, platform or scaffolding). We cannot tell which one is right: ask the council before booking the painter. The Regulatory Code (article D-1/33-C) requires approved, painted metal scaffolding with outer netting or sheeting, and a 2.20 m walkway for tunnel scaffolding.
Areas near Porto
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Scaffolding in Porto: 20 or 30 working days?
On 3 November 2026 we read two pages of the Porto council’s Portal do Munícipe that contradict each other.
- Occupation of public space for works (updated 13 October 2026): minimum notice of 20 working days and an average response of 20 working days, for complete requests.
- Notice of start of works (updated 30 October 2026): the notice is filed up to 5 working days before the works, and the occupation request (hoarding, site compound, mobile platform or scaffolding) with 30 working days notice.
The second page also says the notice of start must be submitted before the occupation request. For a painter who needs scaffolding on a facade, the prudent choice is to plan for the longer deadline (30 working days) and to confirm with the council through the Linha Porto line that the Portal lists. Once the occupation is approved, an extension is requested 15 days ahead when the permit requires it (extension page of the same Portal; we did not read it to the end). For painting only the interior, there is no scaffolding and no occupation.
General notes
Under article B-1/31 of the Regulatory Code (November 2025), changing facade colour is exempt from prior control, but forbidden if it does not fit the building or harms historic groups. For a PDM Building of Heritage Value it needs a licence or prior notice. Check with the council.
The Portal do Munícipe gives two deadlines: 20 working days on the page about occupation for works and 30 working days on the page about the notice of start. We do not know which applies, so plan for 30 and ask the council.
At the Porto / Pedras Rubras station (IPMA, 1991-2020) rainfall is 1,146.9 mm a year, on 105.4 days with 1 mm or more. November is the wettest month (165.9 mm) and July the driest (16.6 mm). Frost is rare, 1.4 days a year.
Not lightly. Porto's Regulatory Code exempts changing exterior cladding 'without prejudice to the law protecting azulejo heritage'. We did not read the text of that law, so talk to the council before removing or covering tiles.
Under article 80-A of the RJUE, as worded by Decree-Law 108/2026, conservation works only inside buildings or units are excused from notifying the start of works, and conservation is exempt from licence. In a condominium, check the rules.
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