# Painting and damp in Coimbra: Mondego fog, the Alta hill and 45% of buildings needing repairs

> Painting and damp in Coimbra, sourced: 31.6 foggy days a year (IPMA), 45% of buildings needing repair (INE), Alta heritage rules and the council facade scheme.

- Page: https://paredecerta.pt/en/painting-damp-coimbra
- Language: English
- Updated: 2026-11-03

## The walls of Coimbra

Coimbra has 40,701 buildings in the 2021 Census (whole buildings, not flats). 24.2% date from before 1961 and 29.1% from 1961 to 1980: together 53.3% are over 40 years old, against 50.2% nationally. The 1961-1980 group is the largest, with 11,841 buildings.

Repair need is the opinion of the census respondent, not a technical survey. The gap is still clear: 28.9% of buildings need light repairs (nationally 21.8%), 11.5% medium (9.4%) and 5.0% deep (4.6%). Only 54.6% need no work, against 64.2% nationally.

The city climbs from the River Mondego to the Alta hill, home of the University, and the historic centre has narrow streets and many old stone and render walls. This is a general description of the terrain, with no source of its own. For anyone repainting, what matters is the age of the building and whether the cause of a stain was fixed before the paint: on the Alta stonework the council has colour and finish rules, so check them before buying paint.

## Buildings (INE Census 2021)

- 40701 buildings counted in Coimbra
- 24.2% built before 1961; 82.4% built up to 2000
- 5.0% with deep repair needs (whole building)

- Antes de 1919: 1530 (3.8%)
- 1919-1945: 2901 (7.1%)
- 1946-1960: 5437 (13.4%)
- 1961-1980: 11841 (29.1%)
- 1981-1990: 6409 (15.7%)
- 1991-2000: 5428 (13.3%)
- 2001-2005: 3554 (8.7%)
- 2006-2010: 2537 (6.2%)
- 2011-2015: 484 (1.2%)
- 2016-2021: 580 (1.4%)

Source: INE, Census 2021, indicator 0011482, updated 2022-11-12. CC BY.

## Rain, damp and cold

At the IPMA station Coimbra / Bencanta (26.6 m above sea level, near the Mondego), the 1991-2020 normal gives 866.0 mm of rain a year, peaking in November (121.5 mm), October (114.5 mm) and January (113.5 mm), with only 8.9 mm in July. There are 94.0 days a year with 1 mm or more and 29.6 with 10 mm or more. The mean temperature is 16.2 °C and there are 6.0 frost days a year (minimum below 0 °C).

That 1991-2020 file has no humidity or fog table. The only figures we found are from the earlier 1971-2000 normal for the same station: mean relative humidity of 81% at 9 a.m. UTC (86% in January, 85% in November and December, 76% in May and June) and 31.6 days of fog a year, most in September (5.0 days) and October (3.4). That period also had 18.7 frost days, three times today's figure. The data is 30 years older: treat it as an order of magnitude.

What this means for walls: from October to January it rains a lot and the morning air sits near 85% humidity, which slows the drying of stone walls and favours mould on cold bedroom walls with little ventilation. Interior paint dries badly in those months; leave the work for spring or summer, when rain drops below 30 mm a month in June, July and August.

## Houses and walls

- The Alta and the Baixa have old stone-and-render buildings, built before 1961 in 24.2% of the municipality's buildings. Thick stone walls hold moisture and salt: scrape and let them dry before painting, and use a compatible render, preferably lime-based (the University-zone regulation asks for it). In general it is not a matter of paint alone.
- Coimbra's largest group, 11,841 buildings (29.1%), dates from 1961 to 1980: reinforced concrete with hollow-brick walls and little or no insulation. Thermal bridges at corners and beams by the facade cause condensation stains and mould in winter. This is a general building rule for that period, not a census figure.
- In the municipality's parishes outside the centre there are houses and rural homes; across the municipality 5.0% of buildings need deep repair. Ground floors with no air gap or drainage, next to land that takes water from the hill and the valley, tend to show rising damp, which needs the cause treated before any paint. This is general guidance, with no local source.
- Buildings from 1991 onwards number 12,583 of 40,701 (30.9%) and were built with more insulation. The commonest problem here is condensation from poor ventilation in tightly sealed homes: a matter of use and air, not paint.

## Rules and permits

**Exempt works.** Painting a facade without changing anything else is, as a rule, conservation work exempt from a licence and prior notice under the RJUE (Decree-Law 555/99, article 6(1)(a)). Decree-Law 108/2026 amended the RJUE on 1 October 2026 and we could not reopen the consolidated text for this page: confirm the article with the council. Coimbra's building and fees regulation (RMUE, Regulamento 381/2017) defines "facade structure" in article 4 as the sizing, composition and materials of the facade planes, openings, eaves and parapets: changing those is no longer just painting.

**Scaffolding.** The RMUE says, in article 66, that occupying public space for works exempt from prior control needs an administrative licence, requested up to 15 days before the start (para. 1). Starting depends on paying the fee and holding accident and civil liability insurance (para. 5), and the period cannot exceed the works (para. 6). Article 75 prefers aerial scaffolding, covered vertically with fine mesh or sheeting, and article 76 provides for pedestrian corridors. Loading and unloading of up to 24 hours pays no fee (article 73). This is the 2017 text: we did not confirm whether it has been amended since.

**Alta and Sofia.** The municipality approved a building and rehabilitation regulation for the area of the University's World Heritage bid and its protection zone. The only text we read is the draft published on 4 November 2011: it asks for traditional colours backed by a technical-historical study (article 6(4)(c)), bans textured, sanded, sponged or glossy paints on renders (d)) and favours lime-based renders (i)). We did not read the final version (Aviso 2129/2012) or later amendments: before painting in the Alta, Rua da Sofia or the historic centre, ask the council.

https://files.diariodarepublica.pt/2s/2017/07/140000000/1514615189.pdf

## Coimbra com Mais Encanto: paint and fee waivers for facades

The council runs a scheme that supplies paint, lime, primer and fixative and waives urban fees, public-road occupation fees and advertising fees for facade painting, up to 1,000 m² of painting. Owners, tenants or condominiums of legally built buildings in the municipality, at least 30 years old (or listed), can apply. Badly degraded facades must be repaired first, and colours and external finish need prior approval. Applications go through the council's online services or the Mercado Municipal D. Pedro V desk or the Loja do Cidadão.

According to the council's February 2025 news item, the scheme has run since 2002 and has supported 262 facades. In 2024 there were 15 applications and 5 buildings painted, with 180 litres of paint and 60 of primer (EUR 3,354.95 with VAT). We could not open the scheme's regulation (Edital 96): the council site refuses automated reading. We do not know whether the scheme is still open in 2026: ask the council.

## Sources

- [IPMA, climate normal 1991-2020, Coimbra / Bencanta](https://www.ipma.pt/bin/file.data/climate-normal/cn_91-20_COIMBRA_BENCANTA.pdf)
- [IPMA, climate normal 1971-2000, Coimbra / Bencanta (humidity and fog)](https://www.ipma.pt/bin/file.data/climate-normal/cn_71-00_COIMBRA_BENCANTA.pdf)
- [Regulamento n.º 381/2017 (Coimbra RMUE), Diário da República](https://diariodarepublica.pt/dr/detalhe/regulamento/381-2017-107720445)
- [Coimbra RMUE, text read: DR series 2, no. 140, 21 July 2017](https://files.diariodarepublica.pt/2s/2017/07/140000000/1514615189.pdf)
- [Draft regulation for the University World Heritage bid area, DR no. 212, 4 November 2011](https://files.diariodarepublica.pt/2s/2011/11/212000000/4392243930.pdf)
- [Município de Coimbra, news item "Coimbra com Mais Encanto" (February 2025)](https://www.coimbra.pt/2025/02/coimbra-com-mais-encanto-ja-apoiou-pintura-de-fachadas-de-262-edificios/)
- [INE, 2021 Census (0011482)](https://www.ine.pt/ine/json_indicador/pindica.jsp?op=2&varcd=0011482&lang=PT)
- [Photo: Gabriel de Andrade Fernandes, Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Coimbra_(31401775338).jpg)

## FAQ

### Do I need a licence to paint a facade in Coimbra?

As a rule, repainting a facade without changing anything else is conservation work, exempt from a licence (RJUE, article 6). The RJUE was amended in October 2026 and we did not reopen the text: confirm with the council. The Alta, Sofia and the historic centre have colour and render rules; under the council scheme, colours need prior approval.

### Can I put scaffolding on the street without asking the council?

No. Under Coimbra's RMUE (article 66(1)), occupying public space for works exempt from prior control needs an administrative licence, requested up to 15 days ahead. Only loading and unloading of up to 24 hours pays no fee (article 73). This is the 2017 text: check whether it was amended.

### Are fog and humidity in Coimbra a problem for interior painting?

IPMA recorded 31.6 foggy days a year and 81% mean humidity at 9 a.m. UTC at Coimbra / Bencanta (1971-2000). It rains 866 mm a year (1991-2020), over 110 mm in October, November and January. Paint in summer and fix the cause of the damp first.

### Which colours can I use on the Alta in Coimbra?

The 2011 draft regulation for the University zone asks for traditional colours backed by a technical-historical study and bans textured, sanded, sponged or glossy paints on renders. We did not read the final version in force, so ask the council for the rules of your street before buying paint.

### Does Coimbra council give paint for facades?

The Coimbra com Mais Encanto scheme supplies paint, lime and primer, up to 1,000 m², for buildings 30 years or older and waives fees, according to the council's February 2025 news item. We did not confirm that it is open in 2026 or its current rules. See the council's online services.

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Source: https://paredecerta.pt/en/painting-damp-coimbra. Independent information, not legal or tax advice.