A quote tells you what a job costs. An independent inspection tells you the condition of the roof. This guide says who can do one, what a drone and a thermal camera are worth, what the report should contain, when it pays to hire one and what the municipality does with a dangerous roof.
Updated on 4 November 2026. General information, not legal or technical advice. We do not name firms or give prices: we found no official fee table.
The essentials
- We found no law that reserves roof inspection to one profession. Choose a civil engineer, a technical engineer or an architect registered with their professional order.
- A drone only sees the surface. A thermal camera measures surface temperatures. Neither replaces a visit to the loft.
- The report should say what was not seen, and why.
- Do not climb onto the roof: see work at height.
- The municipality can order works on an unsafe building, at the request of any interested party (RJUE, article 89).
Who can do the inspection
Law n.º 31/2009, amended by Law n.º 40/2015, says that projects are produced by architects, engineers and technical engineers with valid registration in their orders (article 10). But it covers design, supervision and site management. An inspection report is not a design, and we found no rule that reserves it.
The Statute of the Order of Engineers puts «peritagem» (expert assessment) within the engineer’s field (article 7), but it reserves only the acts that the law declares exclusive; others may be done by people who are not registered (article 7-A). Ask for the member number and check it: the Order of Engineers has a member search.
The statute requires opinions to be objective and impartial, forbids taking on work beyond one’s competence and says to refuse work that creates ambiguous situations (article 143, n.os 4, 6 and 8).
Also ask about experience with your type of roof and about professional liability insurance, which the law requires of those who do design, supervision and site management (article 24). In our reading, the person who inspects should not be the person who sells the works.
What a drone and a thermal camera show
The APICER and CTCV guide (2018) provides for an exterior inspection from an adjoining building, a high vantage point or with a drone, and a separate one from the loft. In our reading: a drone shows the surface and flashings, not the timber or the linings; a thermal camera shows temperatures, not water; only the loft shows the structure.
Drone rules. Regulation (EU) 2019/947, which ANAC applies, requires the operator to register if the drone has a sensor able to capture personal data, such as a camera (article 14). In the open category you fly in line of sight and below 120 m. Subcategory A2 asks for 30 m from uninvolved people (5 m in slow mode); A3, 150 m from residential areas, which is rarely possible in a built-up area. Ask the pilot for the operator number, the certificate and the insurance (ANAC refers the limits to Portaria n.º 2/2021).
A person who gives explicit consent and receives the safety instructions counts as «involved»; neighbours and passers-by do not (ANAC FAQ, 2024). On privacy, we found no ANAC rule and no CNPD guidance for drones. The CNPD says fixed home cameras may not capture the neighbour or the public road; extending that to a drone is our reading.
Thermography. LNEC explains that the technique only works with heat flow; for the passive method it normally recommends more than 10 ºC between inside and outside. A NOVA FCT dissertation (2014) adds limits: emissivity, reflection and weather change the reading, and deep anomalies are hard to detect. It has been studied on façades and on flat roofs; for tiled pitched roofs we found no source. Treat it as a lead, to be confirmed on site.
What the report should contain
The official method for assessing buildings (LNEC, 2007, on the Portal da Habitação) works as a model. It splits the roof into six elements and grades anomalies as slight, medium, serious and very serious: main structure; secondary structure (purlins, rafters, battens); waterproofing; other coverings; glazed openings; drainage.
The method says to get onto the roof or into the loft. If that is impossible, the technician observes from outside, looks for signs of water ingress and states that the finding rests on signs only.
Ask in writing for:
- who inspected: order, member number, date;
- scope: what was seen, how (loft, exterior, drone, moisture meter) and what was not seen;
- photographs, dated and located;
- findings by element, separating cause from symptom;
- urgency: what is a danger, what to do now and what can wait;
- possible solutions, without naming a firm;
- signature and a statement of independence.
APICER warns that dirt leads to wrong diagnoses and that the report should say whether further tests are needed. For timber, see woodworm and termites.
When it pays
A contractor’s quote exists to sell a job; the report describes the roof. The interest is different: see how to choose a contractor and repair or replace.
- Before buying: avoids finding the work after the deed. Ask the seller for access before signing.
- After a storm: independent proof of damage; the insurer usually sends its own assessor (see insurance and the first 48 hours).
- Before a big quote: a basis for comparison.
- A disputed defect: the Civil Code lets either party ask for verification by experts (article 1218, n.º 3).
The 30-day period to report a defect runs from when you discover it (article 1220): do not wait for the report. See the works warranty.
The owner of a building that collapses, wholly or partly, through a maintenance defect answers for the damage unless they prove they were not at fault (article 492); a threatened neighbour can demand measures (article 1350). A dated report and completed works show diligence (our reading).
Checklist: what you can see from the ground
- Broken tiles, a crooked ridge, a leaning chimney (with binoculars).
- APICER’s warning signs: marked deformation, parasitic vegetation and degraded drainage.
- Indoors (signs from the LNEC method): stains on top-floor ceilings, loose plaster, extensive mould.
- In the loft, step only on joists and take photos. If it is fibre cement, do not touch it (asbestos).
- Ask two professionals for a quote with a fixed price and scope, in writing. See the pre-winter check.
The municipal inspection
The RJUE requires maintenance works at least every eight years and whatever is needed for safety (article 89, n.º 1). The municipality may, at the request of any interested party, order unsafe conditions to be corrected (n.º 2) or order demolition of what threatens to fall (n.º 3). Before that there is an inspection (article 90):
- three technicians appointed by the municipality, two with legal qualification to be a project author;
- the owner is notified by registered letter, at least seven days ahead;
- until the day before, the owner may name an expert and put questions, which the report must answer;
- the report describes the state of the property, with its conservation level (Decreto-Lei n.º 266-B/2012), and the works recommended;
- where collapse is imminent, the formalities are waived.
If the owner does not do the works, the municipality may take administrative possession of the property and carry them out (article 91). We found no service on the Portal da Habitação for requesting this inspection: go to your municipality.
See also: Before buying a house, see what to check on the roof.
What we could not confirm
- The current version of Law n.º 31/2009: the copy we read is from 2018; Law n.º 3/2026 made a third amendment that we did not read.
- Whether any law reserves roof inspection: we found none, but we did not read everything.
- The current drone regulation: ANAC’s copy is from 2020; we did not read Portaria n.º 2/2021 or the insurance amounts.
- Privacy and the owner’s permission to fly over land.
- Thermography on tiled roofs and its cost.
- How to request the inspection, deadlines and fees; the text of Decreto-Lei n.º 266-B/2012.
- Whether the order’s member search proves registration.
Sources (read on 4 November 2026)
- RJUE (Decreto-Lei n.º 555/99), consolidated version at PGDL, articles 88-A to 91, including DL n.º 108/2026.
- Law n.º 31/2009, consolidated version of 14-6-2018; OET, note on Law n.º 3/2026.
- Order of Engineers, Statute and member search.
- Regulation (EU) 2019/947, consolidated text of 6-6-2020; ANAC, FAQ, 6-6-2024.
- CNPD, video surveillance by neighbours.
- L. Matias (LNEC), Infrared thermography; A. C. Melrinho, Anomalies in flat-roof waterproofing, NOVA FCT, 2014.
- LNEC, Method for assessing the conservation state of buildings, 2007.
- APICER and CTCV, Guide to Ceramic Roof Tiles, 2018, section 7.3.
- Civil Code, 492, 1218 and 1220 and 1350.