What does upvc dormer (prefab) cost in 2026?

A prefab uPVC dormer costs on average € 6,500 to € 11,000, installed. A bespoke wooden dormer costs € 10,000 to € 20,000 or more. Width is the biggest price factor; window frames, glazing, crane access and a possible permit also count. Renovating an existing dormer costs € 1,500 to € 6,000.

On the rear side a dormer is often permit-free, as long as the design stays within the national rules — including sufficient distance from the roof edges and the ridge. On the front side, or on a roof surface facing public space, a building permit is almost always required, as it is for listed buildings and protected townscapes. Run the permit check on the Omgevingsloket or ask your municipality; a good builder often handles the application for you.

The installation itself of a prefab dormer is usually done in one day: in the morning the builder opens the roof, the crane lifts the dormer into place and the home is wind- and watertight again the same day. The lead time sits in the preparation: measuring, production and any permit. A bespoke wooden dormer takes several days of work on the roof.

uPVC is cheaper and low-maintenance: painting is never needed. Wood costs more but fits nearly any size and roof shape, and for listed buildings or protected townscapes it is often the only finish the aesthetics committee accepts. Exterior woodwork does follow the usual painting cycle of 5 to 7 years. Many builders combine: a wooden structure with low-maintenance cladding.

Sometimes. A roof window (€ 800 – € 2,500 including installation) brings daylight and fresh air into the attic and is usually installed within a day — but it adds no standing height or floor space. If you want to turn the attic into a proper room, the dormer remains the answer. Many residents combine the two: a dormer on the rear and a roof window on the front, where a dormer almost always needs a permit and a roof window often does not.

That depends on the width of the roof surface and the structure of the roof. Allow for clearance to the roof edges — certainly if you want to stay within the permit-free rules. Wider is relatively cheaper: the price per metre drops slightly as the dormer gets bigger. The builder measures up and advises what is structurally possible.

Not on every roof. Sufficient pitch and height are needed to fit a dormer with standing height; with a low pitch or a flat roof, a roof extension is the alternative — a different kind of project. When measuring up, the builder assesses whether the roof structure can carry the weight and what is structurally possible.

Yes. Submitting a request costs nothing and commits you to nothing. Up to 3 dormer builders respond and you decide who to talk to — or no one, which is fine too. Prices and payment are arranged directly with the company.

Dormer builders in your region respond as soon as possible with a price indication or an appointment to measure up. In spring, when diaries fill, it can take slightly longer — whoever requests well in advance plans easiest.

Yes. We verify Chamber of Commerce registration and business liability insurance before a company receives requests. Companies with recurring complaints are removed from the platform.

Your details are shared only with the (up to 3) dormer builders matched to your request. We never resell your data and automatically delete requests after the legal retention period. See our privacy policy.

Yes, often. In a renovation (€ 1,500 – € 6,000) the structure stays and cladding, side panels, fascia boards, frames or glazing are renewed — almost always cheaper than full replacement. A good builder first assesses whether the structure is still sound and gives honest advice on when replacement would be wiser after all.

Warranty arrangements are made directly with the builder. Many dormer builders give a multi-year warranty on the structure and the watertight connection to the roof; manufacturer warranties on frames and glazing differ per producer. Always have the terms laid down in writing in the quote and keep the invoice.