28 June 2026

Dormers and permits: when is one permit-free?

Rear side often permit-free, front side almost never — the rules of thumb, the exceptions and what it means for your planning.

The rule of thumb: a dormer on the rear of your home is often permit-free, as long as the design stays within the national rules — among other things keeping sufficient distance from the roof edges and the ridge, and staying within the roof surface. On the front, or on a roof surface facing public space, a building permit is almost always required. For listed buildings and protected town- or villagescapes it always applies, including at the rear.

The exact dimensions and conditions are precise and differ per situation. So always run the permit check on the Omgevingsloket (the Dutch online permit desk) or ask your municipality — and record in the quote who handles any application. Good dormer builders file these applications routinely for their customers and will design within the permit-free rules if you prefer.

For your planning, needing a permit mainly means: start earlier. The municipality's processing time comes on top of measuring and the production time of a prefab uPVC dormer or the carpentry of a bespoke wooden dormer. The installation itself is then usually done in a single day.

Cost-wise a permit changes the picture only modestly: you pay a municipal fee (the amount differs per municipality) and the builder sometimes draws up extra documents. The guide prices for the dormer itself are in the price index — with a permit involved, ask for a quote that includes the permit process, so you compare complete offers.