What can you build on your sommerhus plot in 2025?
Denmark updated its building code in July 2025. Here is what the current rules mean if you want to add something to your plot.
Updated March 2026
Denmark’s new building code BR25 replaced the former BR18 on 1 July 2025. For most sommerhus owners, the fundamentals remain the same. But a few updates are worth knowing.
Stricter CO₂ requirements now apply to sommerhuse over 150 m² and extensions over 250 m². For smaller projects, the impact is minimal. A new clarification makes explicit that secondary buildings cannot be placed within 5 metres of a road boundary. And noise from technical installations like heat pumps must now be managed for indoor comfort, replacing the old outdoor noise rule.
1. The 15% rule
Total built floor area on your plot may not exceed 15% of the plot size. On a 1,000 m² plot, that is 150 m² maximum, including all existing buildings. Some local plans set it as low as 10%. Always check your lokalplan first.
2. Secondary buildings under 50 m²
Sheds, carports, covered terraces and greenhouses can be built without a permit if the total combined area of all secondary buildings stays under 50 m². They must sit at least 2.5 metres from neighbours, 5 metres from roads, and no higher than 2.5 metres near boundaries. No windows or doors on the side facing the boundary. Maximum 12 metres of facade length toward boundaries across all secondary buildings.
3. What always requires a permit
Any construction that expands living area requires a building permit, regardless of size. A new annex, an extension, converting a shed into habitable space. Apply through Byg & Miljø. Do not start before the permit is issued.
4. Height and placement
Maximum height: 5 metres. Maximum wall height: 3 metres. Minimum distance to neighbours: 5 metres for habitable buildings, 2.5 metres for secondary buildings. One storey only. A hems (sleeping loft) does not count as a second storey.
5. Before you begin
Check your bebyggelsesprocent. Read the lokalplan. Measure distances to boundaries. Call your municipality’s byggesagsafdeling. A short conversation early on saves months later.
The rules protect what makes sommerhus areas worth living in. Working within them is the starting point for building something lasting.
Need help with your permit?
Our certified architect handles building permit applications across Denmark. Book a consultation and we take it from there.
*General guidance only. Building rules vary by municipality and plot. Always verify before beginning any project.
