Do you need a permit in Leiden? Extensions, dormers and renovations

Leiden has one of the largest historic town centres in the Netherlands, with narrow houses, small yards and many listed buildings. Outside that core the national exemptions apply as normal. In the historic centre and the southern ring around it, stricter rules apply. This page explains when an extension, dormer, roof window or internal renovation can be permit free, and how to check your own address.

First: technical and planning rules

Under the Environment and Planning Act (Omgevingswet) every building plan has a technical part, checked against the Buildings Decree (Besluit bouwwerken leefomgeving, or Bbl), and a planning part, checked against the municipality's environment plan (omgevingsplan). Permit free does not mean rule free: the Bbl and the neighbour rules in the Civil Code always apply. This page explains how it works in Leiden. It is not permit advice: only the online permit check or the municipality (gemeente) can confirm what applies to your address.

Extensions: the national rules

On the technical side, a side or rear extension is permit free if it stands on the ground, is no higher than 5 metres, has no habitable room on the second storey and no roof terrace or balcony (Bbl article 2.25).

On the planning side the dowry rules (bruidsschat) apply: national rules copied into every environment plan in 2024. The extension must be in the rear yard area, starting 1 metre behind the front facade, and more than 1 metre from public space (article 22.27). Within the article 22.36 limits below it can ignore the old zoning plan. Municipalities may change these rules.

Dormers and roof windows

A dormer (dakkapel) is always permit free technically (Bbl article 2.27(2)(a)); a full roof extension is not. On the planning side, a dormer on the rear slope, or a side slope not facing public space, is free under Bbl article 2.29(b), which overrides the environment plan. The conditions are listed below.

At the front, a dormer is only free where no design requirements (welstand) apply (dowry article 22.27(c)). A roof window is free on the rear slope or a flat roof if it sticks out no more than 0.6 metres and stays 0.5 metres from the edges (Bbl article 2.29(c)). On a listed building, and in a state protected area on a slope facing public space, you need a permit (Bbl article 2.30).

• Flat roof.
• No higher than 1.75 m.
• Bottom more than 0.5 m and less than 1 m above the eaves.
• Top more than 0.5 m below the ridge.
• Sides more than 0.5 m from the edge of the roof slope.

Renovating inside the house

Internal work is permit free as long as the load bearing structure and fire compartments stay the same (Bbl article 2.27) and the building volume does not grow (dowry article 22.27(i)). A new bathroom or kitchen usually falls under this. If you remove a load bearing wall, IPLO, the government's information point for the Act, says you need a permit for the technical building activity. In a national monument (rijksmonument) even internal work often needs a monument permit. Normal maintenance stays free.

What Leiden's environment plan adds

Leiden checks a plan that needs a permit against the environment plan, its local bylaw on the physical environment, the design guide (Welstandsnota) and the heritage bylaw. Plans that are permit free nationally do not go through that. Anything beyond them, such as an extension deeper than the dowry rules allow or a front dormer, falls under the Leiden rules for your plot. The city explains this on its Dutch page Omgevingsvergunning aanvragen.

If you are unsure whether a plan is feasible, you can submit a preliminary request (conceptverzoek), even for a plan that is still an idea. It is then discussed at an internal meeting covering every aspect, including design.

In the historic centre, yards are often small and border other yards or water. The room the dowry rules give in theory is soon used up there by the protected status and the area limits. For an extension in those streets we therefore start by assuming a permit route.

Design review, protected areas and listed buildings in Leiden

According to the city, Leiden's protected townscapes are the historic centre and the southern ring. In those areas, and for historic buildings, stricter design requirements (welstand: whether a building looks right in its setting) apply. In a state protected area Bbl article 2.30 and dowry article 22.28 also apply, so a dormer on a slope facing the street, for example, always needs a permit.

The Leiden design guide includes quick test criteria for common small plans, such as dormers, extensions and window frame changes. If your plan meets them, the city handles it quickly without advice from the Welstands- en Monumentencommissie Leiden (WML), the design and heritage committee. If not, the WML gives advice and explains what you could change. The Dutch page on design and heritage review describes this. Solar panels in the protected area have their own rules in chapter 7 of the guide, with a map.

Almost every change to a listed building, inside or out, needs an environment permit. In the permit check, add the search word monument as well as the building activity. For advice and grants, the city refers to Erfgoed Leiden en Omstreken.

Owners' associations and renting

A permit only means the government agrees. In a flat, the facade, roof and usually the load bearing walls belong to the owners' association (Vereniging van Eigenaren, or VvE). A dormer, extension or new opening then needs a VvE decision under the deed of division (splitsingsakte). The municipality does not check this.

If you rent, you need the landlord's consent for an extension, dormer, kitchen or bathroom. The landlord must reply within 8 weeks and may only refuse if the home becomes harder to let or loses value (Civil Code article 7:215).

How to check it yourself

Work through these steps in order for your own address. You will know before the first drawing whether to plan for a permit. The national portal is in Dutch and you need DigiD to apply.

If you get stuck, call the city on 14 071. The Leiden International Centre helps newcomers with practical questions. If you want to know what is possible structurally, contact us for a visit by Stas. For a full renovation we include the permit in the planning.

• See what the city offers in English on its English pages.
• Run the permit check. For a listed building, add the search word monument.
• Look up the rules for your plot in Rules on the map.
• Read the Dutch page on the design guide and see whether your plan fits the quick test.
• Check your building in the national monuments register and on the map of protected areas.

Frequently asked questions