Building permits and notifications: what applies before you build?

You as the developer are responsible

Under the Planning and Building Act (plan- och bygglagen), the developer (byggherre) – that is, the person who carries out or has building work carried out on their own behalf – is responsible for ensuring that the work complies with the rules. When you hire a company to build on your property, you are usually the developer. This means it is your responsibility to apply for a building permit or submit a notification when required, even though you can ask the company to help with the documents.

If you build without the necessary permit or start notice (startbesked), the municipality can charge a building sanction fee and in some cases require the work to be removed.

When is a building permit needed?

A building permit is generally required for new buildings, and for many extensions and alterations of buildings, for example when the use of a building changes or when its external appearance is significantly affected. What is required depends on whether the property lies inside or outside a detailed development plan (detaljplan), what the plan says and whether the building is of cultural and historical value. The municipality may also have its own provisions in the detailed plan.

When is a notification needed?

Some measures do not require a building permit but must be notified to the municipality, and you may not start until you have received a start notice. This often applies to measures affecting load-bearing structures, ventilation, water and drainage or fire safety, as well as the installation of a fireplace or stove. Certain buildings and extensions that are exempt from building permits also require notification.

Attefall and the new rules from December 2025

The rules on what you may build without a building permit changed on 1 December 2025. The previous concepts of attefallshus and friggebod have been replaced by new concepts such as komplementbyggnad (ancillary building) and komplementbostadshus (ancillary dwelling), and the rules on size, placement and notification have changed. Exactly what applies depends, among other things, on whether the property lies inside or outside a detailed plan and what has already been built on the plot.

Since the rules are new and the details matter, you should always check with your municipality's building committee before you build, and read Boverket's information on building work exempt from permits.

Inspection manager and inspection plan

Many measures that require a permit or notification need an inspection plan (kontrollplan), and larger projects also need a certified inspection manager (kontrollansvarig). The municipality will tell you what is required in your case, often at a technical consultation. For a new build or larger extension of a small house, completion insurance (färdigställandeskydd) may also be required.

What applies to indoor renovation?

Ordinary indoor renovation, such as painting, laying a new floor or replacing a kitchen, normally requires neither a building permit nor a notification. But if you remove or alter load-bearing walls, reroute ventilation or change water and drainage in a way that affects the building, a notification may be required. In apartment blocks and tenant-owned flats you will also usually need permission from the housing association or landlord for certain changes.

How to proceed

• Describe what you want to do and contact your municipality's building committee to find out whether a permit or notification is required.
• Prepare the drawings and documents the municipality asks for.
• Wait for the building permit and start notice before work begins.
• Follow the inspection plan and keep documentation during the work.
• Apply for a final notice (slutbesked) where required, before the building is taken into use.

Tell the companies you request quotes from if the project requires a permit or notification, so that they can plan the schedule accordingly. Feel free to ask whether they have experience of preparing documents, but remember that the responsibility lies with you.

Frequently asked questions