This is an easy-to-read page.
Sometimes you do not need a building permit.
A notification to your municipal building committee is enough.
You can build a patio, shelter, shed, extension, outhouse, wall and fencing without a building permit.
You can also make changes to the façade and build two dormer windows without a building permit.
You may not build closer to the site boundary than 4.5 metres if the neighbours have not approved this.
Their approval should be in writing.
If the neighbours disapprove, the building committee may decide the matter through you applying for a building permit.
If your property is in the countryside, you are also allowed to make minor extensions.
This may be for new buildings, for example, a garage, guest houses and greenhouses as well as wall and fencing without a building permit or notification.
If you are unsure you should always ask your municipal building committee.
Other rules apply within certain areas and you cannot build anything there without a building permit.
You can read about
New building, rebuilding or extension
Applying for a building permit
Permit-free building – "Attefallshus"
Boverket's rules for how you can build
CE marking of building products