Solar installation (special case) in the canton of Solothurn: building permit needed?
Depends on size and location
Short answer: adapted roof/façade installations: notification procedure (Solar Installations Guide, canton of Solothurn 2026). Protected zones, open land, solar carport: building permit.
Legal basis: Art. 18a RPG, Solar Systems Guide SO. Planning and Building Act (PBG) and Cantonal Building Ordinance (KBV). As of October 2026. Applies within the building zone and outside historic core zones and protected areas. Municipalities may be stricter.
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What specifically applies in the canton of Solothurn
Since 2026, normal roof and façade systems only need a notification. A building permit is still required for systems in core zones and protected areas, on protected buildings, free-standing systems, solar fences and solar carports. These are exactly the cases solar installers often leave aside; we take them on.
Permit-free in the canton of Solothurn: only very minor projects expressly listed in § 3ter KBV are permit-free. Garden sheds, roofed pergolas, carports and pools generally need a building application.
Procedure: Solothurn is considered a restrictive canton: permit-free projects are exhaustively listed in § 3ter KBV (revised 2024). In case of doubt, the building authority decides whether a project is considered minor.
Submission: digitally via eBau Solothurn in activated municipalities, otherwise to the municipality using the cantonal form.
Note the official municipal instructions in the canton of Solothurn and our document checklist.
Our fixed price for a solar installation in the canton of Solothurn
- Preliminary check CHF 149, written assessment with the procedure, documents and fee range of your municipality. Credited towards the application.
- Building application CHF 1'290, complete dossier, submission, queries and deadlines until the decision. Excl. municipal fees.
- Retrospective building application CHF 990, if a solar installation is already in place and the municipality requires an application.
Frequently asked questions
Does a solar installation (special case) need a permit in the canton of Solothurn?
It depends on size and location. Adapted roof or façade systems: notification procedure (Solothurn solar installation guidelines 2026). Protected zones, open ground, solar carport: building permit. Legal basis: Art. 18a RPG, Solothurn solar installation guidelines.
Which procedure applies in the canton of Solothurn?
Solothurn is considered a restrictive canton: permit-free projects are listed exhaustively in § 3ter KBV (revised in 2024). If in doubt, the building authority decides whether a project counts as minor.
Who may submit the application in the canton of Solothurn?
No formal professional qualification is required. You give us a power of attorney; the client and the landowner sign the application.
How much does the building application for a solar installation in the canton of Solothurn cost?
Our fixed price is CHF 1'290 for the dossier, including submission and follow-up questions. Authority fees and agreed additional services are extra; the official tariff depends on the location.
Municipalities in the canton of Solothurn
Solar system (special case) in other cantons
Solar installation (special case) in the canton of Solothurn: we submit the application.
Assessment in 2 working days, dossier in 5. Enquire without obligation.