Whether a solar system only has to be notified or formally permitted and how long the procedure takes is regulated differently by each canton – based on the same federal legal foundation. Since 1 January 2026, the simplified notification procedure also applies to facade systems, no longer just to roofs. This table directly compares deadlines and responsibilities for six cantons side by side. (As of: September 2026)
Key points in brief
- The federal legal basis is Art. 18a of the Spatial Planning Act (RPG) – since 1.1.2026 expressly also for facade systems.
- The specific implementation (deadline, form, responsibility) is determined by each canton itself.
- The observed deadlines range from 20 to 30 days, with cantonal different exceptions for industrial/business zones.
- For objects with cantonal or national heritage protection, an ordinary building permit is always necessary.
What changed in federal law in 2026?
Until the end of 2025, Art. 18a RPG only recognised the simplified notification procedure for systems on roofs. Since 1 January 2026, it expressly also applies to systems on facades. The associated Spatial Planning Ordinance (RPV) concretises this in Art. 32a and Art. 32abis. An important exception remains: For objects under cantonal or national heritage protection, an ordinary building permit is always necessary according to Art. 32b.
How do the cantons differ in practice?
| Canton | Responsibility / Procedure | Deadline | Distinctive feature |
|---|---|---|---|
| Aargau | Municipal council, energievollzug.ch/ag (§ 49a BauV) | 30 days for objections | Industrial/work/business zones notification-free above standard size; ISOS-A objects need ordinary building permit procedure |
| Zug | Building notification, municipal building department (§ 44a PBG) | 20 days from complete documents | Leaflet (May 2024) outdated for facades – federal regulation 1.1.2026 authoritative |
| Schwyz | «Building notification for minor project», ebau-sz.ch (§ 75a PBG) | min. 20 days before start of construction; permitted without objection | Industrial/business/public zones: Notification also for unadapted facades; from 11 m fire protection concept |
| Thurgau | Political municipality (§§ 50a–50b PBV) | <35 m²: no notification/permit; ≥35 m²: 20 days | Work zones: only area/capacity count |
| Schaffhausen | Municipality, notification form in duplicate, free of charge (Art. 54 BauG) | 30 days | additional notification to the valuation office; ISOS special list |
| Zurich (incl. Winterthur) | cantonal platform «Report solar system» (§ 2a BVV) | 30 days | Facades up to 11 m: notification sufficient; above that building application (except single-family home) |
As of: September 2026. Source per row: cantonal leaflet/ordinance plus, where available, the cantonal notification platform. The currently published cantonal provisions are always authoritative.
For projects that started shortly after the turn of the year 2026, the new facade regulation had not yet been updated everywhere in the municipal leaflets – we have repeatedly experienced that an older leaflet falsely showed a facade system as requiring a permit, although the notification procedure applies under federal law since 1.1.2026.
Frequently asked questions
Does the simplified notification procedure also apply to facade systems since 2026?
Yes, under federal law since 1 January 2026 (Art. 18a RPG in conjunction with Art. 32abis RPV). Individual municipal leaflets were not yet consistently updated at the time of creating this overview.
In which canton is the procedure fastest?
Thurgau is the fastest for small systems (under 35 m²). For notification deadlines, Zug and Schwyz are ahead of Aargau, Schaffhausen and Zurich with around 20 days compared to 30 days.
Do I always need an ordinary permit for a heritage-protected building?
Yes, for cantonal or national heritage protection, an ordinary building permit requirement applies in all cantons compared here according to Art. 32b RPV.
Will this table be expanded to include other cantons?
Yes, each newly added canton is checked against its own official source.
Unsure whether notification or permit is necessary?
We clarify the procedural question for your canton and your municipality – as part of the project planning.
Sources: Fedlex (RPG Art. 18a, RPV Art. 32a/32abis/32b), cantonal leaflets and notification platforms.
Last updated: 18 September 2026 · Contact for questions on methodology: ecoEn editorial team
