Short answer
Do I need a building permit for my solar system in Canton Aargau?
A practical initial check for owners: identify the roof or facade rules and protected status, prepare the plans for EVEN, then establish the earliest possible installation date.
Important
Notification is not blanket clearance: check building protection, townscape rules, municipal design rules and other technical duties for the specific project. The municipality handles objections and determines the applicable building procedure.
At a glance
Key figures: PV permitting Canton Aargau
| Metric | Value |
|---|---|
| Pitched roof | Among other rules: max. 20 cm, compact and low reflectivity |
| Flat roof | Alternative: max. 1 m, invisible at 45° and low reflectivity |
| Facade | Notification for sufficiently adapted systems since January 2026 |
| Starting work after notification | After at least 30 days from municipal receipt without objection |
Decision points
What determines the right path.
Pitched roof: Art. 32a para. 1 RPV requires a projection no higher than 20 cm perpendicular to the roof, no extension beyond the roof surface when viewed from above, low-reflectivity modules and a compact layout. Technically necessary gaps or an offset layout due to available space are allowed. The 45-degree visibility test belongs to the alternative flat-roof rule.
Flat roof: under Art. 32a para. 1bis RPV, an alternative route applies if the system rises no more than 1 m above the top of the roof edge, cannot be seen from below at a 45-degree angle from that edge and has low reflectivity. Show both height and setback in the section drawing.
Facade: since January 2026, notification is enough if at least one design option in Art. 32abis para. 1 RPV is met, such as a compact rectangular area, uniform replacement of existing facade elements or a colour similar to the adjoining facade. The shared conditions in para. 2 also apply: do not cover decorative features or extend beyond the facade edges; mount parallel and no more than 20 cm from the facade; use uniform, low-reflectivity materials. Area-specific design rules may also apply.
Protected status takes priority: § 49a para. 2 BauV requires a building permit for systems on or attached to buildings under substance protection and in zones with heightened townscape or landscape requirements. These include village, old-town and core zones and certain hamlet zones. Art. 18a para. 3 RPG also requires a permit for cultural or natural monuments of cantonal or national importance; for ISOS townscapes, check the affected area and conservation objective.
In industrial, work and commercial zones, § 49a para. 1 BauV exempts roof systems from the permit requirement even when they project more than 20 cm above the roof surface; the cantonal procedure page also names flat roofs more than 1 m above the roof edge. Notification and any protected status still apply. Do not automatically extend this roof exception to facades.
The AG-Solar form is also required for systems needing a building permit and is submitted with the building application (§ 22c EnergieV). For notification-only projects, submit it through EVEN. The 30 days before work may start run from receipt by the municipality and only apply if it raises no objection (§ 61a BauG).
Sequence
How the project stays cleanly managed.
- 1
Check the location before detailed designreview the municipal zoning plan and building rules (BNO), cantonal and municipal protected buildings, and any ISOS area and conservation objective on the AGIS map. Ask the municipality if protected status is unclear.
- 2
Record system type and dimensionsfor pitched roofs check height, roof boundary and module layout; for flat roofs show height over the roof edge and sightline in a section; for facades document one Art. 32abis RPV design option and all additional conditions.
- 3
Prepare the AG-Solar documentsan elevation of the building showing the system, a section with dimensions, the module data sheet and an orientation plan under the VKF fire-safety guidance for solar systems. The canton’s 2026 solar guide lists these attachments for notification-only projects.
- 4
Submit AG-Solar through EVEN and record when the municipality receives it for scheduling. If a permit is required, include the same form with the building application; notification does not replace that application.
- 5
For a notification-only project, begin installation no earlier than 30 days after municipal receipt and only if there has been no objection. If the municipality objects or a permit is required, follow the additional procedure and await the permit decision.
Checklist
Questions to settle before the quote.
- Assess pitched and flat roofs separately under Art. 32a RPV
- Facade PV since 2026: Art. 32abis RPV and municipal rules
- Protected status, EVEN documents and 30 days without an objection
FAQ
More questions: PV permitting Canton Aargau
Sources
Official sources & references.
The responsible authorities are decisive. Always verify binding details – amounts, deadlines and conditions – for your specific property against the current status of the respective authority.
- 2026 solar guide: design, procedure and attachmentsCanton Aargau, Energy Division
- AG-Solar: register and notify solar systems through EVENCanton Aargau, Energy Division
- Building Act § 61a: 30-day notification periodCanton Aargau, Statute Collection
- Energy Ordinance § 22c: notification and platformCanton Aargau, Statute Collection
- 2026 legal change: facades and § 49a BauVCanton Aargau