Background
#Flat-roof PV in Lucerne is no longer just an installation topic under the current municipal and cantonal requirements.
In the City of Lucerne, at least 30% of the roof area on flat roofs of existing buildings and new builds must be used for solar energy; at the same time, the city requires flat roofs to be greened. Since the amendment of the Energy Act and Energy Ordinance on 1 March 2025, Canton Lucerne also has its own rules on roof-area use. For owners, property managers and commercial buildings, this means: before requesting a quote, roof build-up, usable area, greening, mounting, glare risk, notification or permit route and incentives must be checked together.
Only then is it clear whether the system can be handled as a standard project or whether design, protection status or renovation require additional clarification.
For your roof
What does a system on your roof cost?
With your address we calculate price range, incentives and payback for your roof from federal data. We email the report straight away.
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Rather talk directly? +41 78 615 90 58
What roof and planning dictate
#The stricter requirement decides. The City of Lucerne expressly states that for new builds and roof renovations with substantial changes, both municipal building and zoning rules and cantonal energy law must be observed. For flat roofs, this means the question is not only which minimum area PV can technically occupy, but which municipal or cantonal obligation is stricter for the specific property.
Flat roof and greening belong together in Lucerne. The City of Lucerne requires not only solar use on flat roofs, but also greening. This makes the mounting system relevant: height, row spacing, maintenance access, vegetation build-up, wind suction and drainage must be planned so that PV yield and green-roof function do not work against each other.
The procedure question does not depend only on area. Solar installations from 20 m² in Lucerne are subject to notification and are submitted online via the cantonal energy notification. A building permit may still be necessary, for example when combined with other structural changes, in townscape protection areas, for inventoried buildings or if design criteria are not met.
Incentives are time-critical. The City of Lucerne supports photovoltaic installations in addition to federal support, but clearly states that the contribution application must be submitted before construction begins and that retroactive support is excluded. Anyone who installs first and sorts incentive documents afterwards may lose city contributions.
Glare and design can turn a standard project into a special case. The City of Lucerne mentions glare risk, including on flat roofs on slopes, and provides supplements for low-glare modules when glare impact is documented. For highly visible roofs, performance alone is therefore not enough; reflection and product choice should be checked early.
The process in five steps
#Tick off for your project
Separate location and legal framework
first clarify whether the building is in the City of Lucerne or only in Canton Lucerne. Then check whether it is a new build, substantial roof renovation or pure PV retrofit. This classification determines whether municipal BZR rules, cantonal KEnG/KEnV rules or both levels must be considered in planning.
Capture the flat roof technically
document roof area, parapet, penetrations, structural capacity, waterproofing, drainage, existing greening, maintenance routes and shading. For Lucerne flat roofs, this survey is especially important because PV layout and green roof must work together and cannot be solved only after module planning.
Determine notification or permit route
prepare the cantonal energy notification for installations from 20 m². In parallel, check whether renovation, heritage or townscape protection, inventoried building status, design or unmet criteria require a building application. In uncertain cases, the City of Lucerne recommends early clarification with the responsible advisory and building-permit offices.
Secure incentives before construction begins
prepare the city incentive application in the portal before work starts. In addition, classify the Pronovo one-time payment as federal support separately. Incentive application, technical data, attachments and planned construction start must align because retroactive city support is excluded.
Coordinate installation and grid process
only once roof concept, green-roof compatibility, procedure and incentives are classified should installation window, material ordering and grid-connection coordination be fixed. This keeps clear which approvals are needed before construction, before installation and before commissioning.
Checked for your roof, not just read up on
What does a system on your roof cost?
With your address we calculate price range, incentives and payback for your roof from federal data. We email the report straight away.
Free and non-binding · no unsolicited calls
Rather talk directly? +41 78 615 90 58
Frequently asked questions
#Sources
#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.