01
Since 1 Mar 2025requirement for qualifying roof renovationsUrbanHome · Lucerne solar requirement 2026
Solar requirement for roof renovations in the Canton of Lucerne: rules and exceptions in 2026
Anyone replacing a roof covering or waterproofing layer in the Canton of Lucerne may have to use part of the roof’s electricity-generation potential or pay a substitute levy. The rule has applied since 1 March 2025 and remains in force in 2026, but it does not cover every minor repair and includes clear area, suitability and exemption rules.
Author: Nikita von Niederhäuser, UrbanHome real estate expert27 October 2026 · Reading time: approx. 15 minutes
02
≈ 25%of usable roof area as a simplified PV minimum03
CHF 1,000/kWsubstitute levy per missing kW04
> 25 m²only suitable roof sections count as usable areaKey point
Not every roof job triggers the requirement.
For existing buildings, the Lucerne rule is tied to a roof renovation that involves replacing the roof covering or waterproofing. Pure fastening, repair or maintenance work is not enough. The building’s energy use and the suitability of individual roof sections also matter. [2]
KEnG § 15 · KEnV §§ 13–15 · 2026
01
New roofing or waterproofing
For pitched roofs this usually means full replacement of the covering on a roof section; for flat roofs, replacement of the waterproofing layer.
02
Only energy-using buildings
The rule applies to existing buildings that are heated, ventilated, cooled or humidified. Buildings without such energy use are exempt under the cantonal enforcement guidance.
03
Electricity generation, not PV only
The law requires use of the electricity-generation potential. PV is the standard route, but equivalent generation within the same site and ownership can be credited.
Scope in 2026
When does the solar requirement apply to a roof renovation?
Four questions determine whether the obligation is triggered in practice.
01
Building
Is the building heated, ventilated, cooled or humidified?
Only then does § 15 KEnG apply in principle.
02
Work
Is the roof covering or waterproofing being replaced?
A simple repair or maintenance job does not generally trigger the requirement.
03
Roof area
Are there suitable roof sections?
Only sections over 25 m² that can accommodate at least six connected PV modules and are rated at least “good” for existing buildings count.
04
Exception
Is there an exemption or technical limitation?
Yield, heritage restrictions, geometry, shading and special building types can reduce or remove the requirement.
Calculation
How large must the solar installation be?
Lucerne distinguishes between usable and coverable roof area. Existing buildings undergoing roof renovation must meet half of the new-build requirement. [2]
EN-204-LU
25%Example: 120 m² of usable roof area
If 120 m² genuinely qualifies as usable roof area, 60 m² is defined as coverable. For a roof renovation, half of that requirement applies: roughly 30 m² of PV-equivalent area. At 200 W/m² this gives a simplified minimum of around 6 kW. The binding calculation uses EN-204-LU and the actual roof geometry.
01
Determine usable roof area
Count suitable roof sections over 25 m² that can accommodate six connected modules and are rated at least “good” on sonnendach.ch.
02
Coverable roof area = 50%
Fifty percent of usable roof area is defined as coverable roof area.
03
Roof renovation = half the new-build requirement
Existing buildings only have to meet half of the new-build rule. In simplified terms this equals about 25% of usable roof area.
04
Use 200 W/m²
The ordinance assumes 200 watts of installed PV capacity per square metre of PV area.
Exceptions & relief
When can the requirement disappear or be reduced?
The Lucerne rules are technically differentiated and do not treat every roof the same way. [2]
01
Small or unsuitable sections
Roof sections up to 25 m² do not count towards usable roof area. Sections with expected annual yield below 800 kWh per kWp are also exempt.
02
Geometry or shading
If the minimum coverage cannot be achieved because of demonstrable building-specific constraints, installing the maximum technically possible coverage is sufficient and no substitute levy is due for that shortfall.
03
Protected elements
The competent cantonal service may grant relief for external building elements subject to protection requirements. Protected buildings may also require a building permit.
04
Special structures
Air-supported halls, greenhouses, glazed-roof conservatories, foil tunnels and comparable structures are exempt.
Alternative
Substitute levy instead of the installation
If the required capacity is not installed, a statutory substitute levy may be due. It is CHF 1,000 per kW of missing capacity and is collected by the municipality. The levy is due when the required capacity is missed by more than 1 kW. [2]
CHF 1’000 / kW
Example: if 6 kW is required but only 4 kW is installed, the shortfall is 2 kW and the levy is generally CHF 2,000. If building-specific limitations are properly demonstrated, the maximum feasible roof coverage can instead satisfy the requirement.
Process
How owners should proceed in 2026
2026
6How owners should proceed in 2026
EN-204-LU · EVEN · Gemeinde
01
Define the roof works
Clarify whether roofing or waterproofing is actually being replaced or whether the project is only repair and maintenance.
02
Assess roof sections
Record suitable sections, size, module layout and solar suitability.
03
Calculate EN-204-LU
Determine the required on-site generation using Lucerne’s EN-204-LU guidance and form.
04
Document exceptions
Provide early planning evidence for shading, heritage constraints or other technical limitations.
05
Clarify the municipal procedure
Depending on the installation, a notification or building permit may apply. Energy evidence has been submitted digitally through EVEN since 2026.
06
Build or account for the levy
Install the required capacity or include the statutory substitute levy in the project planning.
Status: 27 October 2026
The rule is politically contested, but it remains in force
A motion is pending in the Lucerne Cantonal Council seeking to remove the on-site electricity-generation requirement for roof renovations from § 15 KEnG. The official parliamentary business page still lists Motion M 618 as pending. This does not change current projects: the rules in force since 1 March 2025 continue to apply until any legislative amendment enters into force. [6]
Checklist
Check before renovating the roof
01–05
Check before renovating the roof
Is the building heated, ventilated, cooled or humidified?
Will roofing or waterproofing be replaced?
Which roof sections are larger than 25 m²?
Can at least six connected PV modules be installed?
Are the sections rated at least “good” on sonnendach.ch?
06–10
Check before renovating the roof
Are there shading, dormers, lift overruns or heritage restrictions?
What minimum capacity results from EN-204-LU?
Will PV, solar thermal or another eligible solution be used?
Is a notification or building permit required?
What substitute levy would apply to any shortfall?
Sources
Official sources and legal status
Legal status checked on 27 October 2026. The decisive sources are the Lucerne Energy Act, Energy Ordinance and cantonal EN-204-LU enforcement guidance.
- Kanton Luzern: KEnG kompakt – Eigenstromerzeugung
- Kanton Luzern: Kantonale Energieverordnung (KEnV), §§ 13–15
- Kanton Luzern: Merkblatt Solaranlagen, Version 1.4 ab 01.01.2026
- Kanton Luzern: Energienachweise ab 01.01.2026
- Kanton Luzern: Vollzugshandbuch Energie, LU EN-204
- Kantonsrat Luzern: Motion M 618 zur Solarpflicht bei Dachsanierungen
UrbanHome: general information only; not individual legal or construction advice.
Living
Related guides
UrbanHome guides to summer heat protection, building improvements and budgeting for property costs.
01
Installing air conditioning in Switzerland
Permits, summer heat protection, energy requirements and practical alternatives to active cooling.
02
How much house can I afford in Switzerland?
Calculate affordability and allow for maintenance, repairs and energy-efficiency upgrades.
direct answer
Frequently asked questions about the Lucerne roof-renovation solar requirement
Direct answers on scope, area, exceptions and the substitute levy.
10FAQ
Yes. Since 1 March 2025, qualifying roof renovations on existing energy-using buildings must use the electricity-generation potential appropriately or generally pay a substitute levy.
No. A roof renovation mainly means new roofing or waterproofing. Pure fastening, repair and maintenance work does not generally trigger the obligation.
No. Existing buildings undergoing roof renovation meet half of the new-build requirement. In simplified terms, this is about 25% of usable roof area.
Usable area generally consists of roof sections over 25 m² that can accommodate at least six connected PV modules and are rated at least “good” on sonnendach.ch for existing buildings.
The ordinance assumes 200 watts per square metre of PV area. The binding proof is calculated with EN-204-LU.
Yes. Roof sections with expected annual yield below 800 kWh per kWp of installed capacity are exempt.
The competent authority can grant relief for protected external building elements. A building permit may also be required for protected properties.
CHF 1,000 per kW of unrealised capacity. It becomes due when the required capacity is missed by more than 1 kW.
Yes. On pitched roofs, 1 m² of solar thermal counts as 1 m² of PV area; on flat roofs, 1 m² of solar thermal counts as 3 m² of PV area.
Not at present. A motion seeking removal of the roof-renovation requirement is pending, but the existing rules remain legally effective until any amendment is adopted and enters into force.
UrbanHome · LivingMore guides →
Key takeaway
Plan the roof renovation and solar requirement together from the start
Owners replacing roofing or waterproofing in Lucerne in 2026 should integrate on-site electricity generation into the project from the beginning. The obligation does not cover every repair and does not automatically require full roof coverage.
The decisive factors are eligible roof sections, solar suitability, building or heritage constraints and the EN-204-LU proof. Early coordination helps avoid redesigning the roof and the solar system later.
UrbanHome · Switzerland
Search properties in Switzerland on UrbanHome
Compare current properties and, when considering an older house, check the roof condition, renovation needs and possible energy-law obligations before buying.
LuzernSolar 2026UrbanHome