PV funding for roof renovation in Aargau

The funding logic starts with the building envelope, not PV alone. Aargau’s 2026 programme funds insulation of roofs and walls or floors against the ground at CHF 40/m², and exterior wall insulation at CHF 60/m². The PV bonus is added only when this envelope refurbishment is eligible.

The system type determines the supplement. The programme lists CHF 20/m² for a greened flat roof, CHF 30/m² for a roof-mounted system on a pitched roof and CHF 100/m² for an in-roof or facade system. These amounts are the PV supplement and do not replace the separate insulation grant.

The area quota must match the reference area. On flat roofs, the bonus requires at least 50% of the eligible roof area and greening. For pitched roofs and facades, at least 70% of the eligible area must be covered; each roof surface is assessed separately by orientation.

Building age and the element involved limit the standard case. Eligible buildings have a building-permit year before 2000 and generally contain building elements that were already heated in the initial state; new additions, extensions and extra storeys are not eligible. For non-residential buildings, the PV bonus is also limited to a maximum of 300 m² of eligible roof area. Protected elements may receive U-value relief where technical impossibility is evidenced.

Technical evidence determines whether the envelope work qualifies. Roofs require a U-value of no more than 0.20 W/(m²K), while walls and floors more than 2 m below ground require no more than 0.25 W/(m²K); exterior walls also use 0.20 W/(m²K). The improvement must be at least 0.07 W/(m²K). From a CHF 10,000 grant, the canton requires a GEAK Plus or an eligible building analysis.

Timing and documents are part of eligibility. The complete application must be received before construction starts; under the general conditions, processing takes four to six weeks. A funding decision is valid for two years, and the canton does not pay grants below CHF 2,000. As a general rule, the limit per building, project or funding item is CHF 50,000 and no more than 50% of eligible investment costs; larger grants are possible only case by case. Planning must therefore start before the PV installation date alone.