Good insulation can reduce a home’s heating costs by up to 60 per cent. In Switzerland, insulating a façade from the outside generally costs between 150 and 300 CHF per m², including installation, and the cantons subsidise part of the work. Here’s where heat escapes, how much each solution costs and how to get help from your canton.
Where does heat escape from?
In a poorly insulated house, heat escapes mainly through the façade and the roof. Approximate figures for heat loss:
| Element | Proportion of heat loss |
|---|---|
| Facade (walls) | approx. 30% |
| Roof | approx. 21% |
| Windows | approx. 12% |
| Basement and ground floor | approx. 11% |
| Inefficient ventilation and heating | approx. 26% |
Source: figures taken from PostFinance.
How much does insulation cost in Switzerland?
Prices depend mainly on the method chosen and the scaffolding, which is often a significant cost. Approximate figures, including installation:
| Work | Approximate price |
|---|---|
| External wall insulation | approx. 150 to 300 CHF/m² |
| Blow-in insulation (cavity walls) | approx. 45 to 120 CHF/m² |
| Roof or top-floor ceiling | Depending on the method: the top-floor ceiling is the cheapest option |
| Ceiling of an unheated cellar | Often the simplest and cheapest solution |
Sources: Neho and PostFinance. These figures vary depending on the canton, town and access to the site: only the quotes are binding.
Solutions, element by element
The façade
- External insulation: the most common and most effective method. It eliminates thermal bridges and does not reduce the living space. It requires scaffolding and often a planning permission, as it alters the building’s appearance.
- Ventilated façade: more expensive, but offers a wider choice of cladding materials (wood, panels, metal).
- Blown-in insulation: quick and inexpensive, provided the wall has an air gap.
- Internal insulation: possible when the exterior cannot be accessed, but it reduces the living space and is less effective at managing damp.
The roof
A pitched roof can be insulated on top of, between or beneath the rafters. If the loft is unoccupied, insulating the ceiling of the top floor is significantly cheaper. The ideal time to do this is when the roof covering needs to be replaced anyway.
The cellar
If the cellar is unheated, insulating its ceiling is usually sufficient. It’s a small, quick job that improves the comfort of the ground-floor rooms.
Which materials should you choose?
- Synthetics (polystyrene, polyisocyanurate): highly insulating despite their thinness.
- Mineral-based (rock wool, glass wool): non-combustible.
- Natural (wood fibre, hemp, cellulose): good for summer comfort, but require a slightly greater thickness.
The method used is more important than the material when it comes to cost. Ask tradespeople to quote for the same thickness and the same performance (U-value) so you can compare.
Insulation grants
Insulation of the building envelope is subsidised by the Buildings Programme, administered by each canton.
- The grant is calculated in francs per square metre of insulation.
- A good performance level must be achieved (U-value of 0.20 or better).
- The application must be made before the work begins, never afterwards.
| Canton | Amount for façade, roof or floor | Main conditions |
|---|---|---|
| Vaud | 40 CHF/m² (U ≤ 0.20) · 70 CHF/m² (U ≤ 0.15) · 100 CHF/m² with solar panels | Buildings granted planning permission before 2000; minimum grant of 3,000 CHF; written approval required before any purchase or work |
| Geneva | 140 CHF/m² for external elements (U < 0.2) · 80 CHF/m² for underground walls and floors | Application must be submitted at least 14 days before work begins |
For other cantons, consult your canton’s energy department or leprogrammebatiments.ch. Your municipality may offer additional funding: see francsenergie.ch. Energy-saving investments may also be tax-deductible, depending on your canton’s regulations.
Example in the canton of Vaud: 120 m² of insulated façade with a U-value of 0.15 entitles you to approximately 120 × 70 = 8,400 CHF.
See the financial support available in your canton →
The stages of an insulation project
- Obtain a CECB (cantonal energy performance certificate): this shows where the house is losing heat and which works are a priority. A CECB Plus is required in the canton of Vaud for grants of CHF 10,000 or more.
- Request quotes for the same thickness and the same U-value.
- Submit the grant application and wait for written approval.
- Obtain planning permission from the local council if the external appearance of the property will change.
- Carry out the work, if possible at the same time as other works (roofing, windows) to share the scaffolding.
- Send the supporting documents to the canton to receive the grant.
Beware of asbestos
In buildings constructed or renovated before 1990, façade materials such as render may contain asbestos. Have an asbestos survey carried out before the work begins (Suva).