Thermal insulation in Switzerland: standards, costs and subsidies 2026

Switzerland is one of the European countries with the most ambitious energy renovation targets. Improving the insulation of your building lowers your heating bills, increases comfort and adds value to your property — and may also make you eligible for subsidies through the Buildings Programme and cantonal programmes. This guide covers the applicable standards, the types of insulation, the factors that make costs vary and the support available in French-speaking Switzerland.

Swiss standards for thermal insulation

The SIA 380/1 standard: the basic reference

The SIA 380/1 “Thermal energy in buildings” standard is the central reference for any insulation project in Switzerland. It sets the maximum permitted U-values (thermal transmittance coefficient, in W/(m²·K)) for each type of wall, taking into account the climate zone (the degree-days of the municipality).

In French-speaking Switzerland, most municipalities lie in zone H2 (altitude 400–800 m) or H3 (below 400 m). The target U-values under SIA 380/1 for a renovation (2026 reference values) are as follows:

Indicative SIA 380/1 values for renovation — zone H2/H3, French-speaking Switzerland.

The MINERGIE label

The MINERGIE label is the benchmark energy certification in Switzerland. A renovation that reaches the MINERGIE-Renovation standard often benefits from additional bonuses in cantonal subsidy programmes. The MINERGIE-P (passive) and MINERGIE-A (self-sufficient) labels set even stricter requirements.

Having a renovated building certified MINERGIE carries its own cost (certification fees, checks, documents to provide), but the label may entitle you to additional grants depending on the canton. These costs should be weighed against the available support before deciding.

The CECB: your diagnostic tool

Before planning insulation work, have a Cantonal Energy Certificate for Buildings (CECB) drawn up. This document rates your building from A (very efficient) to G (very energy-hungry) and offers a CECB+ advisory report with the priority measures and the expected savings. Its cost depends on the size of the building and the level of detail required, and it is often partly subsidised.

Types of insulation and cost factors in Switzerland

External facade insulation (ETICS / ITE)

External thermal insulation (ITE, also called ETICS in French or WDVS in German) is the most effective way of renovating a building envelope without losing living space. It involves bonding or fixing insulation boards to the existing facade, then covering them with a finishing render.

What makes the cost of ITE vary in western Switzerland:

• The type of insulation: EPS is generally the most affordable material, mineral wool sits in the middle, and bio-based insulation (wood fibre, natural fibres) is usually the most expensive.
• The thickness needed to reach the target U-value.
• The facade area and its complexity: balconies, window surrounds, corners and plinths require more detailed work.
• Scaffolding, whose cost depends on the height of the building and the accessibility of the site.
• The condition of the substrate: a wall that needs repairing or cleaning before installation increases the preparatory work.
• The choice of finishing render and any special colours.

For a given project, only a quote prepared after a visit to the facade will give you the real cost. Buildings Programme support is then deducted from the investment.

Loft insulation

Insulating non-habitable lofts is one of the most cost-effective measures in terms of the ratio between investment and energy savings. A layer of blown glass wool on the loft floor is a relatively simple intervention, quick to carry out on a clear loft space.

For habitable lofts (insulation between rafters and under sloping ceilings), the work is heavier. The cost depends on the thickness, the technical solution chosen (insulation between rafters, over-rafter sarking, etc.), the interior finish and the accessibility of the roof.

Insulating the floor above a cellar or unheated basement

Insulating the floor of a ground floor above an unheated basement is simple and effective. The standard solution is to fit XPS or PIR boards between the joists or on the underside of the slab. The cost varies with the ceiling height of the cellar, the presence of ducts and pipes to work around, and the type of finish wanted on the underside.

Replacing windows

Windows are often the thermal weak point of buildings constructed before 1990. Good-quality triple glazing achieves U ≤ 0.7 W/(m²·K), compared with 2.5–3.0 for 1980s double glazing. The cost of replacing a window depends on its dimensions, the performance level of the glazing, the frame material (PVC, wood, aluminium) and the finishing work needed around the opening.

Planning an insulation project

Deciding the order of work

An energy renovation is more coherent when it is planned as a whole. Insulating the facade before changing the windows, or the other way round, affects the junctions and the ventilation of the building. An energy adviser or a thermal engineer can suggest a logical order, taking into account the budget and the timing of the subsidies.

Thinking about ventilation and moisture

A better-insulated building is also more airtight. Without sufficient air renewal, indoor humidity can build up and encourage mould. Before the work, check how the home is ventilated and, where necessary, provide controlled ventilation or suitable airing habits.

Avoiding thermal bridges

Thermal bridges (concrete balconies, lintels, slabs that pass through the facade) let heat escape even in a well-insulated building. A good project identifies them at the design stage and provides detailed solutions: thermal breaks, insulation of window reveals, insulation returns.

Comparing several quotes

To compare offers, ask for detailed quotes that specify the type and thickness of the insulation, the target U-value, the scaffolding, the finishes and the junctions. Two quotes are only comparable if they rest on the same technical assumptions.

Insulation subsidies: Buildings Programme and cantonal support

PRONOVO contributions 2026

The Buildings Programme, via PRONOVO AG, supports envelope insulation measures with investment contributions. The measures concerned include:

• Facade insulation (ITE), calculated according to the facade area treated;
• Roof insulation, calculated according to the roof area;
• Insulation of the floor above a cellar;
• Window replacement, according to the glazed area.

The applicable amounts change regularly and differ between cantons: always check the current rates with PRONOVO or the cantonal energy office before drawing up a budget.

Fundamental condition: the application must be submitted before work begins. Work carried out without a prior application cannot receive federal subsidies.

Combining cantonal and federal support

Cantonal support can be combined with federal contributions. In Vaud, the DIREN service may provide top-ups for reaching MINERGIE standards. In Geneva, the OCEN offers bonuses for envelopes achieving U-values well below the regulatory threshold.

The conditions for combining support, the ceilings and the deadlines vary from one canton to another. It is advisable to check the rules in your canton before signing a works contract.

Choosing an insulation company in western Switzerland

For insulation work, check that the company you approach:

• Employs trained insulation fitters (or subcontracts to specialists) and can show references from comparable projects;
• Understands the requirements of the Buildings Programme and can guide you through the procedures;
• Knows the SIA 380/1 standard and can provide a thermal calculation;
• Works with materials that hold approvals (ETA or Swiss equivalents);
• Can provide proof of liability insurance, which you are entitled to request.

To receive proposals from companies in your area, you can describe your project using the site’s quote request form.