Switzerland has a climate law that does something unusual for climate policy: it pays for the boiler swap instead of putting a price on the oil. Voters accepted the Klima- und Innovationsgesetz on 18 June 2023 (59.1% yes, 42.5% turnout) after the SVP called the referendum. In force since 1 January 2025, its heating-replacement Impulsprogramm runs ten years at about CHF 200 million a year. One year in, there are new building-stock figures to read alongside it.

Two Sundays, one goal

Two years earlier, the tax route lost. On 13 June 2021 the revised CO2 law was rejected with 51.6% no. That evening, environment minister Simonetta Sommaruga called the proposal very extensive, “vermutlich überladen” (probably overloaded). The 2023 result shows what changed. The gfs.bern VOX analysis led by Corina Schena found that two yes-arguments drew 88% agreement each: long-term energy security without fossil fuels, and switching to climate-friendly heating “without new taxes”. FDP supporters moved from 37% yes in 2021 to 66% in 2023, and Mitte supporters from 47% to 64%. The goal stayed the same. The tool changed, and the tool decided the vote.

Then and now

• 2021 (BFS release of October 2022, quoted via a secondary source): 58% of residential buildings heated with fossil fuels (oil 41%, gas 18%), 17% with a heat pump.
• 2025, according to the Federal Statistical Office (BFS) release of 15 September 2026: 50% fossil (oil 33%, gas 17%), 25% heat pumps, and heat pumps in 75% of buildings built in the last decade.

The law cannot take credit for that curve. The Gebäudeprogramm, run jointly by the Confederation and the cantons, has paid for renovations since 2010, and the Impulsprogramm only started in 2025. These figures show a trend the law joined, not one it started.

Year one at the cantonal counter

The Swiss Federal Office of Energy (BFE) reported on 25 August 2026 that the Impulsprogramm received almost 4,800 applications in 2025. About 4,350 projects were committed: 1,936 for the building-envelope bonus and 1,593 for replacing electric heating or heat distribution. Roughly 90% of the 2025 money was used. Together with the Gebäudeprogramm, CHF 636.4 million was committed that year, and 20,097 oil, gas or electric heaters were replaced, 82% of them by heat pumps.

One quiet design choice deserves credit: owners did not have to use a new federal portal. They applied at the cantonal counter they already knew. The people who made year one work are mostly invisible: clerks in cantonal energy offices, Gebäudetechnik planners filling in eligibility forms, and installers fitting heat pumps into cellars built for oil tanks. St. Gallen went further and paid 30% higher subsidies in 2025 and 2026 to help the programme start.

Heat-pump sales fell 30% in 2024 after the 2022–23 boom. Alexandra Märki, CEO of Fachvereinigung Wärmepumpen Schweiz (FWS), argued at the time that heat pumps are currently the only technology able to carry the changeover in heating. In a 2024 statement, Oscar Wahlstrand of GebäudeKlima Schweiz and Meier Tobler said that among heat generators sold, the energy transition had already happened, with eighty percent renewable. On that reading, the 2024 dip was a return to normal sales, not a reversal.

←TODAY: Half of Swiss residential buildings still burn oil or gas, and buildings must cut emissions 82% by 2040 compared with 1990.
→3012: The stock that changed was the stock someone listed, priced and filed for at a counter.
Fulcrum: A subsidy only moves the buildings whose owners apply, so the inventory is the policy.

The trade-off is simple. A levy collects money from every fossil boiler, while a subsidy spends public money and reaches only owners who file an application. The remaining 50% of buildings will not move by themselves. The programme targets systems above 70 kW, electric-heater replacement and envelope work: multi-family blocks, schools and small commercial buildings, exactly the work on a Gebäudetechnik engineer’s desk.

Atelier: For a planning office, this law is a pipeline of renovation briefs that clients have not yet recognised as briefs. The bottleneck is not the technology but knowing which buildings qualify. Monday move: add a “heating above 70 kW, fuel, year installed” column to the office’s project and client register, and assign one person to keep it filled in.

Hack: Estimate how fast the fossil share of the stock is falling, so you can tell a client whether waiting is a plan. The calculation is a straight line between the two BFS data points. It counts buildings, not emissions: a rough clock, not a forecast of the 2040 target.

share_2021, share_2025 = 58, 50                    # % fossil-heated residential buildings, BFS
pace = (share_2021 - share_2025) / (2025 - 2021)   # percentage points per year
print(pace, 2025 + share_2025 / pace)              # 2.0 -> 2050.0 at today's pace

At two points a year, the last oil boiler goes out around 2050, the same year the law sets for net zero, with no margin. From where I write, the decades that went well had one thing in common: the money was there and someone had made the list. List your heaters above 70 kW this month and take them to your canton’s energy office.