Since 1 September 2022, the canton of Zurich has required a renewable heating system when replacing an oil or gas heating system – in practice mostly a heat pump, alternatively district heating, wood or other recognised solutions. Only those who prove that renewables are technically not possible or cause more than 5 per cent additional cost over the life cycle may stay fossil – and even then only in an energy-efficient building. Existing electric heating systems must be replaced by 2030. (As of: July 2026)
Key points in brief
- Core rule (§ 11 EnerG): when replacing the heat generator in existing buildings, a renewable heating system is mandatory.
- Counted as renewable are, among others, heat pumps, wood heating, solar thermal systems, district heating (at least 70% renewable/waste heat) and biogas solutions (at least 80% over the service life).
- The exception is narrow: technically not possible or more than 5% additional cost over the life cycle – calculated with the official EN-LCC-ZH tool, checked by the municipality.
- Even in the exception case an efficiency hurdle applies: Minergie, GEAK class D or better, built 1990 or later – or defined standard solutions.
- Existing electric heating systems must be replaced by 2030; for genuine hardship cases § 11b EnerG exists.
What has the Energy Act prescribed since 2022?
With the revision of the cantonal Energy Act (in force since 1 September 2022), Zurich has newly regulated heating replacement: anyone replacing the heat generator in an existing building must switch to a renewable system. The date of the permit is what counts – for everything permitted since, the new rules apply without a transition period.
Important for putting it in context: the law does not prohibit the operation of existing oil and gas heating systems. It takes effect only at the moment of replacement – but then it is binding. Anyone who lets their 20-year-old gas heating keep running breaks nothing; anyone who replaces it faces the fork in the road: renewable or proof of exception.
Which systems count as renewable?
| Solution | Condition |
|---|---|
| Heat pump (air, ground probe, water) | recognised – the practical standard |
| Wood heating (pellets, log wood, chips) | recognised |
| Solar thermal system | recognised (mostly as a supplement) |
| District heating connection | at least 70% renewable energy or waste heat |
| Biogas / renewable synthetic fuels | at least 80% renewable share over the heat generator's service life (§ 11a EnerG) |
As of: July 2026, according to publications of the canton of Zurich. What counts is the EnerG and current enforcement practice.
In practice, for a single-family home the choice mostly comes down to the heat pump – how the switch works in concrete terms is shown in Heating replacement: from oil/gas to heat pump, and whether your own house is suited to it is clarified in Heat pump in an older building. The biogas variant sounds temptingly simple but deserves a sober look at the long-term fuel costs and the availability of corresponding supply contracts over the whole service life.
The exception: when may it be fossil again?
The legislator left the door open a crack – but really only a crack. Fossil replacement is allowed for anyone who proves one of the two conditions:
1. Technically not possible: no renewable solution can be realised at the property – a rare case that has to be justified. 2. More than 5% additional cost over the life cycle: what is calculated is not the purchase price but the total cost over the service life – investment, energy, maintenance. For this the canton provides the official Excel tool EN-LCC-ZH; the calculation goes with the application to the municipality, which checks it.
This life-cycle view is the reason the exception rarely applies: fossil systems are cheaper to buy, but over 20 years of fuel costs and CO₂ levy the picture changes markedly – not to mention the funding for the heat pump, which also plays a part in the comparison calculation.
And even those who clear the exception can't just install: the building must be in a decent energy condition – Minergie-certified, GEAK class D or better, built 1990 or later – or defined standard solutions must be implemented (such as a solar system, thermal insulation of windows/facade/roof, heat recovery or a bivalent system). A poorly insulated older building therefore doesn't get off scot-free with fossil.
For genuine hardship cases – for example when the investment is economically unbearable – § 11b EnerG additionally provides a hardship provision.
How does the procedure work in concrete terms?
The path depends on the fork in the road:
- Renewable (normal case): heat pumps go through the notification procedure – since 2023 without a building permit, with a 30-day period for the municipality. The administrative effort is manageable and lies with the specialist company.
- Fossil (exception case): here the application for thermal-engineering installations (WTA) to the municipality is required – including the life-cycle calculation with EN-LCC-ZH and proof of the efficiency prerequisites. The building department checks whether the 5-per-cent hurdle is actually exceeded.
One special case deserves a mention: emergency heating replacement. If the boiler fails in January, there are enforcement routes for interim solutions – but you still shouldn't improvise; involve the municipality and the specialist company immediately. The best protection against this remains planning the replacement before the heating forces it.
Electric heating: the deadline runs until 2030
Often overlooked: the Energy Act doesn't concern only oil and gas. Existing electric heating systems must be replaced by 2030 – the deadline is fixed and drawing closer. Anyone still heating directly with electricity today shouldn't postpone the switch to 2029: demand for installation capacity is likely to rise towards the end of the deadline, and a planned renovation is always cheaper than a rushed one.
What does this mean for your planning?
Three sober conclusions from four years of enforcement practice:
1. Don't count on the exception. The 5-per-cent hurdle is deliberately set high; in the vast majority of single-family homes the heat pump wins the life-cycle calculation anyway. 2. Use the timing. Anyone who plans the replacement rather than suffering it combines cleverly: heat pump plus photovoltaics in the same project saves double building sites and collects the funding in full. 3. Keep deadlines in view: electric heating by 2030, and with every existing fossil heating system ask whether the next defect will become an unplanned replacement.
Since the rules came into force, one worry has proved largely unfounded: that homeowners would be pushed en masse into expensive forced solutions. What we see instead: the life-cycle calculation the law demands is exactly the calculation one should make even without a law – and in the great majority of cases it comes out in favour of the heat pump. It becomes critical almost only where nothing was invested for years and the boiler then fails. The most expensive heating replacement is the unplanned one.
Frequently asked questions
Do I have to replace my working gas heating?
No. The obligation only takes effect when the heat generator is replaced. Existing systems may continue to be operated and also repaired – only replacement is subject to the new rules.
Can I simply install a gas heating again and buy biogas?
Only under the conditions of § 11a EnerG: at least 80 per cent renewable share over the service life, contractually secured. Calculate the fuel costs over 20 years before choosing this path – it's rarely the cheapest.
Who checks the 5-per-cent exception?
The municipality, on the basis of your life-cycle calculation with the official EN-LCC-ZH tool. The burden of proof lies with the building owner.
Does the rule also apply to apartment buildings?
Yes, the replacement obligation applies to existing buildings generally. In apartment buildings especially, starting planning early pays off, because heat distribution, hot water and possibly a ZEV need to be thought through.
What happens if my heating fails in the middle of winter?
For emergencies there are enforcement routes with interim solutions – contact the municipality and specialist company immediately. Better: proactively replace heating systems from about 15 years of operation, before the emergency dictates the schedule.
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Sources: Canton of Zurich (building regulations for buildings & energy; heating-replacement enforcement pages; EN-LCC-ZH), Energy Act of the canton of Zurich (EnerG, §§ 11, 11a, 11b), AWEL.
Last updated: 9 July 2026 · Author: ecoEn editorial team
