Glossary
Bio-Treppe
Bio-Treppe: The Bio-Treppe (German for 'bio-ladder', § 43 GModG) requires any gas, oil or LPG heating newly installed in an existing German building after 29 July 2026 to produce a rising share of its heat from biomethane, bio-oil, biogenic LPG or hydrogen: 10% from 2029, 15% from 2030, 30% from 2035 and 60% from 2040.
What is the Bio-Treppe?
The Bio-Treppe (bio-ladder) is the rule in the Gebäudemodernisierungsgesetz (Building Modernisation Act) for new fossil heating systems (§ 43 GModG). If a gas, oil or LPG heating is installed in an existing building after 29 July 2026, a rising share of its heat must come from climate-friendly fuels: biomethane, bio-oil, biogenic LPG or green, blue, orange or turquoise hydrogen.
The steps
| From | Minimum share |
|---|---|
| 1 January 2029 | 10% |
| 1 January 2030 | 15% |
| 1 January 2035 | 30% |
| 1 January 2040 | 60% |
Exceptions and alternatives
If an old heating breaks down beyond repair in 2028 and is replaced with a new gas or oil heating, the obligation only starts twelve months after installation. Solar thermal and ventilation with heat recovery count from 2029 to 2034, and a sufficiently powerful heat pump hybrid meets the obligation permanently. In rented homes, the landlord pays half of the cost of the bio share from 2029, up to a share of 30%.
What does it mean for you?
A new gas heating is allowed again, but each step makes it more expensive to run. Whether a heat pump is the better choice depends on the building, energy prices and subsidies. For a first impression of your building, try the Energy Efficiency Quick Check.
This page is for information only and does not replace legal or energy advice.
Frequently asked questions
Bio-Treppe translates as 'bio-ladder' or 'bio-staircase'. It is the step-by-step rule in Germany's Building Modernisation Act (§ 43 GModG) that makes newly installed gas and oil heating systems use a rising share of biomethane, bio-oil or hydrogen from 2029.
No. It only applies to gas, oil and LPG heating systems newly installed in an existing building after 29 July 2026. Systems that were already running before are not affected.
Through a tariff with the required share of biomethane, bio-oil or hydrogen. From 2029 to 2034, a sufficiently large solar thermal system or ventilation with heat recovery also counts. A heat pump hybrid system meets the obligation if the heat pump provides at least 30% (40% in bivalent alternative operation) of the peak-load boiler's output.