CO₂ costs: does the landlord pay too? (CO2KostAufG 2026)
CO₂ costs: does the landlord pay too? (CO2KostAufG 2026)
By a 10-step model, the worse the building's energy performance, the larger the landlord's share (§ 5 CO2KostAufG).
Since 1 January 2023 tenants and landlords split the CO₂ costs of heating. The landlord's share runs to 95%. Where the landlord does not apportion it, or does so defectively, you may cut your heating share by 3%.
§ 7 Abs. 4 CO2KostAufGIn 60 seconds
Since 1 January 2023 tenants and landlords must share the CO₂ costs of heating (Kohlendioxidkostenaufteilungsgesetz).
For residential buildings a 10-step model applies (§ 5 CO2KostAufG): the worse the energy performance, the larger the landlord's share, up to 95% from 52 kg CO₂ per square metre per year.
For non-residential buildings the amount is split in half (§ 8 CO2KostAufG).
Where the landlord fails to apportion, or does so without the required information, you may cut your share of the heating costs by 3% (§ 7 Abs. 4 CO2KostAufG): assert it actively and in writing.
As with any operating-cost statement you have twelve months from receipt to object (§ 556 Abs. 3 BGB).
What the law says
Where the landlord fails to apportion the carbon dioxide costs, or does not do so in full, the tenant is entitled to reduce their share of the heating costs in the statement by 3 per cent. Working translation; the German original is the binding text.
The 10-step model for residential buildings (§ 5 CO2KostAufG)
| CO₂ emissions (kg/m²/year) | Tenant's share | Landlord's share |
|---|---|---|
| 52 and above | 5% | 95% |
| 47 to < 52 | 20% | 80% |
| 42 to < 47 | 30% | 70% |
| 37 to < 42 | 40% | 60% |
| 32 to < 37 | 50% | 50% |
| 27 to < 32 | 60% | 40% |
| 22 to < 27 | 70% | 30% |
| 17 to < 22 | 80% | 20% |
| 12 to < 17 | 90% | 10% |
| under 12 | 100% | 0% |
For non-residential buildings the amount is split in half (§ 8 CO2KostAufG).
Check the headline figures of your statement with the free Nebenkosten checker.
What it means for each side
- Look for the apportionment in the heating statement, if it is missing entirely, your right to cut applies.
- Check the CO₂ figure applied and the step assigned.
- Check the landlord's share was actually deducted from your costs.
- Assert the 3% actively and in writing, within the objection period.
- Show the apportionment in the statement and deduct your share.
- Evidence the CO₂ figure you applied.
- Assign the correct step: the worse the building, the larger your share.
- For non-residential buildings the split is in half.
Common mistakes
Mandatory since 2023, if it is missing you may cut by 3%.
A CO₂ figure set too low shifts the burden in the landlord's favour.
The relief then never reaches you.
The 3% under § 7 Abs. 4 CO2KostAufG has to be asserted actively.
What to do next
Look for the CO₂ apportionment in the heating statement.
Check the CO₂ figure in kg/m²/year and match it against the step.
Check the landlord's share was deducted from your costs.
If the apportionment is missing, assert the 3% in writing: within the twelve-month period.
Frequently asked questions
Does my landlord have to contribute to the CO₂ costs?
Yes. Since 1 January 2023 the Kohlendioxidkostenaufteilungsgesetz (CO2KostAufG, the carbon-cost allocation act) requires landlords and tenants to share the CO₂ costs of heating. For residential buildings the share follows a 10-step model (§ 5 CO2KostAufG): the higher the CO₂ emissions per square metre per year, the larger the landlord's share. Up to 95 %. The landlord must calculate this share and deduct it from your costs in the Heizkostenabrechnung (heating-cost statement).
How big is the landlord's share?
It depends on the building's CO₂ emissions per square metre of living space per year. With a very poor energy balance (52 kg CO₂/m²/year and above) the landlord bears 95 % and the tenant only 5 %. For a very efficient building (under 12 kg CO₂/m²/year) the tenant bears 100 % and the landlord 0 %. The remaining eight steps of the 10-step model lie in between (§ 5 CO2KostAufG).
What can I do if my landlord doesn't split the CO₂ costs?
If the landlord fails to bill your share, or does so without the required information, you may reduce the heating-cost share allocated to you by 3 % (§ 7 Abs. 4 CO2KostAufG). The condition is that the landlord did not carry out the split or did not provide the necessary information. Assert the reduction in writing to the landlord.
Where do I find the CO₂ split in my statement?
The split must be shown in your Heizkostenabrechnung or Nebenkostenabrechnung. Typically the billing service states the fuel quantity, the resulting CO₂ costs, the CO₂ emissions per square metre, the applicable step, and the landlord's share that was deducted. If this information is missing entirely, your 3 % reduction right under § 7 Abs. 4 CO2KostAufG applies.
Does this also apply to commercial premises?
Non-residential buildings do not use the 10-step model but (for now) a 50/50 split: tenant and landlord each bear 50 % (§ 8 CO2KostAufG). Agreements requiring the tenant to bear more than 50 % are void. A step model is also due to be introduced for non-residential buildings from 2025.
- CO2KostAufG, full text of the law (gesetze-im-internet.de)
- IVD: allocating CO2 costs between landlord and tenant
This page gives general information as at the date shown. It does not replace legal advice on an individual case.