Where do I find my building's CO2 emissions?

CO2 emissions are listed in your heating cost statement (Heizkostenabrechnung) or the building's energy certificate (Energieausweis). Your landlord or property management is obligated to provide this information. Alternatively, you can calculate CO2 from your consumption (kWh) and fuel type.

Who calculates the CO2 cost split?

Typically the landlord or property management as part of the utility bill (Nebenkostenabrechnung). You can verify the calculation yourself — our calculator helps with that.

Can I challenge the allocation?

Yes. If the CO2 tier was calculated incorrectly or the landlord doesn't perform the split, you can dispute the utility bill. Since 2023, landlords are legally required to allocate CO2 costs.

Does it apply to all heating types?

The 10-step model applies to fossil fuels (gas, oil, coal). District heating (Fernwärme) has simplified rules with a flat 50/50 split. Heat pumps and purely electric heating are not affected.

What about listed buildings (Denkmalschutz)?

Listed buildings or those with renovation restrictions have special rules: the landlord's share is reduced because energy renovation isn't possible. The specific regulations are in the CO2KostAufG.

CO2 Cost Split Germany: Tenant vs. Landlord (10-Step Model)

CO2 Costs in Germany: Who Pays What?

Since January 2023, CO2 costs for fossil heating in Germany are split between tenants and landlords. Before this law, tenants bore the entire burden. Now, the split depends on the building’s energy efficiency — the worse the building, the more the landlord pays.

Sounds fair, but the calculation using the 10-step model is anything but simple. Most tenants don’t know how much they’re actually saving — and many landlords aren’t calculating the split correctly.

In short: CO2 costs are split using a 10-step model: well-insulated buildings (<12 kg CO2/m²) = tenant pays 100%. Poorly insulated buildings (>52 kg CO2/m²) = landlord pays 95%. The CO2 price in 2026 is €55 per tonne.

The 10-Step Model Explained

The split is based on annual CO2 emissions per square metre of living space:

Step	CO2 (kg/m²/year)	Tenant Share	Landlord Share
1	< 12	100%	0%
2	12 – 17	90%	10%
3	17 – 22	80%	20%
4	22 – 27	70%	30%
5	27 – 32	60%	40%
6	32 – 37	50%	50%
7	37 – 42	40%	60%
8	42 – 47	30%	70%
9	47 – 52	20%	80%
10	> 52	5%	95%

Calculation Example: 80 m² Apartment, Gas Heating

Step 1: Calculate CO2 emissions

Gas consumption: 15,000 kWh/year
CO2 factor for gas: 0.202 kg/kWh
Total CO2: 15,000 × 0.202 = 3,030 kg = 3.03 tonnes
Per square metre: 3,030 ÷ 80 = 37.9 kg/m²/year

Step 2: Determine the step

37.9 kg/m² → Step 7 (37-42 kg): Tenant 40%, Landlord 60%

Step 3: Calculate CO2 costs

CO2 price 2026: €55/tonne
Total costs: 3.03 × €55 = €166.65/year

Step 4: Split the costs

Tenant (40%): €66.66/year
Landlord (60%): €99.99/year

Without this law, the tenant would pay the full €166.65 — a saving of €99.99/year.

Calculate Automatically

Calculating with different fuels, apartment sizes, and consumption levels is error-prone. Use our free CO2 Cost Allocation Calculator to determine your share in seconds.

Legal Basis

The Kohlendioxidkostenaufteilungsgesetz (CO2KostAufG — Carbon Dioxide Cost Allocation Act) took effect on 1 January 2023. It applies to all residential buildings with fossil heating.

CO2 Price Development

Year	CO2 Price/Tonne
2024	€45
2025	€50
2026	€55
From 2027	Market price (emissions trading)

Fuel-Specific CO2 Factors

Fuel	CO2 Factor (kg/kWh)
Natural gas	0.202
Heating oil	0.266
LPG	0.237
Hard coal	0.339

District Heating (Fernwärme)

For district heating, a flat 50/50 split between tenant and landlord applies — the 10-step model is not used.

Common Mistakes

Landlord not performing the split — Since 2023, landlords are legally required to allocate CO2 costs. If the split is missing from your utility bill, you have the right to demand a correction.
Wrong square metre figure — CO2 emissions are calculated per m² of living space. An incorrect area shifts the step and changes the split.
Not checking the calculation — Verify your landlord’s CO2 allocation against our calculator. Errors in the step determination are common.
Missing the renovation incentive — Landlords with buildings in steps 7-10 pay the majority of CO2 costs. An energy renovation can quickly pay for itself through lower CO2 contributions.

How Restio Helps

CO2 costs are just one part of your utility expenses — and utility expenses are just one part of your tax situation. Restio helps you keep everything in view:

AI tax expert — ask which utility costs you can deduct on your tax return (craftsman services, household-related services)
Receipt scanning — capture utility bills and craftsman invoices with a photo
Threshold monitoring — the Financial Guardian shows you whether your work-related deductions exceed the lump sum

Try Restio free for 14 days and keep your costs in check.

Conclusion

The CO2 cost allocation provides real relief for tenants — especially in poorly insulated buildings. In a typical 80 m² gas-heated apartment at step 7, the tenant saves roughly €100 per year. The CO2 price rises to €55/tonne in 2026 and will transition to market pricing from 2027. Check your utility bill — the split is mandatory, and many landlords haven’t implemented it correctly yet.