Roman Babakin - stock.adobe.com - Roman Babakinthe essentials in brief
- The CO2Since 2023, costs have been shared between landlords and tenants.
- The amount of the landlord's share depends on the CO2-Emission from the building.
- The worse the energy efficiency, the higher the landlord's share.
- The GModG introduces new classifications for heating systems installed after July 29, 2026.
Anyone operating an apartment building with gas or oil heating will encounter CO2 emissions issues.2The cost-sharing issue is not over. While previously the tenants alone bore the CO2 costs...2Previously, landlords and tenants bore the cost of the energy price through their heating bills; since 2023, these costs have been shared between landlords and tenants. The legislator's aim is to ensure that both sides contribute to climate costs while simultaneously creating incentives for energy-efficient renovations.
Meanwhile, the CO2Cost allocation is standard practice in every heating bill. However, many questions remain in practice. Which buildings are affected? How does the tiered model work? Who calculates the landlord's share? And what special regulations apply to district heating, heat pumps, or individual gas boilers? This blog post answers the most important questions and shows step by step how the CO₂2Cost sharing works in practice.
What is the CO2-Cost sharing?
The CO2The Cost Sharing Act regulates how the costs of national CO2The cost is divided between landlord and tenant. For residential buildings, the landlord's share depends on the CO₂ level.2-Emissions of the building. The worse the energy efficiency, the higher the landlord's share of the costs.
For which buildings and heating media does the CO2 regulation apply?2-Cost sharing?
| regulation | |
| residential building | 10-stage model |
| Non-residential buildings | A flat-rate 50/50 split; a separate statutory tiered model was planned for 2025, but has not yet been implemented. |
| Historical monument | The CO₂ rule also applies to listed buildings.2-Cost Sharing Act. If historic preservation significantly restricts energy-saving measures, the landlord's share is usually halved. |
| Homeowners association | The CO2The cost-sharing law does not apply to condominium owners' associations as such, but rather to rental agreements between landlords and tenants. If a condominium is rented out, the respective condominium owner must pay the legally stipulated landlord's share of the costs.2-Costs to be borne. In practice, this share is often shown in the individual statement of accounts for condominium owners' associations and subsequently taken into account by the landlord towards their tenant. |
| Mixed-use buildings | Heating costs are always billed as a whole (per heating system). Landlords must choose one method: For residential buildings, the allocation is based on a tiered model. For non-residential buildings, the CO₂ is...2The cost share is to be split equally. A non-residential building is a building that is not predominantly (50%) used for residential purposes. |
| Gas heating | Tenant's right to reimbursement; the tenant must assert their claim independently. |
| Heat pump | Typically no direct CO2-Cost allocation according to CO2KostAufG indirect CO2 Costs in the electricity price are not relevant |
| pellet heating | Typically no direct CO2-Cost sharing according to CO2KostAufG |
| District heating | Basically into the CO2Cost sharing is included. The calculation is based on the emission factors provided by the utility company. If a building was first connected to the heat supply network after January 01, 2023, then... CO2 Costs Up not to be applied. |
Who pays how much? The 10-step model explained simply.
The CO2Cost allocation for residential buildings is based on a legally defined 10-stage model. The basis for this is the annual CO₂ emissions.2-Emissions of the building in kilograms per square meter of living space.
basic principle
- low CO2-Emission → high proportion of tenants
- high CO2-Emission → high landlord share
Logic of the model
The model is based on a simple system:
- The CO2-The total emissions of the building are expressed as a proportion of the building's surface area.
- This results in an efficiency value (kg CO₂).2 per m² and year)
- This value determines the classification into a legally defined category.
- The stage defines the percentage distribution of CO₂2-Costs between landlord and tenant
Important classification
- The classification into residential and non-residential buildings is based on the predominant use (>50%).
- The decisive factor is always the entire building, not the individual apartment.
- The calculation is based on actual energy consumption.
- The classification is usually carried out by the metering service provider as part of the heating cost billing.
- The goal is a more equitable distribution of CO2 emissions.2-Costs between operation and use
New rules on CO2-Cost sharing from 2028 onwards
The Building Modernization Act (GModG) of July 23, 2026 also introduced the CO2The cost-sharing law has been amended. The following are affected: Gas, oil and liquefied petroleum gas heating systems newly installed after July 29, 2026Existing facilities continue to enjoy grandfathered rights and remain under the current tiered model.
What exactly is changing?
1. CO2-Costs: Flat rate 50/50 instead of tiered model
The following applies to newly installed gas/oil/liquid gas heating systems from 01 January 2028 The previous tiered model (distribution based on the building's energy efficiency) is no longer in place. Instead, landlords and tenants will share the CO₂ costs.2-Costs are split equally.
2. Gas network charges will become a new billing item.
From January 01, 2028, gas network charges must also be shown separately in the heating bill – and will likewise be split equally between landlord and tenant. This item was not previously included in the heating bill.
3. Obligation to increase the share of climate-friendly fuels
Anyone installing a new gas/oil/liquefied petroleum gas (LPG) heating system will have to use an increasing proportion of biomethane, bio-oil or (green/blue/orange/turquoise) hydrogen from 2029 onwards:
| From year | minimum share |
| 2029 | 10% |
| 2030 | 15% |
| 2035 | 30% |
| 2040 | 60% |
4. Additional costs for the climate-friendly component: split equally – but capped.
The Additional costsThe additional costs resulting from the mandatory biofuel/hydrogen share compared to fossil fuels are also split equally between landlord and tenant – but only up to a fuel share of maximum 30%. For the share above 30% (i.e., only relevant from the 60% level in 2040), the law no longer provides for a 50% split.
5. New hardship clause for landlords
Small landlords (max. 6 apartments) can be exempt from the 50/50 cost sharing requirement under certain conditions – for example, low rent (below 85% of the comparable rent), poor building energy efficiency rating (G/H), and economic hardship. Several cumulative conditions apply.
6. New information obligations
Landlords will in future be required to inform tenants in writing about:
- the obligation to use climate-friendly fuels,
- a possible claim for reimbursement in the case of self-sufficiency in heat,
- the existence of hardship conditions.
This is how the CO2-Costs calculated
- The basis for this is the information provided by the energy supplier. This supplier specifies fuel consumption and CO₂ emissions.2-Emissions or the required emission factors.
- The CO2The building's emissions are allocated to the living space. This results in the CO2 emissions in kilograms per square meter per year.
- This value is used to classify the applicant into the legally defined 10-level model.
- The CO2Costs are divided between landlord and tenant according to the respective level.
How is the CO2 billing handled?2-Cost?
In practice, the billing depends on the heating system. There are two typical cases:
Legally compliant heating cost billing
Brunata Minol takes the CO2Cost allocation is automatically included in your heating bill. Request a free, no-obligation quote now.
Author
André Eichler | Produkt- und Projektmanager Submetering Minol Messtechnik W. Lehmann GmbH & Co. KG
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