Area calculation for basic costs in the heating bill

Basic costs in heating bills must be distributed based on uniform floor space. The Heating Costs Ordinance allows for different distribution keys but sets clear requirements for the calculation. Here, landlords can learn how to calculate basic costs in a legally compliant and transparent manner.

What are basic costs in a heating bill?

The heating bill basically consists of two components:

• use costsThese depend on the individual heating behavior of the residents (e.g., measured heat consumption).
• Basic costsThese costs are incurred regardless of actual consumption and are area-related to all users distributed throughout a building.

Basic costs include, for example:

• Heating system maintenance
• operating current
• pro rata depreciation
• other fixed heating cost components

The exact distribution of these costs is regulated by the Heating Costs Ordinance (HKVO).

What does the Heating Costs Ordinance stipulate regarding the distribution of basic costs?

The Heating Costs Ordinance (HKVO) stipulates the following in Sections 7 and 8:

• The share of Basic costs the total costs must between 30% and 50% lie.
• The remainder (i.e., 50% to 70%) must consumption-dependent be distributed.
• For Heating and Warmwater allowed different distribution keys They may be applied – if this is objectively justified.

This flexibility allows the building owner to adapt the billing to structural conditions or user structures.

Which areas are permissible as a distribution scale?

The following options are available for calculating basic costs:

Heating:

• Total living or usable area (m²)
• heated living or usable area (m²)
• total enclosed space (m³)
• heated enclosed space (m³)

Hot water:

• exclusively the Total living or usable area (m²)
   

The owner is free to choose the allocation method. In practice, using the total living or usable area in square meters has become standard, as this is also permissible for hot water. This avoids double calculation of the area, reducing both effort and inquiries from tenants.

Uniformity in crediting

According to the Heating Costs Ordinance, the chosen allocation method must be applied uniformly throughout the entire building . It is not permissible to use the heated area in some apartments and the total living area in others. This would lead to a distorted distribution of costs.

When are areas for basic costs allowed to be adjusted?

In certain cases, an adjustment of the areas is permissible to ensure a fair distribution. DIN 4713 Part 5 is the relevant standard here , which specifies the following cases:

1. Different temperature design

If rooms are heated significantly less (e.g. garages, storage rooms), the allocated areas may be reduced.

For example:

• Temperature design inside the house: 20 °C
• Garage temperature design: 10 °C
  → A reduction is permissible because the deviation is more than 20% (based on the standard outside temperature, e.g., -12 °C). The basic cost share for the 50 m² garage is calculated as follows:

2. Different ceiling heights

If the ceiling height of individual units deviates by more than 20% from the usual height in the building, an adjustment can also be made.

For example:

• Standard ceiling height: 2,40 m
• Commercial space on the ground floor: 3,00 m
  → The difference exceeds 20%, thus justifying an increase. The basic cost share for the 130 m² business is calculated as follows:

What counts as part of the heated area?

A frequent point of contention is the definition of the heated area , especially when this criterion has been chosen for the allocation of basic costs.

The following are considered heated areas:

• Rooms with their own radiator
• indirectly heated rooms (e.g. hallways without radiators, but open to heated rooms)

The following are not included:

• unheated ancillary rooms outside the apartment (e.g. basement, storage rooms)
• Rooms that are heated only by electric radiant heaters – when This does not apply equally to all apartments.

What happens if tenants dispute the stated square footage?

If discrepancies arise regarding the areas billed, the question of the burden of proof often arises. The case law is clear on this point:

• The landlord does not have to prove anything.that the specified areas are correct
• The tenant must prove that the area that's not true

This was confirmed by the Cologne Regional Court (judgment of August 17, 1995, 6 S 526/94) . Provided that the landlord has calculated the areas uniformly and comprehensibly , this is sufficient for billing purposes.

Conclusion: Uniform and traceable surfaces are crucial.

The inclusion of basic costs in the heating bill is only legally sound if:

• a permissible distribution scale will be elected
• this throughout the entire building uniform is applied
• special structural features (e.g. room height, temperature design) must be correctly taken into account.
• the calculation basis documented and, if necessary, verifiable

Recommendations for landlords

• Ideally, use the entire living area as the benchmark – it is simple, permissible, and easy to understand.
• Apply the same method to all units in the building.
• Check for any significant structural differences and clearly document any corrections.
• If you are unsure about calculating the area, consult specialist literature or an expert.
• Communicate the principles applied transparently to tenants to minimize inquiries.