Reader question: Why was my consumption replaced and which comparison basis was used?
Your consumption is listed as “estimated” on the heating cost statement. The word alone does not indicate an error nor a comprehensible calculation. What matters is why proper measurement was not possible, which replacement method was used and how large the affected part of the building was.
Don’t guess the reason
§ 9a paragraph 1 HeizkostenV concerns cases in which consumption cannot be properly recorded because of device failure or other compelling reasons. The regulation lists several bases for the replacement determination: comparable periods of the same rooms, comparable other rooms in the billing period or the average consumption of the building or the user group. [HeizkostenV9a]
Our editorial recommendation: First ask for the documented reason and the period affected. A missed appointment, a failed device and an incorrectly assigned device number are different matters. The article does not confirm that each of these, without further examination, meets the same statutory replacement case. The scope under § 1 must also be appropriate. [HeizkostenV1]
Understand the comparison basis
Ask for an explanation of which of the mentioned methods was actually applied and which data were used. A figure from your own previous year is only understandable as a comparison if the period and rooms are specified. For other comparison rooms, the question is the factual suitability of the basis, not the procurement of unnecessary personal neighbour data.
Place any available device-change or reading documents beside the statement. Ask about deviations instead of equating an earlier device value with a current bill without checking the units. This article is not a technical conversion guide for specific heat cost allocators.
The failure can be a building issue
Paragraph 2 contains a separate consequence if the area affected by the replacement determination or the corresponding room exceeds more than 25 percent of the relevant total size. In that case the provision provides for distribution exclusively according to the criteria specified there. [HeizkostenV9a]
Thus the threshold does not refer to how many of your personal radiators were affected. Have them explain how the building extent was determined. That your individual room is small does not answer whether many other units were affected at the same time.
A fictitious method change
For Tomas, a previous-year comparison was initially stated for one room. In the written explanation a building average is later given. Tomas places both responses side by side and asks which version was actually used and the associated calculation method.
The contradiction does not yet prove a specific excessive amount. However, it is a concrete point to check. The answer should be comprehensible enough to show which value actually affected the bill and whether a correction was made.
Handle objection and payment separately
For inspection of records and objections in residential tenancy relationships, the relevant framework of § 556 BGB must also be observed. [BGB556] Do not rely on an informal enquiry to extend any deadline. If timing is uncertain, bring the bill, the date of receipt and correspondence to legal advice in good time.
A replacement determination is neither rendered unlawful merely by the label “estimate” nor made correct by a professional-looking spreadsheet. Your review needs reason, method, data basis and building extent. With these four points the specific bill can be assessed in a targeted manner.