There is more of a requirement for heating in the wintertime than the summertime due to lower outside temperatures. As a result, heating costs in the winter season are higher than in the summer months each year.
If a rental agreement is in place for an entire billing period (January to December of any year), then the heating costs (monthly prepayments) normally even out over the course of the year:
for the months of January to March/April, the heating costs are comparatively high – higher than the monthly advance payment which is based on a yearly average (“degree day figures”).
In the following months, however, consumption is considerably lower due to rising outside temperatures. Your monthly advance payment will therefore be too high by comparison. In general, the level of monthly advance payment remains unchanged within a billing period. But as no heat is used in the summer months, but the same monthly advance payments are made as in the wintertime, the costs for providing heat eventually even out as an annual average.
If you only move into your property in October on a particular year, it is not possible to even the costs out in this way. According to the daily heat cost allocation table, the months of October, November and December are some of the most intensive months of the year for heating. Consequently, the costs for heat consumption during these months exceed the monthly advance payments which have already been calculated based on the consumption during the summertime. This then leads to a back payment.