# How are degree days calculated

## Degree day number table

### Degree day number table

According to the heating cost ordinance, the landlord is generally obliged to take an interim reading of the heating cost allocator when there is a change of tenant.

With electronic heat cost allocators, intermediate reading is possible without any problems, as the consumption is shown numerically on the display.

Intermediate readings are more difficult with evaporation devices, since they work with a so-called cold evaporation specification (see also the section on consumption recording). If the interim reading takes place shortly after the start of a new billing period, consumption that is too low is displayed due to the specification. Towards the end of the accounting period, the graduated scale is too imprecise to show a clearly visible change. An intermediate reading is pointless in these cases. In order to distribute the consumption costs more or less fairly between the previous and subsequent tenants, the heating costs ordinance allows the consumption costs to be divided according to the degree day method in these cases.

For more than twenty years, the outside temperature was measured at 7:30 a.m., 2:30 p.m. and 9:30 p.m. at various locations in Germany (Berlin, Hamburg, Cologne and Munich) and the mean daily temperature was calculated. Assuming that on days with an average outside temperature of + 15 ° Celsius and more there is no longer a need for heating, a table was drawn up showing the heating needs for the individual months:

 January 170 shares February 150 shares March 130 shares April 80 shares May 40 shares June, July and August together 40 shares September 30 shares October 80 shares November 120 shares December 160 shares

In total, there are 1000 degree day numbers for twelve months.
To calculate the proportional consumption costs, divide the consumption for twelve months by 1000 degree day figures. The result is then multiplied by the sum of the degree day numbers for the rental period.

The consumption-independent part of the heating costs - usually referred to as basic costs in the heating billing - must always be converted to the pro rata rental period according to the degree day table when changing tenants during the billing period.

In contrast to the heating costs, the hot water costs are not converted according to the degree day table when there is a change of tenant. The hot water costs are converted according to the actual rental period, as the hot water temperature does not depend on the outside temperatures.

### IMPORTANT NOTE:

It goes without saying that the content made available in these texts can only represent a "guideline" and is never a substitute for individual advice. Although we carefully check the accuracy of the information provided, it cannot be ruled out that the case law has changed in one point or another since the text was written. Therefore, never take your own actions without further expert advice, taking into account your own contractual position! Those with no legal knowledge may not rely on the texts published here, nor on newspaper articles, etc. Just as one should not treat a not uncomplicated illness oneself, one should not play "advocate for one's own cause".