The dormer, with its exact geometric dimensions, can be measured in accordance with DIN EN 12831.
Only the length of the dormer in meters (m) needs to be entered.
In the heating load calculation, an additional 10 W/K per side wall of the dormer is automatically added to the transmission losses. The room volume is increased by 9 m² multiplied by the dormer length as a fixed value.
Source(s): Bosy-Online (accessed 2023), Heating Load Calculation According to DIN 12831
Recknagel (2020): Handbook for Heating and Air Conditioning Technology