Product(s):	OpenBuildings Energy Simulator
	Version(s):	CONNECT Edition
	Area:	Part L

Overview

Criterion 2 of the BRUKL compliance report considers the operation of the building fabric - flagging in red any figures that exceed the allowed maximums - i.e. Ua-calc > Ua-limit.

However it is possible to have surface U-values that exceed the stated maximums, but do not flag a warning.

Method

In cases such as this, all the U-values of windows in the room are being considered. The values for Ua-calc are calculated by the SBEM calculation engine using an area-weighted average method. Therefore, if glazing with the high U-value only accounts for a  small percentage of the overall glazed area of the room(s) then it will have a minimal impact in the final result.

The glazing with the highest U-value is still shown in the Ui-calc column.