Abstract
It is often necessary to select the best performing lift installation in terms of energy efficiency, for example, to gain the first credit in the BREEAM classification system1. Previous energy consumption calculation methods have been inaccurate such as that suggested in CIBSE Guide D: 2010 [2]. A more accurate method has been developed by an International Standards Organisation Working Group (ISO/TC178/WG10) and this was published in ISO/DIS 25745-2 [3] on 6 June 2013. A simplified form of the calculation method is given here, together with a more exact method.