Looks at a way to bridge a gap between predicted and actual performance of buildings, and bring together the energy performance certificate (EPC) and display energy certificate (DEC) assessments using the Green Deal Assessment tool for non-domestic buildings, which allows the input of non-standard operating conditions, hours of operation and occupancy patterns. By defining these aspects of the building 'in use', the predicted energy performance of the asset can be brought closer to the in-use reality. The non-domestic Green Deal assessment tool is based on iSBEM (www.ncm-sbem.org.uk) and has the ability to link NDEPCs and DECs.

Simplified Building Energy Model (SBEM) is software tool used to create a non-domestic energy performance certificate (NDEPC). It forms part of DCLG's process for implementing the EU Energy Performance of Buildings Directive (EPBD). An NDEPC can be generated using the tool iSBEM, which is the free downloadable user interface for SBEM (www.ncm.bre.co.uk).

Operational Rating Calculation (ORCalc) software is used to calculate the operational rating of a building from annual utility consumption. It also produces the DEC and an advisory report providing advice on energy efficiency measures. http://gov.uk/government/publications/display-energy-certificate-software-specification.