When entering lighting calculation information in PartL, the results sometimes differ from the entered figure.
In a number of cases, the SBEM calculation engine makes use of the NCM modeling guide to ensure that data provided to the calculation engine is correct. This can sometimes involve replacing data in the calculation or applying a function to the inputted data to produce more reliable information.
Under these circumstances, the technical guide has this to say about how SBEM handles Lighting Wattage calculations:
Where a full lighting design has been carried out:Use the actual lighting circuit wattage, multiply it by the illuminance level for this zone from the Activity database, divide it by the illuminance level for which the lighting design was carried out, and divide it by the zone area.