If a building’s original lighting design is available, and there is no discrepancy between that and the observedlighting within the building, the wattage and lux values, from that design, should be entered using the ‘Fulllighting design carried out’ option in SBEM. If complimentary values are not available (i.e. both values fromthe same lighting design) the lighting design(s) must not be used.
If the circuit wattage and lux levels can be accurately recorded by the assessor (see ‘Use of Lux LevelMeters 7.02’) the option for ‘Full lighting design carried out’ should also be used and the appropriate valuesentered. Wattage and lux values must not be entered separately nor is it acceptable to input assumed wattage or lux values from BSRIA publications or other reference documents or to accept or use softwaresuggested default value.
If the circuit wattage and lux values cannot be ascertained by either of the above methods it may be possibleto use the ‘Lighting chosen but calculation not carried out’ option where BOTH the lumens per circuit wattage(lm/cw) and light output ratio (LOR) must be entered, The evidence of how any values used have been obtained must be provided in the site notes.
a) If the lm/cw are known for the entire light fitting including the integral lamp(s) or LED chip(s) the LORis 1
b) If the lm/cw are known for the lamp the LOR for the luminaire also must be obtained in order to usethis information; except in the case of directional (downlight type) lamps which are not shielded by theluminaire or behind a diffuser in which case the LOR is 1
c) A “bulb” type lamp is not directional, so the LOR cannot be assumed to be 1 even if the bulb is notwithin a fitting or shade.If none of the above options are applicable the ‘Lighting parameters not available’ option should be chosenand the appropriate lamp type for the zone should be selected. For zones with a mixture of lamp typesplease see ‘Mixed lighting in a zone 7.03’.
If no lamps are present, please see ‘Missing Lamp Selection 7.05’.
Mike Gordon
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