Regarding the interior light requirements: We have an office building that is not intended to be in use during the 11pm to 5am period, therefore we will have automated controls w/ manual overide and occupancy sensors to turn off the lights during that period.

If a person comes in for an atypical reason and turns on the lights to work during those hours, do we need to have the power reduced by 50%, or is such an atypical event allowable, assuming that our occupancy sensors shut off the lights a half hour after the person leaves?