USGBC developed Reduced Occupancy Guidance for buildings that are 50% to 90% occupied (buildings under 50% occupied are not eligible for LEED-EBOM). This document gives the following guidance for IEQc2.4: “The credit performance threshold is based on the fully occupied and partially occupied portions of the building. Any spaces completely vacant or unused throughout the entire performance period make no contribution to the results and may be excluded.”

If the Reduced Occupancy Guidelines don’t apply to your building (e.g. your occupancy rate is 90% or higher), you should still exclude completely vacant or unused space from your calculations.