When applicable variables change during the performance period, these changes must be recorded on Portfolio Manager to ensure accurate benchmarking of the building. When making updates to the space characteristics on Portfolio Manager, make sure to select “update” rather than “correct” and note the date when the updated space characteristic was first true. By selecting “update” the change in the building characteristic is only counted for the appropriate portion of the performance period rather than the whole thing. For example if 20% of the building space becomes vacant half way through the performance period, update the vacant space on Portfolio Manager so that the building was 100% occupied for half of the performance period and 80% occupied for the other half. In these circumstances, it is a good idea to provide a copy of the “Revision History” for affected spaces along with the prerequisite submittal.