Everything within the exterior walls of the data center should be included. That means that any floor area that supports the data center (regardless of whether there is IT equipment) should be included in the main Data Center Gross Floor Area. In our definition of Data Center, we specify that the Gross Floor Area should include all space within the building(s) including raised floor computing space, server rack aisles, storage silos, control console areas, battery rooms, mechanical rooms for cooling equipment, administrative office areas, elevator shafts, stairways, break rooms and restrooms.
The only time to break something out is if there is an entirely separate function in the same building. For example, say a building has two “wings” and in one wing is the data center while the other wing has a sales office for the company with numerous employees working on the sales team. Though physically within one building the sales wing operates completely independently and could be moved to a different building within impacting the data center. This type of independent space should be broken out as a separate Office property use.