Interstitial Floor Area

The area of load-bearing surfaces located above or below occupied building floors that are not available for general occupancy often due to inadequate clear headroom, and contain building mechanical or electrical systems predominantly serving adjacent floors or to provide access to such systems. (ASTM Derived from Interstitial Area) ****** A Unified Approach for Measuring Office Space | For Use in Facility and Property Management : Copyright 2007. Building Owners and Managers Association International and International Facility Management Association. All rights reserved. ISBN # 1-883176-73-5