Large portion of a floor that does not have sufficient clear, unobstructed headroom to conform to local building codes or that has headroom less than that required for occupancy, typically 2.0 to 2.3 m (6.5 to 7.5 ft.). (ASTM Derived from Clear Headroom)
DISCUSSION?Restricted headroom is primarily intended to exclude large areas such as low attics and crawlspaces from being defined as ?floors.? It also establishes, in a sloped ceiling attic or sloped exterior wall, where the effective outer wall is located. Restricted headroom does not apply to reduced or no headroom conditions (i.e. walls, columns, stairs, door headers, limited piping, railings, alcoves, etc.) typically found on a floor, unless they are part of an overall restricted headroom condition.
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