More on Floor-to-Floor Height with Access Floors
The opportunity to reduce floor-to-floor height through the use of an access flooring system, as stated in the original article (EBN
, is not exaggerated if you systematically think through the building. Take a six- story office building, for example. Typically, it would have a slab-on-steel structure with a 9’ ceiling, then 6” inches for lights and wiring, 21⁄2” for cabling and sprinklers (with a fair amount of the sprinkler slope in the interstitial space), 14” for ducts, 191⁄2” for steel, and finally 51⁄2” for the slab. This gives a total floor-to-floor height of 12’ 111⁄2”.As an alternative, consider a 12” raised-floor system (for electrical, telecommunications and air distribution) with a 9’ 6” ceiling height (using suspended direct/indirect lighting), 5” for sprinklers and return air, and 101⁄2” for a post-tensioned concrete structure. This system results in a total floor-to-floor height of 11’ 91⁄2”. A concrete structure becomes practical with access flooring, because you no longer have to worry about poke-throughs for wiring, and no one is walking directly on the slab, so sound transmission is no longer a concern. The conventional approach would result in a building of around 77’ 9” that would be subject to high-rise building codes. The latter would produce a building around 70’ 9”, which may not trigger the high-rise code requirements —resulting in a fair amount of savings.
Rocky Mountain Institute
(1998, April 1). More on Floor-to-Floor Height with Access Floors. Retrieved from https://www.buildinggreen.com/op-ed/more-floor-floor-height-access-floors