Talking in Code: High-rise building definition
Want to know more about roof truss failures? Have a question about fire-rated assemblies? Confused about safety glazing on windows and door? In our monthly column — Talking in Code — International Code Council code experts will address some of the typical questions asked of our technical services team regarding current code issues. This feature is not an ICC code opinion, nor is it a committee interpretation, but it is intended to provide clarification of code text for adopting jurisdictions, design professionals and members of the construction industry.
International Code: 2015 International Building Code
Question: Is it the intent of the definition for a high-rise building to include an “occupied” roof when evaluating the 75 foot criteria with respect to the lowest level of fire department vehicle access?
Answer: As indicated in the definition for a high-rise building in Section 202 of the 2015 International Building Code (IBC), a building is considered a high-rise when there is an “occupied floor” more than 75 feet above the lowest level of fire department vehicle access. The occupied floor, in this case, was referring to the “occupied floor” of the highest story and not the level of the occupied roof. In general, a floor is a floor and a roof is a roof. Just because a roof is an occupied roof does not make it a floor with respect to the definition of a high-rise building. The code has had provisions related to adequate egress from occupied roofs for years without classifying the roof as an occupancy for purposes of other code issues including height/area limitations, mixed uses, sprinklers or type of construction.
It should be noted, however, that there are new provisions in the 2015 IBC (Section 903.2.1.6) which addresses sprinkler protection due to an occupied roof and in the 2018 IBC (Section 503.1.4) which address occupied roofs based on the floor immediately below the roof. In both cases, if sprinkler protection is provided throughout the building, whether the roof is an occupied roof has no bearing on height/area limitations, occupancy separation requirements or the classification of the building as a high-rise.
As always, code opinions issued by International Code Council staff are based on published Code Council codes and do not include local, state or federal codes; policies; or amendments. This opinion does not imply approval of an equivalency, specific product, specific design or specific installation and cannot be published in any form implying such approval by the International Code Council. As this opinion is only advisory, the final decision is the responsibility of the designated authority charged with the administration and enforcement of this code. All code citations reference the 2015 and 2018 International Codes unless otherwise specified.