As I mentioned in an update to my previous blog post, the Rand Hall Fine Arts Library project at Cornell is still under plan review and a building permit has not yet been issued. [Updated Feb. 7, 2018. But you would never know that a building permit has not been issued from this headline in the online AAP News from Jan. 25, 2018: “Construction Begins on Mui Ho Fine Arts Library.” In fact, only demolition and site preparation permits have been issued; the application for an actual building permit is still under plan review by the City of Ithaca Building Division.] One of the points of contention is the status of the unenclosed exit access stairway (Stair “B”) in the atrium that I discussed in detail in that same previous blog post. I have just learned that a third Code section is being considered in relation to Stair “B,” the idea being that an unenclosed exit access stair terminating above the level of exit discharge can actually be designated as an enclosed “interior exit stair”—even though it is not actually enclosed. This latest argument is based on Section 1023.2 (Exception #2) in the 2015 Building Code of NYS, which states that the requirement that “Enclosures for interior exit access stairways and ramps shall be constructed as fire barriers… or horizontal assemblies…, or both…” (with fire-resistive ratings of 1 or 2 hours) need not be applied within atriums.
There are at two reasons that this latest attempt to salvage an unsafe and noncompliant design should be rejected.
First, the definition of “interior exit stairway” in Chapter 2 of the 2015 Building Code of NYS states that such a stair “provides for a protected path of egress travel.” This means it must be enclosed. That it must be enclosed is reiterated in Section 1023.1 which states unambiguously that an “Interior exit stairways shall be enclosed and lead directly to the exterior of the building or shall be extended to the exterior of the building with an exit passageway.” Neither of these two Code passages are affected by Exception 2 in Section 1023.2. That exception only affects the required level of protection, and does not state that such stairs can be unenclosed. In other words, an enclosure for an interior exit stair in an atrium need not be constructed as a fire barrier with a 1- or 2-hour fire-resistance rating, but, per Section 1023.1 (which isn’t affected by this exception), it still needs to be enclosed. This enclosure is particularly important for smoke control in the atrium space, even without a fire-resistance rating.
Second, even if the first argument is not accepted, calling this exit access stairway an interior exit stairway is still problematic. The reason is that, per Section 1023.1, stair “B” does not lead “directly to the exterior of the building [nor has it been] extended to the exterior of the building with an exit passageway conforming to the requirements of Section 1024, except as permitted in Section 1028.1.” A proposed designation of Stair “B” as an interior exit stair would not meet the criteria in Section 1028.1 of discharging through areas on the level of exit discharge, since it terminates on the second floor. Thus, an exit passageway connecting the base of this proposed (unenclosed) interior exit stair to the enclosed interior exit stair on the second floor must be provided, and that exit passageway must be enclosed. According to its Chapter 2 definition, such an exit passageway must be “separated from other interior spaces of a building or structure by fire-resistance-rated construction and opening protectives, and [it must provide] for a protected path of egress travel in a horizontal direction to an exit or to the exit discharge.” The Code does not permit an interior exit stair to discharge on a second floor (rather it must terminate on the level of exit discharge), a prohibition that is reiterated in Atrium Section 404.10, which only permits “50 percent of interior exit stairways … to egress through an atrium on the level of exit discharge in accordance with Section 1028.”
So, we’re left with Sections 1006.3 and 1019.3 (see previous blog post), and I’ve already commented on the likely outcome based on the consideration of those two remaining code sections.
See this web page for links to, and summaries of, all my writings on the Fine Arts Library proposal.