HOW THE 2019 California Building Code (CBC) MAY IMPACT YOUR HOSPITAL DESIGN.
Part 1: Egress Width Requirements for Stairs and Doors within California Healthcare Facilities
By Steven Dannaway, PE, DBIA – The 2019 California Building Code (CBC) specifies minimum width requirements for egress components in healthcare occupancies and is enforced by the Office of Statewide Health Planning and Development (OSHPD). These requirements are often more restrictive than those encountered in other occupancies. The requirements of the Life Safety Code, NFPA 101 must also be considered, although in many cases the CBC will be more restrictive. The following is a brief discussion on the minimum required egress widths for stairs and doors in Group I-2 and Group I-2.1 occupancies. This is Part 1 of a two-part series. Part 2 covers egress widths for corridors.
Doors: CBC 1010.1.1 requires a minimum clear width of 44 inches for egress doors serving Group I-2 and Group I-2.1 occupancies, where the doors serve areas with bed and stretcher patients. Where a double door is provided and serves as an egress door from Group I-2 occupancies, it has been Coffman’s experience that OSHPD will require at least one individual door leaf to provide a minimum 44-inch clear width and will not permit two 36-inch nominal width doors to satisfy the 44-inch clear width when considered as one aggregate opening. Where egress is required in both directions at a double door location, and the double door serves more than 49 occupants on each side, a set of dual-egress opposite-swinging doors is required, with one door leaf swinging in each direction.
The maximum nominal width of a single door leaf is 48-inches. Doors that do not serve Group I-2 occupancy areas with bed or stretcher patients require a minimum clear width of 32 inches according to CBC 1010.1.1.
Stairways: CBC 1011.2 requires exit stairways in Group I-2 or Group I-2.1 occupancies to provide a clear width of not less than 44-inches. The “clear width” requirement is California added language to Section 1011.2. Upon review of CBC 1014.8, located within the handrail section of Chapter 10 with another California amendment, it is clear that the CBC’s intent is to require the 44-inch clear width dimension for Group I-2 exit stairways between handrails. This is a more restrictive width requirement than what is required for other occupancies, where the minimum required stairway width is measured from stringer-to-stringer.
Note that this 44-inch clear width requirement between handrails is a separate and independent requirement from the required egress width for a stairway’s exit capacity. If a stairway serves 200 occupants, it will require a minimum egress width of 60-inches, at a factor of 0.3 inches/occupant. In this case, the exit capacity requirements will drive the size of the stairway. In the case that the stairway only serves 100 occupants, the stairway would only require a 44-inch width from stringer-to-stringer to satisfy the exit capacity requirements; however, CBC 1011.2 and 1014.8 would still require a minimum 44-inch dimension between handrails.
While CBC 1014.8 does not reference Group I-2.1 occupancies, CBC 1011.2 does include Group I-2.1 occupancies in the requirement for a 44-inch clear width. It is good practice to assume this same requirement applies to ambulatory healthcare facilities.
CBC 1014.7 specifies a minimum dimension of 1.5-inches between the handrail and the wall that it is attached to, whereas the 2012 edition of NFPA 101, 18.104.22.168.4.5 specifies a minimum dimension of 2.25-inches. The prior 2000 edition of NFPA 101 specified a 1.5-inch minimum clearance dimension, same as the CBC. The 2012 edition of NFPA 101 was not adopted by CMS until May 2016; therefore, this conflict would not have been an issue on OSHPD projects prior to this time.
The NFPA 101 and CBC requirements converge in Group I-2 and Group I-2.1 occupancies to necessitate wider stairways than are required in other occupancies. As handrails can project between 2.25-inches to 4.5-inches into the required egress width, the required stairway width can range between 48.5-inches up to 53-inches to satisfy 1) the 44-inch CBC clear width requirement between handrails, and 2) the NFPA 101 minimum clearance of 2.25-inches between wall and handrail. Note that the occupant load served by the stairway may also drive the required egress width of the stairway.
Stay tuned for Part 2 that will highlight egress width requirements for corridors within California healthcare facilities.
Read more Engineering Insights for California Healthcare.