In a comment to my last post on new code requirements allowing occupied roofs, Bill Johns of the Los Angeles Fire Department (LAFD) reminded me that an occupied roof is required to comply with the exiting requirements of Chapter 10 of the Building Code and a minimum 6'-0" wide, non-vegetated Fire Department access around the perimeter edge is required for both occupied and unoccupied rooftop gardens.
Occupied Roof Exiting
Section 1004.7 of the 2019 California Building Code (CBC) requires occupied roofs accessible and usable by the building occupants to be provided with means of egress as required by Chapter 10 of the CBC.
A summary of the general exiting requirements that apply to a Group A assembly use with loose tables and chairs located on the roof of a building protected throughout by a sprinkler system best illustrates the applicable exiting requirements:
6'-0" Non-Vegetated Fire Department Access at Rooftop Garden Perimeters
For both occupied and unoccupied rooftop gardens in the City of Los Angeles, a minimum 6'-0" wide, non-vegetated Fire Department access around the perimeter edge is required for both occupied and unoccupied rooftop gardens. This requirement comes from the Los Angeles Department of Building and Safety Information Bulletin P/BC 2017-126.
Our understanding of the intent of the 6'-0" perimeter roof edge access around both occupied and unoccupied rooftop gardens is to provide the Fire Department with sufficient unobstructed area at the roof edge to facilitate hand-ladder or aerial ladder operations.
For rooftop gardens with perimeter edges not located parallel and adjacent a roadway or street that can accommodate an aerial (ladder) fire truck, the 6'-0" non-vegetated Fire Department access around the perimeter edge is not required since the aerial ladder cannot reach these areas. Lower roof decks may be accessible to hand ladders and not require a street. These lower rooftop garden areas should be reviewed with LAFD Fire Development Service Section to determine the need for the 6'-0" Fire Department access at the perimeter edge of the lower roof deck.
Applying the New Occupied Roof Provisions
While the new Building Code allows occupied roofs to be located above the building construction story limit for the rooftop occupancy, the exiting requirements of the CBC need to be evaluated for the roof area and local policy requirements such as LAFD's requirement for a 6'-0" non-vegetated Fire Department access around the perimeter roof edge need to be implemented to achieve a successful design for both occupants and emergency responders.
