Single Means of Egress Prevails
Originally built in 1915 and currently housing the San Diego Museum of Man, the California Tower is a part of the Balboa Park National Historic Landmark District. The building stands ten stories above grade and atmospherically connects to the museum space on the first and second floors. The building is non-sprinkler protected Type II-B construction and it did not undergo a change of use for this project.
The tower is provided with a single means of egress from Floors 3-10 an existing historic stair. When Holmes Fire was brought on, the stair comprised non-compliant width and tread depth. As such, the tower did not comply with CBC Section 1021, requiring at least two means of egress. The design team submitted an Application for Use of Alternate Materials and Methods with the City of San Diego utilizing California Historic Building Code. The City requested a timed egress assessment to compare the performance of the proposed single stair with that of a compliant case with two stairs.
Holmes Fire closely collaborated with ARG to successfully demonstrate that emergency egress from the subject building was comparative to a code compliant building. The time associated with occupant emergency movement via stairs was based upon calculations outlined in The SFPE Handbook of Fire Protection Engineering.