Horizontal Exit

[hallro]

Hi all,

Running into some code interpretation challenges and would appreciate your input.

Project Overview:

• 5-story, 19-unit apartment building
• 4 levels of R-2 above 1 level of enclosed carport (U)
• Fully sprinklered (NFPA 13)
• Occupied rooftop terrace
• 2022 California Building Code

Issue:
Per CBC/CFC 1009.2.1, standby power for the elevator is required unless a 2-hour horizontal exit is provided on every floor (excluding the exit discharge level), assuming full sprinklers.

Since the roof is occupied but can’t feasibly include a horizontal exit, does this disqualify the exemption entirely? Or can the exemption still apply to the floors below, thereby avoiding the need for standby power?

I’ve attached a PDF of the plans. Would love any suggestions on whether a horizontal exit can be added with minimal project impact—or if standby power is ultimately unavoidable here.

Thanks in advance for your help!

 

[Yankee Chronicler]

Your plans don't show the roof level. And where's the firewall? I don't see anything on those plans that looks at all like a firewall.

As to the roof -- the model IBC allows exit access travel to include one story of vertical travel. This means if you can meet the maximum exit access travel distance from anywhere on the roof to an exit, you should be able to use the horizontal exit on the upper enclosed story as an exit and still satisfy egress requirements. Does California retain the provisions allowing exit access travel to include exit access stairs?

Not sure if that would resolve the issue anyway.

 

[TheCommish]

I don't think the first story enclosed carport is a u-occupancy it's a parking garage

 

[Yankee Chronicler]

As to the roof -- the model IBC allows exit access travel to include one story of vertical travel. This means if you can meet the maximum exit access travel distance from anywhere on the roof to an exit, you should be able to use the horizontal exit on the upper enclosed story as an exit and still satisfy egress requirements. Does California retain the provisions allowing exit access travel to include exit access stairs?

Not sure if that would resolve the issue anyway.

I just looked up California BC 1009.2.1. Based on that, treating egress from the roof to the fifth floor as exit access rather than exit doesn't resolve the issue. It looks like you need to provide stand-by power for the elevator.