Basement Egress?

[ajh-architect]

Working on a 2 story, multi-use, sprinklered building (2,000 SF office space on first floor with 1,500 SF apartment on 2nd floor).
If we add a basement (below the office) -
1) Does it need more than 1 egress stair?
2) Can the stair be external? Ie, you enter from an exterior stair, or do we need an internal stair?
For now, the basement will be unfinished, and perhaps house the mechanical.
Thanks in advance!

 

[Mr. Inspector]

1. no
2. yes and no

 

[mtlogcabin]

Depends on the size of the basement and if the common path of travel is exceeded where two exits will be required. They can both be exterior. Remember if your aggregate floor area of the second floor and basement exceed 3,000 sq ft an elevator may be needed to meet accessibility requirements

 

[ajh-architect]

Depends on the size of the basement and if the common path of travel is exceeded where two exits will be required. They can both be exterior. Remember if your aggregate floor area of the second floor and basement exceed 3,000 sq ft an elevator may be needed to meet accessibility requirements

Thank you! I'm imagining the basement to essentially be the size of the first floor, around 2,000 SF. Seems like the max distance of travel from any point in Basement to exit stair would be 50'. Why would the residence + the basement yield an elevator/accessibility requirement? (They are separated entirely, with no connection between them.)
Also, does a single-family residence above offices have to adhere to ADA? I am currently not allowing for all the clearances...

 

[mtlogcabin]

Why would the residence + the basement yield an elevator/accessibility requirement? (They are separated entirely, with no connection between them.)

A single residence would not be included in the aggregate floor area IMHO
A 40x50 footprint would be a minimum 90 foot common path of travel. The maximum you are permitted in a sprinkled build is 100 feet to single exit
Depending on the build out you could exceed the maximum 100 ft travel distance permitted for one exit in a basement

1017.3 Measurement.
Exit access travel distance shall be measured from the most remote point of each room, area or space along the natural and unobstructed path of horizontal and vertical egress travel to the entrance to an exit.