• (Edited )

Yes sir, it does.  That is good that you know that as well.

One thing to keep in mind with stairs is that occupant load at the point of egress is not cumulative.  What that means is that, let's say you have a 4-story building, and each story is served by the 4 fire stairs that you gave as an example.  The 1st floor exit door  at each stair does NOT need to accommodate 60" + 60" + 60" + 60" = 240", and that calculation I just did is assuming that each story needs 60" of width.  The 1st floor exit door would only need to accommodate 60".  Now, if you had an upper floor that for some reason had a greater occupant load than the other stories - say that the 3rd floor needs 72" - you would need to base your 1st floor exit door on that worst case scenario.

Hope that helps!

• What is the right occupant load multiplier for the egress stairs? I read 1005.3.1 dedicated to stairs, and it says to multiply the occupant load by 0.3, and in 1005.3.2 it says that all other egress components should use 0.2 per occupant.

• 0.3" is the correct factor.  Stairs have a wider width requirement than other egress components.

• Thanks! Then I think Aleksandar would multiply 1200 occ. by 0.3 to get 360 inches of required staircase egress width. 360 in divided by 4 staircases would give us 90 inches width. We need each staircase to have double swing doors with 48 inches width each.

• Lulia,

You are correct. I was thinking the same thing when I read the original post, and you beat me to it.

Gang Chen, Author, Architect, LEED AP BD+C (GreenExamEducation.com)

• So just to make sure - you would use the .3 multiplier if you were calculating for stairs - but corridors is .2?

• (Edited )

That is correct. See related IBC Section 1005.3.1, Stairway, and Section 1005.3.2, Other egress components, at this link:

https://codes.iccsafe.org/content/IBC2015/chapter-10-means-of-egress

Gang Chen, Author, Architect, LEED AP BD+C (GreenExamEducation.com)

• I know this is a very old post, so not expecting a response, but I don’t understand why you would absolutely need a double swing 48 inch door. If we assume the library is fully sprinklered than the door capacity - other egress component! - would be 1200 x 0.15 = 180/4 = 45 inches. You could have a custom fire door 45 inches wide. Actually, common in some of the buildings I have been on design teams for.