Min. egress width requirement comment

[spabilove]

Regarding the previous posting, long story short, I received the comment below.

"Response does not appear to relate to comment. Please see clouded area on sheet LS001 at base of rear stairs. The 2nd floor stairs appear to encroach on the egress path where the 2nd floor converges with the 1st floor.

After speaking with the reviewer he indicated that I need to show the total number of occupants who will pass through the clouded area (48" width). This includes tenants 1-A (total 230 occupants with assembly use), 1-B (200 occupants with assembly use), and the second-floor occupants, divided by 2, resulting in 159.2 occupants as there are additional stairs provided from the second floor.

I calculated that the minimum width requirement is 74.8" based on my calculations: "1A: 115 occupants" + "1B: 100 occupants" + "half of the second-floor total occupants: 159.2 occupants." However, only 48" of width is currently provided.

Is there any way to resolve this issue without revising any plans? If I change the future tenant use for 1-A and 1-B, the total occupant load for these two units would be reduced to half of the current load. Therefore, the required minimum width would end up being only 5" less than what is currently required.

As shown in the plan, it is difficult to revise it due to the ramps existing in front of where the different levels end. Please share your thoughts.

Thank you

 

[Yankee Chronicler]

Please refresh our recollection -- your role is that you are the architect?

Speaking (writing) as a licensed architect who is currently working in code enforcement, my reaction to your post above is that you are acting irresponsibly and unprofessionally by suggesting that you "fix" an obvious design error by changing the occupancy classification. The original proposal (based on the discussion you started back in August) was for all four ground floor tenant spaces to be restaurants. I'm sure you didn't make that up, so presumably that's what the building owner -- your client -- wants to do. Have you discussed with your client the notion of fixing your problem by limiting his options for renting his building in the future?

What do you want to change the prospective occupancies to? Since the egress path past the stair is a horizontal component, the fact or is 0.2" per person. If the width is 48", that path has a capacity of 96 people.

The two spaces, 1-A and 1-B, total 6,402 s.f. If you change the occupancy to Mercantile, the occupant load would be 107 -- still too many people. (If each of the mercantile tenants had significant storage areas, you might make it work.) The best reduction would come from making the spaces Business, which would yield an occupant load of 43 people.

But that severely impacts and restricts the owner's flexibility in who he can rent those spaces to.

After speaking with the reviewer he indicated that I need to show the total number of occupants who will pass through the clouded area (48" width). This includes tenants 1-A (total 230 occupants with assembly use), 1-B (200 occupants with assembly use), and the second-floor occupants, divided by 2, resulting in 159.2 occupants as there are additional stairs provided from the second floor.

In your other thread, I posted the IBC Commentary on converging (cumulative) egress capacity. You do NOT have to add the second floor occupant load to the first floor occupant load at the foot of that stair. The first and second floor are NOT considered to be converging occupant loads at that location. Go back to the other discussion and read it again.

 

[steveray]

Please refresh our recollection -- your role is that you are the architect?

Speaking (writing) as a licensed architect who is currently working in code enforcement, my reaction to your post above is that you are acting irresponsibly and unprofessionally by suggesting that you "fix" an obvious design error by changing the occupancy classification. The original proposal (based on the discussion you started back in August) was for all four ground floor tenant spaces to be restaurants. I'm sure you didn't make that up, so presumably that's what the building owner -- your client -- wants to do. Have you discussed with your client the notion of fixing your problem by limiting his options for renting his building in the future?

What do you want to change the prospective occupancies to? Since the egress path past the stair is a horizontal component, the fact or is 0.2" per person. If the width is 48", that path has a capacity of 96 people.

The two spaces, 1-A and 1-B, total 6,402 s.f. If you change the occupancy to Mercantile, the occupant load would be 107 -- still too many people. (If each of the mercantile tenants had significant storage areas, you might make it work.) The best reduction would come from making the spaces Business, which would yield an occupant load of 43 people.

But that severely impacts and restricts the owner's flexibility in who he can rent those spaces to.



In your other thread, I posted the IBC Commentary on converging (cumulative) egress capacity. You do NOT have to add the second floor occupant load to the first floor occupant load at the foot of that stair. The first and second floor are NOT considered to be converging occupant loads at that location. Go back to the other discussion and read it again.

48" is 240 people.....No?

 

[Yankee Chronicler]

48" is 240 people.....No?

:doh:

I'll never admit that I was a math major ...

Thanks for picking up that blooper.

 

[steveray]

:doh:

I'll never admit that I was a math major ...

Thanks for picking up that blooper.

I just remember that a 32" door (CLEAR) is 160 and work everything from there....

 

[Yikes]

I don't know if your project's jurisdiction allows the stair hand rail extensions to rotate 90 degrees (California does not). Assuming they do, you'll probably end up with about 45" clear maximum, which is good for about 225 people for the handrail on the right (as if seen form descending the stairs). You have 159.2 from the upstairs, leaving only enough width for 65.8 occupants combined from both 50% OL of unit 1A and 50% OL of unit 1B.
You could do a combination of things:
1. Voluntarily reduce some of the calculated occupant of tenant spaces 1A and 1B. Let's face it, a future restaurant will likely have food storage, kitchen, office, etc, that will have a much lower occupant load factor. See the exception in IBC 1004.5 for posting a lower occupant load.
2. Push the stairs further to the right.
3. Push the ramp further to the left, and make up the lost elevation with one more leg:

 

[steveray]

Pretty sure the second floor shouldn't be in play...but maybe I am missing something..

1005.6​

Where the means of egress from stories above and below converge at an intermediate level, the capacity of the means of egress from the point of convergence shall be not less than the largest minimum width or the sum of the required capacities for the stairways or ramps serving the two adjacent stories, whichever is larger.

 

[Yankee Chronicler]

Pretty sure the second floor shouldn't be in play...but maybe I am missing something..

1005.6​

Where the means of egress from stories above and below converge at an intermediate level, the capacity of the means of egress from the point of convergence shall be not less than the largest minimum width or the sum of the required capacities for the stairways or ramps serving the two adjacent stories, whichever is larger.

You are correct. I addressed that in the other thread about this design.