Stair egress capacity problem in existing high rise building

[Tim Mailloux]

My take on it:

It sounds like you are lowering the occupant load from what it is now based on your posts. I'm going to assume that installing another exit will be so costly that the university will abandon this project and not just a slight modification. Based on this, I would approve the change as an improvement to occupant safety.

Can you do a timed egress study to demonstrate that exiting, while not code compliant, will meet the performance of the code? We see these on occasion here in Canada with some older buildings. But then again, we also do occupant loading based on non-simultaneous occupancy.

Where are your industry lobbyists when they are passing these amendments?

Right now I can only see two options that make sense.

1. Is to reach out to the state and request a code modification assigning a maximum occupant loads to the classrooms. This will get the numbers down enough so the existing stairs can handle all the occupants

2. Rework the plan and add add a horizontal exit dividing the floor in two. This would essentially provide 4 exits compared to the existing 2 exits.

 

[RLGA]

701.2 Conformance. An existing building or portion thereof shall not be altered such that the building becomes less safe
than its existing condition.

To reiterate; 'alterations shall not make the existing building less safe than its existing condition"
Comparison is made to the "existing condition" - not something that some past code might have required or "as required under the code in which it was constructed"

Hope the above is helpful with the CT amendments.

FV has quoted the key requirement here. If the altered condition is less noncompliant than the existing condition, then no modification is required to make the situation fully compliant with the current code. If the current occupant load is 80 occupants over what is allowed by the current code and the altered design reduces this to 60 occupants over the current code, then the existing condition has not been made “less safe than its existing condition.” Thus, the current means of egress width is compliant with the IEBC for your proposed occupant load.

 

[steveray]

If it is a violation of the Fire Safety Code, the local FM should have already cited it......Or you could ask him to. Funny thing in CT, Violations of the Fire Code only have to be corrected to the Fire Code, exempt from building...

(Add) 105.1.3 Connecticut State Fire Safety Code abatement. Where conflicts exist between
the requirements of this code and the requirements of Connecticut State Fire Safety Code
abatement orders issued in writing by the local fire marshal with respect to existing buildings, the
requirements of that portion of the Connecticut State Fire Safety Code that regulates existing
buildings shall take precedence.
Exceptions:
1. New fire protection systems shall meet the requirements of Chapter 9 of this code.
2. Electrical work shall meet the requirements of the NFPA 70, National Electrical Code.
3. Structural, plumbing and mechanical work shall conform to the requirements of this
code.

I would have to look at it more closely, but I doubt anything has to be done to the stairs...Who is your consultant? Spiwak? Versteeg?

Or call OSBI/OSFM, they may be helpful as it is sort of a "State" project guessing they are not doing the review though?

 

[Tim Mailloux]

If it is a violation of the Fire Safety Code, the local FM should have already cited it......Or you could ask him to. Funny thing in CT, Violations of the Fire Code only have to be corrected to the Fire Code, exempt from building...

(Add) 105.1.3 Connecticut State Fire Safety Code abatement. Where conflicts exist between
the requirements of this code and the requirements of Connecticut State Fire Safety Code
abatement orders issued in writing by the local fire marshal with respect to existing buildings, the
requirements of that portion of the Connecticut State Fire Safety Code that regulates existing
buildings shall take precedence.
Exceptions:
1. New fire protection systems shall meet the requirements of Chapter 9 of this code.
2. Electrical work shall meet the requirements of the NFPA 70, National Electrical Code.
3. Structural, plumbing and mechanical work shall conform to the requirements of this
code.

I would have to look at it more closely, but I doubt anything has to be done to the stairs...Who is your consultant? Spiwak? Versteeg?

Or call OSBI/OSFM, they may be helpful as it is sort of a "State" project guessing they are not doing the review though?

This has nothing to do with a fire code violation, the IEBC in CT has been tied into and works in conjunction with the CT State Fire Safety code CTSFSC. I have confirmed my reading of the code and work flow with my code consultant B. Spiewak, as well as the State Deputy Building Official and the State Deputy Fire Marshall.

In the model IEBC code, using the work area compliance method there are very few requirements for analyzing existing egress. You look at your project area, say a tenant space in a high rise building and make sure all new work is to code including any new egress components. But the remainder of the floor does not need to be looked at and the general rule of thumb is that as long as you are not making the egress less safe, than you are good to go. The state of Connecticut has amended the IEBC and added section 704.2 Minimum Standards, which kicks you over to the CT State Fire Safety Code (CTSFSC) to analyses the means of egress in existing buildings. Using the IEBC as amended by the state of CT and the CT State Fire Safety Code, below is the work flow for assigning occupant loads and analyzing egress components under the IEBC in the state. This work flow has been confirmed via email by both the State Deputy Building Official and the State Deputy Fire Marshall:

• The renovated tenant space (aka work Area) shall be analyzed for egress and occupant loads as calculated per the current Connecticut State Building code (CTSBC).

• The unrenovated portions of the floor and existing unrenovated tenant spaces on that same floor need to be analyzed for egress and occupant loads either under Part III or Part IV of the CTSFSC (Connecticut State Fire Safety Code) depending on the original date of construction. Building occupied prior to 12/31/2005 fall under part IV of the CTSFSC and Buildings occupied after 12/31/2005 fall under Part III of the CTSFSC.

• You calculate the total occupant load of the entire floor by adding the new occupant load for the renovated project area as calculated per the CTSBC and existing occupant load of the remainder of the floor as calculated per the applicable provisions of the CTSFSC.

• You then analyze the existing capacity of egress components (stairs & doors) per the applicable provisions of the CTSFSC to make sure they can accommodate the total occupant load (new and existing) of the floor.

 

[steveray]

If it is a level 2 alteration or a change of use, it has everything to do with the fire safety code...

(Amd) 805.2 General. The means of egress shall comply with the requirements of this section.
Exception: Where the work area and the means of egress serving it complies with Part
IV of the 2016 Connecticut State Fire Safety Code.

There are certainly requirements in the IEBC that extend outside of the work area such as handrails and lighting:

805.9 Handrails. The requirements of Sections 805.9.1 and
805.9.2 shall apply to handrails from the work area floor to,
and including, the level of exit discharge.

805.7.2 Supplemental requirements for means-of-egress
lighting. Where the work area on any floor exceeds 50 percent
of that floor area, means of egress throughout the floor
shall comply with Section 805.7.1.

You have a choice to meet either IEBC or CSFSC, but what I was saying is that if there is a CSFSC violation, it dopes not have to be "replaced or repaired" to new (IBC per IEBC 801.3) you can meet the minimum of CSFSC on the correction

 

[Tim Mailloux]

I agree with what you have posted, but my original problem is in regards to occupant loads and stair capacity. The model IEBC really doesn’t address how to handle this and basically says that as long as you are not making egress less safe you are ok. But no direction about how to calculate occupant loads for the area of the floor outside of the work area. CT IEBC amendment 704.2 Minimum (Egress) Standards kicks you over to the state fire code to calculate occupant loads and egress capacity of the existing area outside the work area. The intent is to make sure that renovations in the work area do not over populate the entire floor (new work and existing to remain) past what the exits can safely egress. This has been confirmed to me by both the Office of the State Building Official and the Office of the State Fire Marshall, so its really no longer up for debate.


I my particular case I pretty much only have two options open to me:

1. Apply for a code mode to post a maximum occupant load on the 4 remaining classrooms. By calculation each classroom has 88 occupants but the maximum student size is 65 students plus a professor. If I can post a maximum occupant load or 70 persons per classroom that will reduce the floor occupant load by 40 people. Buase this building was constructed prior to 2005 it falls under Part IV (2012 NFPA 101) of the fire code which allows me to use the NFPA enhanced egress calculation for stairs over 44” wide. This calculation gives me an additional 8 persons per stair compared to the standards CTCBS calculation. These two things together will get my occupant load to a point where the 2 existing stairs can handle all the people.

1. Option Two is to split the floor in half with a 2 hour rated horizontal exit with one of the two stairs on either side of the new horizontal exit. IMO this approach is kind of a shell game, but one that is routinely allowed.