# Stair egress capacity problem in existing high rise building



## Tim Mailloux (Feb 12, 2018)

I am working on a renovation in an existing high rise, type 2A construction, for a local universities downtown campus. The existing floor plan consists of 5 large classrooms and a couple of small offices and a conference room. We are going to be demolishing one of the classroom and the existing offices and making a new office suite with a mix a new offices and conference rooms to support the remaining (4) classrooms. While our project area is only about half the existing floor plate I have calculated the occupant loads of the entire floor (renovated & non-renovated areas) and the total occupant load is 60 people larger than the existing stairs egress capacity as calculated by current Connecticut Building code.  I have also calculated the occupant load of the existing floor plan with the (5) classrooms and the occupant load calculates out to be 80 people larger than the existing stairs egress capacity as calculated by current Connecticut Building code.


Is there any leeway in the Existing Building code to make the argument that while the proposed occupant load exceeds the existing stair egress capacity, the new occupant load is lower than the existing occupant load thus making a bad situation better, but still not up to code?


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## cda (Feb 12, 2018)

Well

No code section, but the city/ university accepted the exiting as is.

Only thing the occupant load calc originally may have been different than what you calc


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## Sifu (Feb 12, 2018)

That's a tough one.  I face this type of thing very often.  We have a lot of buildings that don't meet the codes under which they were originally constructed.  Mostly, we make them upgrade.......but there are limits to what we make them do.  It really stinks to tell an owner that the building they were told was acceptable really wasn't.  These buildings are the most frustrating set of problems I face on a day to day basis.  I don't know for sure it will help but you might look at the compliance alternatives.  I have only ever had one applicant go that route, and it did give alternatives in his case.


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## cda (Feb 12, 2018)

Tim Mailloux said:


> I am working on a renovation in an existing high rise, type 2A construction, for a local universities downtown campus. The existing floor plan consists of 5 large classrooms and a couple of small offices and a conference room. We are going to be demolishing one of the classroom and the existing offices and making a new office suite with a mix a new offices and conference rooms to support the remaining (4) classrooms. While our project area is only about half the existing floor plate I have calculated the occupant loads of the entire floor (renovated & non-renovated areas) and the total occupant load is 60 people larger than the existing stairs egress capacity as calculated by current Connecticut Building code.  I have also calculated the occupant load of the existing floor plan with the (5) classrooms and the occupant load calculates out to be 80 people larger than the existing stairs egress capacity as calculated by current Connecticut Building code.
> 
> 
> Is there any leeway in the Existing Building code to make the argument that while the proposed occupant load exceeds the existing stair egress capacity, the new occupant load is lower than the existing occupant load thus making a bad situation better, but still not up to code?




If  the stairs get brought up, you can always ask for a smaller assigned occupant load.


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## Tim Mailloux (Feb 12, 2018)

A constant issue I run into here in CT are existing stairs. The model IBC allows for stair egress capacity of .3 inches per person in non sprinklered buildings and a stair egress capacity of .2 inches per person in sprinklered buildings. The state of CT has a code amendment making the stair egress factor .3 inches per person regardless of sprinklers. If I could use the .2 factor from the model IBC I would rarely have this type of issue.


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## Tim Mailloux (Feb 12, 2018)

cda said:


> If  the stairs get brought up, you can always ask for a smaller assigned occupant load.


The CT State Building code doesn't allow for an occupant load lower than calculated by table by table 1004.1.2 to be posted. The occupant load per 1004.1.2 is the minimum occupant load of the room / space. Your occupant load can be higher, but never lower.


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## Tim Mailloux (Feb 12, 2018)

Sifu said:


> but you might look at the compliance alternatives.  I have only ever had one applicant go that route, and it did give alternatives in his case.



I will look into the compliance alternatives. Its been a very long time since I went that route on a project.


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## cda (Feb 12, 2018)

So what year edition of IBC did CT. retitle??


And they took this out

*1004.5Areas without fixed seating.*

*https://codes.iccsafe.org/public/document/IBC2018/chapter-10-means-of-egress*


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## Tim Mailloux (Feb 12, 2018)

cda said:


> So what year edition of IBC did CT. retitle??
> 
> 
> And they took this out
> ...




The 2016 CT State Building Code is based on the 2012 IBC with amendments. CT deleted the exception to 1004.5 that allows the AHJ to assign a lower occupant load than calculated by table 1004.1.2.


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## Francis Vineyard (Feb 12, 2018)

Just asking;
1) the conference rooms are reserved for office and classrooms; thus the occupant will not increase but moves from space to another similarly with school cafet?
2) similarly with schools this is a single tenant space? The provision for Level two (2) means of egress "shall be limited to work areas that include exits or corridors shared by more than one tenant within the work area"

The following (2012) sections can be avoided when the work area is 50% or less:
803.2.2
803.2.3
803.4.1
804.2.1.1
804.4.2
805.4.2.1
805.4.3.1
805.4.4.1
805.5.3.1
805.7.2
805.8.2

There may be other exceptions depending on the work area (see definition limited to the permit).


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## Tim Mailloux (Feb 12, 2018)

Francis Vineyard said:


> Just asking;
> 1) the conference rooms are reserved for office and classrooms; thus the occupant will not increase but moves from space to another similarly with school cafet?
> 2) similarly with schools this is a single tenant space? The provision for Level two (2) means of egress "shall be limited to work areas that include exits or corridors shared by more than one tenant within the work area"
> .



1) what you are referring to here is the concept of Non-simultaneous occupancy, which is not recognized by the IBC or the state of CT. In CT the state building official will only allow Non-simultaneous occupant load calculations to be used for plumbing fixture calculations in certain occupations, but never for life safety.

2. Regardless of the size of the work area I need to prove I can get all the occupants off the floor. Are you saying that as long as a renovation does not exceed 50% of the floor area I could add 200 people to the occupant floor occupant load and wouldn't matter?


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## cda (Feb 12, 2018)

Are you sure you are in the USA

We have rights


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## mtlogcabin (Feb 12, 2018)

So are you using 20 net for the classrooms or something else such as assembly?



Tim Mailloux said:


> The CT State Building code doesn't allow for an occupant load lower than calculated by table by table 1004.1.2 to be posted. The occupant load per 1004.1.2 is the minimum occupant load of the room / space. Your occupant load can be higher, but never lower.



For an existing building the posted OL should be the most restrictive along the egress path not what the room or floor will accommodate based on a supposed use. In your case it is .3 for the size of the existing stairs.
If you check the legacy code the building was built under it was more than likely .3 for stairs back in the day


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## ADAguy (Feb 12, 2018)

Who owns the building, university or private? If university owned it may have some leeway to self determine.


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## Francis Vineyard (Feb 12, 2018)

Tim Mailloux said:


> 1) what you are referring to here is the concept of Non-simultaneous occupancy, which is not recognized by the IBC or the state of CT. In CT the state building official will only allow Non-simultaneous occupant load calculations to be used for plumbing fixture calculations in certain occupations, but never for life safety.
> 
> 2. Regardless of the size of the work area I need to prove I can get all the occupants off the floor. Are you saying that as long as a renovation does not exceed 50% of the floor area I could add 200 people to the occupant floor occupant load and wouldn't matter?


Appreciate learning new words to my nomenclature! How about the exception to 1004.1.2?

Wouldn't that amount of increase be a change of occupancy applicable with Chapter 10?


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## Francis Vineyard (Feb 13, 2018)

Tim Mailloux said:


> The 2016 CT State Building Code is based on the 2012 IBC with amendments. CT deleted the exception to 1004.5 that allows the AHJ to assign a lower occupant load than calculated by table 1004.1.2.


I overlooked this explanation and references between different code editions.

My understanding for providing alteration thresholds before adoption of the IEBC with the prescriptive methods is code officials were inadvertently causing buildings to be limited to repairs or become vacant by requiring the complete structure to comply with the provisions of the current codes for new construction.
This was cost prohibitive and sometimes technically infeasible to allow alterations . 
As mentioned it's often found the existing occupant loads exceed both the current code and the code when the occupancy was first permitted.
And as previously pointed out the current code is limited to the "work area" as applicable.
Depending on the code CT adopted typically should not have to retrofit until it meets a special provision for a change of occupancy.


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## Tim Mailloux (Feb 13, 2018)

Francis Vineyard said:


> I overlooked this explanation and references between different code editions.
> 
> My understanding for providing alteration thresholds before adoption of the IEBC with the prescriptive methods is code officials were inadvertently causing buildings to be limited to repairs or become vacant by requiring the complete structure to comply with the provisions of the current codes for new construction.
> This was cost prohibitive and sometimes technically infeasible to allow alterations .
> ...




Francis, thanks for the explanation.

So what your saying is that as long as there is no change of occupancy to the work area, the new occupant loads are not a factor in egress?

Also, digging deeper into IEBC section 805 Means of egress, that section seems only to apply to multi-tenant floors. My project is a single tenant floor so section 805 does not apply, but section 704 Means of Egress does apply.

*704.1 General*: Alternations shall be done in a manner that maintains the level of protection for the means of egress (could the ICC be any more vague? This leaves a lot open for interpretation).

*704.2 (CT Amendment) Minimum Standards*: in addition to the requirements of this code, means of egress in existing buildings shall meet the requirements of the provisions of Part IV of the CT State Fire Safety code for the proposed occupancy.

Part IV of the CT State Fire Safety code is 2012 NFPA 101 (with CT amendments) and it only applies to buildings built prior to 2005, which is when CT switched from BOCA to the IBC based code. Any buildings built after 2005 (under the IBC based codes) fall under part III of the CT State Fire Safety code witch is the 2012 IFC with CT amendments. Looks like I need to dig into the this a little more.


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## mtlogcabin (Feb 13, 2018)

IEBC
CHAPTER 14
PERFORMANCE COMPLIANCE METHODS

* 1401.2 Applicability.
Structures existing prior to [DATE TO BE INSERTED BY THE JURISDICTION. NOTE: IT IS RECOMMENDED THAT THIS DATE COINCIDE WITH THE EFFECTIVE DATE OF BUILDING CODES WITHIN THE JURISDICTION], in which there is work involving additions, alterations or changes of occupancy shall be made to conform to the requirements of this chapter or the provisions of Chapters 5 through 13. The provisions of Sections 1401.2.1 through 1401.2.5 shall apply to existing occupancies that will continue to be, or are proposed to be, in Groups A, B, E, F, M, R and S. These provisions shall not apply to buildings with occupancies in Group H or I.

We use the adoption date of the 2003 IBC. It works very well with older building and achieving compliance with the "intent" of the code.

*


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## Francis Vineyard (Feb 13, 2018)

*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.


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## Paul Sweet (Feb 13, 2018)

When was it built (or last remodeled), and what code was it built (or remodeled) under?  Were any code modifications granted when it was built or remodeled?


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## Tim Mailloux (Feb 14, 2018)

I reached out to a couple of code consulting experts here in CT to get their take on use of the International Existing Building Code (IEBC) in the state of CT and validate my findings. As we all know the model IEBC is very soft on egress and occupant loads in existing renovated buildings requiring little to no analysis and apparently this was not to The State of CT’s liking. The state of CT amended the IEBC adding section *704.2 Minimum Egress Standards* which states that : _In addition to the Means of Egress requirements of the IEBC, means of egress in existing buildings shall meet the requirements of the provisions of Part IV of the Connecticut State Fire Safety Code. _The state fire code then requires that egress components to be analyzed and occupant loads assigned in the new work areas *AND* the existing un-renovated portion of the building per per the requirements of the State fire code (which is very similar to chapter 10 of the IBC). The existing building must then be analyzed to determine that the existing egress components can accommodate the loads of both the existing and new occupant loads to safely egress all occupants from the building.

In a nut shell renovations to existing buildings are much stricter in CT than in other states.


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## Tim Mailloux (Feb 14, 2018)

Additionally, in the opinion of one of the code consultants I spoke with,  use of IEBC Chapter 14, Performance Compliance Methods, is almost useless here in CT, based on the retroactive requirements of the CT State Fire Safety Code.


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## tmurray (Feb 14, 2018)

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?


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## Tim Mailloux (Feb 14, 2018)

ADAguy said:


> Who owns the building, university or private? If university owned it may have some leeway to self determine.



In this project the university is leasing space in a privately owned building. Additionally here in CT, the model code has been amended to define the AHJ as the State Building Official or State Fire Marshall. The State Building Official and State Fire Marshall are the only persons in the state with authority to interpret the code and grant code modifications. Local officials are limited to code enforcement even though many of them think they have the authority to interpret the code. That is of course until you ask them to put something in writing, which they will then refer you to the state guys.


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## Tim Mailloux (Feb 14, 2018)

tmurray said:


> 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.
> 
> ...



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.


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## RLGA (Mar 4, 2018)

Francis Vineyard said:


> *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*"
> ...



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.


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## steveray (Mar 5, 2018)

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?


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## Tim Mailloux (Mar 14, 2018)

steveray said:


> 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
> ...




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.


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## steveray (Mar 15, 2018)

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


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## Tim Mailloux (Mar 15, 2018)

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:


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.


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.


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