# Exit discharge through open, but covered, parking lot



## archclem (Mar 1, 2017)

We are designing a 4 story multi-family project with 2 interior exit stairways in 2 hour rated shafts. One of the stairways "discharges" into a covered parking lot which is open on three sides. The lot in this case is covered by the building. It is separated from the building by a 2 hour rated wall on the fourth side and 2 hour rated floor assembly above the lot. The lot is at grade. Can the occupants access the public way through this parking lot?


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## cda (Mar 1, 2017)

Welcome

Which building code and edition??


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## cda (Mar 1, 2017)

archclem said:


> We are designing a 4 story multi-family project with 2 interior exit stairways in 2 hour rated shafts. One of the stairways "discharges" into a covered parking lot which is open on three sides. The lot in this case is covered by the building. It is separated from the building by a 2 hour rated wall on the fourth side and 2 hour rated floor assembly above the lot. The lot is at grade. Can the occupants access the public way through this parking lot?




Hum

My first thought is you are in a two rated enclosure. You are supposed to maintain that rating till you get out.
But once you go through the two hour wall,you are in another building 


If you are in the lot where is the code compliant exit?


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## archclem (Mar 2, 2017)

2012 IBC

Yes, the stairway is a 2 hour rated enclosure and the parking lot is separated from the building by 2 hour assemblies. Are you suggesting that the parking lot is another building? It doesn't meet the definitions for either habitable or occupiable spaces.


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## steveray (Mar 2, 2017)

Yes.....but the details may be of some debate....


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## cda (Mar 2, 2017)

archclem said:


> 2012 IBC
> 
> Yes, the stairway is a 2 hour rated enclosure and the parking lot is separated from the building by 2 hour assemblies. Are you suggesting that the parking lot is another building? It doesn't meet the definitions for either habitable or occupiable spaces.




Yes technically you have two buildings.

Plus, what  I was trying to say normally once you are in a rated enclosure, that rated enclosure is supposed to continue till outside the building.

Not dump into an area with less than the enclosure rating, such as a lobby or parking garage


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## archclem (Mar 2, 2017)

Okay, that is sensible. Do you have specific references in the codes?


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## cda (Mar 2, 2017)

Yep

Which building code and edition??


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## archclem (Mar 2, 2017)

I assume you are referencing 1003.6 Means of egress continuity


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## cda (Mar 2, 2017)

Found corridor continuity
1020.6 IBC 2015

Plus

1028.5


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## cda (Mar 2, 2017)

*[A] PUBLIC WAY. *A street, alley or other parcel of land open to the outside air leading to a street, that has been deeded, dedicated or otherwise permanently appropriated to the public for public use and which has a clear width and height of not less than 10 feet (3048 mm).


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## cda (Mar 2, 2017)

1003.6 kind of says it also


There are also requirements for garage exiting use itself, will have to find that.

Plus other people will chime in today


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## cda (Mar 2, 2017)

1003.6 kind of says it also


There are also requirements for garage exiting use itself, will have to find that.

Plus other people will chime in


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## RLGA (Mar 2, 2017)

When you leave an exit, you're technically in the portion of the means of egress called the "exit discharge," which you've correctly called it; thus, we should look in Section 1027 for direction and guidance. Exception 1 of Section 1027.1 states that 50% (one exit in your case) is permitted to egress through areas on the level of exit discharge if the three conditions listed are met: (1) The path from exit enclosure to exterior exit door is readily visible and identifiable, (2) the entire area is separated from areas below by a fire-resistance rating equal to the enclosure, and (3) the path from the exit enclosure to the exterior is protected by a sprinkler system.

For condition 1, the entire area is open, so the path to the exit should be visible and identifiable upon exiting the enclosure. For condition 2, if the parking is at grade, then this is a moot issue. For condition 3, since this is a residential building, it is required to be sprinklered, so this should be covered.


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## cda (Mar 2, 2017)

Thank you RGLA

How about since it is not at a public way yet??

And he does not say if the garage is sprinkled


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## RLGA (Mar 2, 2017)

cda said:


> Thank you RGLA
> 
> How about since it is not at a public way yet??
> 
> And he does not say if the garage is sprinkled


Rarely does a building open directly onto a public way. The exit discharge is still from the exit enclosure, beyond the perimeter of the building to the public way. A path must be provided of width complying with Chapter 10; thus, the occupants should not be required to filter through the parked cars to get out beyond the building.

Since the building contains a Group R fire area, the building must be sprinklered throughout per Section 903.2.8, which includes the associated parking area that is covered by the building.


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## cda (Mar 2, 2017)

RGLA 
One last one

The two hour enclosure rating does not have to be maintained all the way

Or does the two hour building wall negate that ?


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## RLGA (Mar 2, 2017)

The stairway enclosure is required to be 2-hour fire barriers, but the rest of the building is not, unless if there was enclosed space below the level of exit discharge. If there were enclosed space below, then a 2-hour horizontal assembly is required between the level of exit discharge and the enclosed space underneath.


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## ADAguy (Mar 2, 2017)

Excellent clarifications of an often confusing issue, thanks RLGA


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## Yikes (Mar 2, 2017)

In addition to the analysis by RLGA, there is another way to think about it.  "A covered parking lot which is open on three sides" = an S-2 open parking garage

Restate the question like this: "Can a means of egress for an apartment building discharge into a parking garage?"  Now I'm picturing residents exiting from their dwelling units, through a corridor, down a 2-hour stairwell, and into a garage where multiple cars are on fire, and intuitively I'm getting nervous.

That said, it is possible that with just one stairway is going into the garage, it might qualify as a type of "horizontal exit" per 1026.  You would need an area of refuge equivalent to the total occupants served by the staircase, but that's probably achievable within the drive aisles of the garage.  

The part that makes me nervous is a bunch of people rushing down this stair, they get to the ground level door, sense the fire on the other side, and now they have to go back upstairs (against all the other people pushing behind them) to find the other exits.


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## RLGA (Mar 2, 2017)

Now picture this, occupants exiting their spaces, through a corridor, down a 2-hour stairwell, and into a lobby that is on fire -- similar scenario; however, this same egress condition exists in many residential and office buildings. 

Parking structures have an inherently good track record regarding fire events (i.e., they catch fire very rarely). Since a lobby is enclosed, smoke can be trapped within the space. On the other hand, in an open parking garage (assuming the openings meet the required areas) the accumulation of smoke will likely be less of an issue than within an enclosed lobby.


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## ADAguy (Mar 2, 2017)

Ouch, serious concerns and possibilities but shouldn't fire sprinklers control the fire in a garage, unless an EQ has disabled them.


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## Francis Vineyard (Mar 2, 2017)

*406.5 Open parking garages. *Studies and tests of fires in open parking garages have shown that, in addition to a low fire loading, the potential for a large fire is exceedingly remote. Based on this data, the IBC establishes special provisions for open parking garages in this section, which in general are less restrictive than those for enclosed parking structures addressed in Section 406.6. The key is that the open parking garage is well ventilated naturally, and as a result, the products of combustion dissipate rapidly and do not contribute to the spread of fire.

*1028.3 Exit discharge components. *The general concept of the exit discharge portion of the means of egress is that the components be sufficiently open to the exterior to prevent the accumulation of smoke and toxic gases. As occupants reach the exterior of the building at grade level, they expect to have arrived at a point of relative safety. Where adequate natural cross ventilation is available to disperse any smoke or gases that may be present, one of the major fire- and life-safety concerns is assumed to have been addressed. It is common that roofed areas be provided at the exterior side of exterior exit doors in order to provide weather protection and/or decoration. Such areas are typically considered as a portion of the exit discharge where they are adequately open on the sides to provide for adequate natural ventilation.

Source 2015 IBC Handbook


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## cda (Mar 2, 2017)

Yikes said:


> In addition to the analysis by RLGA, there is another way to think about it.  "A covered parking lot which is open on three sides" = an S-2 open parking garage
> 
> Restate the question like this: "Can a means of egress for an apartment building discharge into a parking garage?"  Now I'm picturing residents exiting from their dwelling units, through a corridor, down a 2-hour stairwell, and into a garage where multiple cars are on fire, and intuitively I'm getting nervous.
> 
> ...



Without seeing plans makes it harder

I thought there was a recent thread on slope and other requirements, if a garage was used as exiting???


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## cda (Mar 2, 2017)

Yikes said:


> In addition to the analysis by RLGA, there is another way to think about it.  "A covered parking lot which is open on three sides" = an S-2 open parking garage
> 
> Restate the question like this: "Can a means of egress for an apartment building discharge into a parking garage?"  Now I'm picturing residents exiting from their dwelling units, through a corridor, down a 2-hour stairwell, and into a garage where multiple cars are on fire, and intuitively I'm getting nervous.
> 
> ...





Not much fire


http://abc7.com/news/disneyland-parking-garage-fire-damages-9-cars/1753131/


http://www.ktnv.com/news/fire-in-downtown-las-vegas-parking-garage


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## RLGA (Mar 2, 2017)

According to the U.S. Fire Administration, there is in average of 377,108 fires annually in residential buildings. For detached parking garages (they don't have a category for parking garages within another building use, but I assume it would be similar) the average number of fires annually is 4,425. Fires do start in parking garages, but I'd rather place my chances within a parking garage than within the residential floors.


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## cda (Mar 2, 2017)

RLGA said:


> Now picture this, occupants exiting their spaces, through a corridor, down a 2-hour stairwell, and into a lobby that is on fire -- similar scenario; however, this same egress condition exists in many residential and office buildings.
> 
> Parking structures have an inherently good track record regarding fire events (i.e., they catch fire very rarely). Since a lobby is enclosed, smoke can be trapped within the space. On the other hand, in an open parking garage (assuming the openings meet the required areas) the accumulation of smoke will likely be less of an issue than within an enclosed lobby.



But in """ new construction """",

"""" Now picture this, occupants exiting their spaces, through a corridor, down a 2-hour stairwell, and into a lobby that is on fire -- similar scenario; however, this same egress condition exists in many residential and office buildings.""""

I thought that the lobby had to be two hour rated also????

Yes if it is on fire it is on fire, than you get into stairway reentry, plus you know the lobby is sprinkled for sure, with normally more than one way out.


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## cda (Mar 2, 2017)

ADAguy said:


> Ouch, serious concerns and possibilities but shouldn't fire sprinklers control the fire in a garage, unless an EQ has disabled them.




If the garage is sprinkled, guess Disney and the other one were not


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## RLGA (Mar 2, 2017)

cda said:


> But in """ new construction """",
> 
> """" Now picture this, occupants exiting their spaces, through a corridor, down a 2-hour stairwell, and into a lobby that is on fire -- similar scenario; however, this same egress condition exists in many residential and office buildings.""""
> 
> ...


Nope, lobbies only have to meet the same three conditions that I mentioned above. I'm not sure I understand your last sentence...


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## ADAguy (Mar 2, 2017)

He is referring to recent Disney garage fire in Anahiem.


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## cda (Mar 2, 2017)

RLGA said:


> Nope, lobbies only have to meet the same three conditions that I mentioned above. I'm not sure I understand your last sentence...




Just saying if you open the stairwell door on 1st floor, more than likely would go back up and try to renter 2nd floor and find a different way out.

So where does this requirement end???;;;



Found corridor continuity
1020.6 IBC 2015


I thought I was thaught that say the stairwell is 2 hr and dumps into say first floor corridor.
That first floor corridor has to be 2 hr or at least 1 hr


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## RLGA (Mar 3, 2017)

cda said:


> Just saying if you open the stairwell door on 1st floor, more than likely would go back up and try to renter 2nd floor and find a different way out.
> 
> So where does this requirement end???;;;


They could do the same if the stairway exits into the garage.


cda said:


> Found corridor continuity
> 1020.6 IBC 2015
> 
> 
> ...


Corridors are required to terminate at an exit, but could egress into a lobby. If a stairway cannot reach an exterior exit door (and is not eligible for the exception discussed in this thread), then an exit passageway can extend the stairway enclosure (Exception to Section 1022.3, 2012 IBC). An exit passageway is required to be 1-hour-rated, but if it extends a 2-hour-rated stair enclosure, then the exit passageway must be 2-hour-rated.


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## Sifu (Jan 5, 2022)

Reviving this with a twist.

This is an existing building, proposing an interior remodel without changes to the exiting.  From what I can tell, the second exit from the space goes through the exit enclosure at the stairs, then out to the parking garage, then back into the building across the fire separation and then out the main exit.  I can't seem to find any other exit discharge locations.  The parking garage vehicle access openings are enclosed by roll up security grills.  Can't figure out how this was approved.  I can see how the exit discharge through the garage may have been permitted, but not with the gates.  Maybe the gates were added later, and either missed or unpermitted?  Am I missing something?


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## Sifu (Jan 5, 2022)

Sorry, should have included that this is a two-story multi-tenant building.  1/2 the main floor as S-2, the entire second floor is B.  Apears to be ok as separated mixed use and assume it is fully sprinklered.  Also, would this not exceed the 50% limitation for exit discharge to other than the exterior (2018 IBC 1028)?  So even if a side hinged door was installed in the garage, it is questionable.

This brings up a debate I have faced many times and I am still conflicted by.  If this existing building is not compliant, and never was (19 years old), yet the alterations do not included these issues, does the IEBC excuse it?  Both prescriptive and work area methods specify that the _alterations_ must comply, not the unaltered portions.


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