Distance between exterior walls of the same building

[aztec]

I have a U shaped building. The debate: code apparently regulates how close the exterior walls can be by table 602 of IBC 2006. Table 602, in my opinion, doesn't mean the exterior walls of the same building nor should I draw the imagery lot line. That's for two separate buildings, correct? If I have a B occupancy building on the same lot, the inside space of the U can be 10 feet if I want it to be, correct? I'm trying to find language that tells me how to address exterior walls of the same building on the same lot line. Yes, I have 30' min surrounding my building on all sides. I do have a door entering the little interior court. Any help would be great.

 

[mtlogcabin]

If I am following you correctly there in no distance between the U- prtions of a non-rated building

If you exit through this U-shape it may fall under the definition of a courtyard and would increase your travel distances

 

[aztec]

If I am following you correctly there in no distance between the U- prtions of a non-rated buildingIf you exit through this U-shape it may fall under the definition of a courtyard and would increase your travel distances

Thanks. From what you wrote, I take it that there is no distance REQUIREMENT between the interior courtyard walls. Rtravel distance makes sense. I'll double chek it.

 

[RLGA]

There is no separation distance requirement between the exterior walls of the same building. Table 602 states the fire resistance is based on fire separation distance of an exterior wall.

The definition of fire separation distance has three components that determine where the distance is measured to from the face of the exterior wall:

1. To the closest interior lot line.
   
2. To the centerline of a street, alley, or public way.
   
3. To an imaginary line between two buildings on the same property.
   

With a U-shaped building, you are not measuring between two buildings--only one. Therefore, there is no requirement for fire separation between the two walls of the "court," except if the court is used for egress purposes, then the walls may need to have a fire-resistance rating per Section 1024.5.2 for "egress courts," but only to a height of 10 ft. above the floor of the court. Contrary to what mtlogcabin stated, an egress court is considered part of the "exit discharge" and is not included in the measurement of travel distance.

 

[aztec]

Thanks Ron. Makes a lot of sense.

 

[fatboy]

Agree, you have one building...........

 

[steveray]

Unlimited area building?....Might require 60'.......Just something to look out for....

 

[kilitact]

If the building has fire walls could be considered two buildings.

 

[RLGA]

Kilitact:

You're correct--"it could be..."

Prior to the 2009 IBC, the requirements in the fire wall section provided for means of terminating fire walls at exterior walls. However, since a fire wall creates two buildings, many jurisdictions apply the requirements for buildings on the same lot (e.g. Section 704.3, 2006 IBC) to the two "buildings," which could logically be interpreted that way.

In the 2009 and 2012 IBC editions, the requirements for fire walls clarified the termination requirements for fire walls at exterior walls. Those editions include two options:

1. The first is to use the method that has been present in the IBC in previous editions.
   
2. The second is to extend an imaginary lot line from the end of the fire wall and treat the exterior walls according to the opening and exterior wall protection requirements of the IBC based on fire separation distance.
   

Thus, it appears that the IBC editions prior to the 2009 edition did not intend to require both the fire wall termination at exterior wall requirements AND the imaginary lot line application. Maybe they did originally intend that, but later determined that it was excessive and decided to approve the use of one method or the other.

 

[Coug Dad]

The 2000 IBC had had a requirement to draw an assumed property line through courts to determine facing exterior wall fire resistive and opening requirements. These requirements were similar to what was in the legacy UBC. Those provisions were removed in the 2003 edition.

 

[aztec]

The 2000 IBC had had a requirement to draw an assumed property line through courts to determine facing exterior wall fire resistive and opening requirements. These requirements were similar to what was in the legacy UBC. Those provisions were removed in the 2003 edition.

That's very interesting. Never heard of that. Just out of curiosity, in the U shaped building example, if one side of the court were say H3 occupancy and the other was B, are you stating in 2006 IBC THE INTERIOR court walls are not regulated? If they are greater than 10' apart, it appears no protection is required. But what about egress courtyard: looks like there isn't any issue. Something seems odd though- no regulation between the walls because it's the same building? There nothing that talks about the occupancy group. Seems strange though....