Egress balcony crossing imaginary property line

[MAGB]

I am working on a large complex of garden style apartment buildings. An egress balcony connects buildings considered part of the same building per IBC as they are within the allowable height and area. We would like to use the same egress balcony to connect buildings that are considered separate buildings and separated by an imaginary property line. This would effectively bridge the two buildings. I am a uncertain what rating, if any applies to this section of the egress balcony, or if this is even permitted. Part of the purpose of this egress balcony is to eliminate a dead end corridor, so it would be creating a situation where egress could pass from one building to the other. 1021.4 talks about fire separation distance, but measured at right angles from the exterior edge, in this situation there is an imaginary property line perpendicular to the egress balcony, but adjacencies would run parallel to the edge, if that makes sense. The exterior walls of the buildings require a one hour rating. It is type VB construction and the fire separation distance for each building from the imaginary property line is 5'

 

[RLGA]

Is it a bridge connecting two buildings, or is it an egress balcony that crosses where a fire wall is dividing two buildings?

 

[MAGB]

It is a bridge connecting two buildings.

 

[RLGA]

Use Section 3104 for pedestrian walkways. That will give you the requirements for connecting two buildings across a lot line, imaginary or otherwise.

 

[Yikes]

I seem to recall getting approval to do this on a California state project. That was about 20 years ago.
If I recall correctly, DSA required structural separation (with joint covers) on a least one end of the bridge, so that if one building burned down, the other could remain standing.
We had to do a separation there anyway, for seismic reasons.

Sorry, it’s been too long and my memory is fuzzy on this.

 

[MAGB]

Thank you 3104 answered me questions!