Horizontal Exit and first floor exit accessibility

[ElArch]

First Floor Plan
2nd to 4th floor plan

I have a 4 story type VA R-2 building in California. Please see plans above. The building is separated to two buildings. Below are my questions:
1. When I calculate the number of exits, I only need to consider this as one building. Is that correct?
2. I saw a previous project in my office showing the fire door at separation wall as a horizontal exit and showing occupant numbers at that door. Is that a horizontal exit? How to calculate the occupant numbers at that exit. I can't figure out from the previous project and doubt there are problems in that project.
3. Two exits on the first floor has 6.3' grading difference. Do I need to add ramp or platform lift in those two exits? The exits in the left side and main entrance are accessible.

Thanks!

 

[steveray]

Each building needs to be counted on it's own It looks like your firewall needs to be an HE for building B

503.1.2​

Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building where the building height, number of stories of each building and the aggregate building area of the buildings are within the limitations specified in Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building.

If the "plan North" stair is a rated exit enclosure, that can be an AMOE.....

 

[RLGA]

Here is my response:

1. Addressed by @steveray in his post above.
2. The door at the fire wall can be considered a horizontal exit. The occupant load can be whatever you want to assign to it, but the capacity of the door cannot be less than what is needed for the occupant load you have assigned to it. As a horizontal exit, you can only use the door leaf that swings in the direction of egress travel when the occupant load served is 50 or more. Additionally, you have to consider the refuge area on each side of the horizontal exit per Section 1026.4, and that area is based on the capacity of the horizontal exit door or the total occupant load on the other side, whichever is less.
3. Since Building B requires two accessible means of egress (AMOE), the stairs can be considered an AMOE per Section 1009.2. However, you cannot use them if they are exit access stairways because they connect levels within the same story. If the stairs are enclosed as exit stairs, then they need to comply with Sections 1009.3, 1023, and 1123A.

Also, per Section 905.4, subparagraph 2, a Class I standpipe is required on each side of the horizontal exit adjacent to the exit opening.

 

[ElArch]

Here is my response:

1. Addressed by @steveray in his post above.
2. The door at the fire wall can be considered a horizontal exit. The occupant load can be whatever you want to assign to it, but the capacity of the door cannot be less than what is needed for the occupant load you have assigned to it. As a horizontal exit, you can only use the door leaf that swings in the direction of egress travel when the occupant load served is 50 or more. Additionally, you have to consider the refuge area on each side of the horizontal exit per Section 1026.4, and that area is based on the capacity of the horizontal exit door or the total occupant load on the other side, whichever is less.
3. Since Building B requires two accessible means of egress (AMOE), the stairs can be considered an AMOE per Section 1009.2. However, you cannot use them if they are exit access stairways because they connect levels within the same story. If the stairs are enclosed as exit stairs, then they need to comply with Sections 1009.3, 1023, and 1123A.

Also, per Section 905.4, subparagraph 2, a Class I standpipe is required on each side of the horizontal exit adjacent to the exit opening.

For the two accessible AMOE in building B. I believe one is the horizontal exit. In the stair side, can I install a lift next to elevator to go to the lower level of the lobby then get out? Here is the plan:Lift

 

[Yankee Chronicler]

I do not think wheelchair (platform) lifts are allowed as part of a means of egress -- accessible or otherwise. Elevators can be means of egress -- since you have one, why not use it?

 

[ElArch]

I do not think wheelchair (platform) lifts are allowed as part of a means of egress -- accessible or otherwise. Elevators can be means of egress -- since you have one, why not use it?

According to CBC 1009, both elevator and lift can be accessible AMOE with standby power. I used to post a signage next to elevator: "In case of fire, use stair". And I used to add a smoke guard in front of elevator door except in the exit level. If the elevator is an AMOE, I think I still need to add smoke guard and the signage "In case of fire, use stair" in 2nd-4th floor. So wheelchaired people on the first floor can go through elevator to the lower level of lobby and get out. Am I correct?

 

[princeofpen]

Just because you go through a fire wall does not mean you have a horizontal exit. If you are able to go from mid point between the two exits in building B to their discharge point it's just an exit. If you declare it a HE you've got to determine number of occupants and add 3 sq ft per occupant on either side of the door which, in your case, is mainly in building A.