Part 9, 2-storey Office Exiting requirements

[Sashcro]

NBC (National Building Code) is a whole new animal, Canada only. There are very brief comments on shafts. but not a shaft 'section'. I can not find any allowance for two open floors, only that i need 2 exits and they both need to be rated. There are some areas that suggest i can have an opening (interconnected space) but lots of complications unfortunately. So, 3 sets of stairs for a small building like this one is not going to fly.

 

[ADAguy]

Maybe if you place the elevator on an outside wall with 2 doors, one opening to the building and the other opening to the basement. Same with the stairs, basement exits to exterior only with no interconnect to building.

 

[cda]

NBC (National Building Code) is a whole new animal, Canada only. There are very brief comments on shafts. but not a shaft 'section'. I can not find any allowance for two open floors, only that i need 2 exits and they both need to be rated. There are some areas that suggest i can have an opening (interconnected space) but lots of complications unfortunately. So, 3 sets of stairs for a small building like this one is not going to fly.

So is there a section in there covering when shafts have to be rated?

 

[tmurray]

So is there a section in there covering when shafts have to be rated?

We don't have "shafts" we have exit enclosures and vertical service spaces.

Maybe if you place the elevator on an outside wall with 2 doors, one opening to the building and the other opening to the basement. Same with the stairs, basement exits to exterior only with no interconnect to building.

The basement is not the issue. The floor area is what is requiring two exits in this case. In the NBC only storeys between the first storey and the highest storey count in determining building height. The first storey is defined as the lowest storey not have a finished floor elevation of more than 2 meters above grade. So in this scenario, the building is considered to have two storeys. 9.9.8.2.(2)

In the NBC, the floor area is the area on the storey while subtracting exit enclosures and vertical service spaces.

 

[tmurray]

So do you have a shaft section in the code

And no allowance for two floors open??

Do you know what the NBC code is based on?? IBC or 101 or Canada only?

Two open floors would generally be considered an interconnected floor space and only permitted in a fully sprinklered building, There is a possibility for both open and closed mezzanines without sprinkler protection, but they would be restricted to 40% and 10% of the floor area respectively.

The NBC is developed by the Canadian Commission on Building and Fire Codes under the guidance of the National Research Center. There are times when NFPA 101 can be substituted, like in developing occupant loads, as this code is much closer to how ours is developed. IBC is completely out in left field for us, there are sections that are very similar, but other that are completely different.

 

[steveray]

Is sprinklering the building feasible? How much more than second exit? The sprinklers may have a "payback" in lower insurance and future design flexibility....

 

[Sashcro]

Is sprinklering the building feasible? How much more than second exit? The sprinklers may have a "payback" in lower insurance and future design flexibility....

Client is already over budget. If i were to spring that on them, they are likely to pull the plug. I am going to have to keep that in mind next time though. Regardless if sprinklers are required or not, sometimes they can be suggested in the early stages to avoid some of these issues later on.