Stairwell Pressurization

[Norm01]

Hello,
I am involved with a renovation to an exisitng 5 storey hospital in Winnipeg, Canada. There is a new 2 storey front entrance going to be constructed and connected to the exisitng hospital. 2 hour rated firewalls will be used between the new entrance and the exisitng building such that the new entrance is considered a separate building from the exisitng hospital. Currently one of the existing pressurized stairwells exits to the outdoors. As part of the renovation the architect is constructing a fire exit cooridor, where the stairwell will exit into (see attached sketch). The stairs access floors above and a basement below.
I am wondering if the entire fire exit corridor will now have to be pressurized as a reult of the new plan?
Is it possible to install a smaller "vestibule" near the sairwell entry so that only the vestibule would need to be pressurized?
I haven't had a lot of experience with this situation before and looking at the NBC it is not clear what the solution should be.
Thanks for any input.

 

[MechEngNCPE]

Is there a problem with pressurizing the corridor? And is the reason for pressurization only to inhibit infiltration, or is it fire code, because you should always pressurize entranceways into a building.

 

[ChasBean1]

If walls of the existing stairwell changed, I’d say re-test and verify performance. With what you show, I’d say don’t worry – there is a stair outlet door; the egress corridor hasn’t a pressure requirement, only the stairwell itself.

 

[Ticao]

@Norm01,seems like you are worrying about corridor pressurization. Take note that stairwell pressurization happens because of Fan to blow air in this stair in event of fire so that this area is free from smoke and can be used as a passage for evacuation.If you are thinking that the stairwell is always pressurize something like the fan always running then you are wrong.The building should have a clear plan for evacuation instead first.