Take B and R-2 to non-separated occupancies?

[KenH]

Hi folks,

I've got an old apartment building where the owner wants to make some updates. Originally a 1964 BOCA type I-B, sprinklered, with primary R-2 occupancy. Virginia USBC 2012.

Currently there is a reception desk in the lobby that the owner wants to enclose with new walls (dashed red lines), combining it with some existing space (solid red lines) that is existing Business occupancy that is a currently Separated from the R-2 with 1-hr walls.

https://www.dropbox.com/s/g564bhmgsetqjwr/WWT lobby plan_reduced.pdf?dl=0

Do you agree that it would be beneficial to have take the B Occupancy to a Non-separated occupancy per 508.3? I'm thinking that would only require a 1/2 hour fire partition (minimum corridor rating per Table 1018.1) instead of a 1-hour separation. That would allow 20-minute fire rated (instead of 45 min.) glazing that passes the hose stream at protected openings, right? I started second-guessing myself and wanted to get some other opinions before we actually order these pricey windows. Please let me know if you have any thoughts and if you see any flaws in my logic or a simpler (cheaper) solution!

Thanks in advance,
Ken

 

[Paul Sweet]

It looks like an accessory occupancy to me.

 

[jpranch]

Sounds like you might have a Live / Work Unit? If it is then you might want to look at IBC Section 419. Hope this helps.

 

[KenH]

Thanks for the replies Paul and JP.

Good point on the Accessory Occupancy - I'm not sure why I didn't start there. I guess I was thinking that it would still require the new wall to be a 1/2 hour rated partition since it's a corridor wall. Or would the minimum corridor ratings of Table 1018.1 not apply if we call the Business area an Accessory Occupancy?

Not a live/work unit although interesting thought. This will be office space for the leasing staff. They're going away from 24-hour concierge service, so they basically want to turn the concierge space into another enclosed office.

Thanks again for the input. All thoughts appreciated!

 

[jpranch]

If the wall creating the corridor is common to the R-2 and business I would say it must be fire rated. Thoughts?

 

[KenH]

That's basically the conclusion I was arriving at but I was hoping there might be an exception or a different way to look at the condition. Yes,the new wall that will be enclosing the Business use is common to the R-2 egress corridor. Accessory Use or Nonseparated approach would work based on the floor areas, but I'd say that the 30-min corridor rating requirement for R-2 in T1018.1 still has to be achieved. So, any glazed openings in the corridor wall need 20-min Rating with hose stream test (way more expensive than I realized!).

Thanks for weighing in again, JP. Curious if others are in agreement, but I'm stuck with rated walls and expensive glass for this new partition.

Cheers!

 

[jpranch]

My pleasure.