This question comes from the John Portman thread, but is more focused on the technical aspects of designing a mega-scaled atrium space. Let's say you have a hypothetical project that calls for a 50-story atrium with irregular geometry, along the lines of the Atlanta Marriott Marquis:
Am I correct in thinking that such atrium spaces would now be completely forbidden under IBC unless all the corridors were enclosed with a one-hour rated partition or glazed with deluge sprinklers? Retractable smoke curtains might help meet code in some cases, but they also involve significant design limitations.
I appreciate the need to mitigate smoke travel, but today's code requirements seem like complete overkill. A number of recent overseas projects demonstrate that such atrium spaces are permissible in quite a few overseas jurisdictions. How do these jurisdictions deal with the issue of smoke?
Hypothetically, how would you propose a performance-based solution that meets the goals of IBC's prescriptive mandate, while still maintaining the design intent?
Non Sequitur
Sep 2, 16 10:22 am
How do they deal with smoke? They simply don't is my guess. Sorta like some places allow for horizontal guard rails while I'm stuck with vertical pickets at 4" O.C. eventhough it's only a 18" drop.
I like that picture.
senjohnblutarsky
Sep 2, 16 10:33 am
Uh... the whole horizontal rails thing went away after 2003 IBC. As far as I know, there is nothing prohibiting horizontal rails... Other than our lovely litigious society.
Non Sequitur
Sep 2, 16 10:41 am
I don't deal with IBC, so... horizontal rails are still evil for me.
mightyaa
Sep 2, 16 11:55 am
It's been awhile since I've looked at this, but it is still possible. Smoke evac systems, and rated walls out into the atrium space. Other tricks might be possible like making the glass skylight above operable so you can call it outdoor space and comply with separations and protected openings. Or creating operable horizontal enclosures to compartmentalize every 3 stories. Or various rating systems using area separation walls. It is possible... just a code nightmare. The easiest is to do a fire/smoke study and get the signoff by the CBO as 'equal' (don't forget they can override anything a code book says) I think I remember seeing this is easier under the new 2015 IBC than it has been.
x-jla
Sep 2, 16 12:12 pm
I think the Phoenix public library uses a smoke evac system to make their atrium compliant. Check it out
David Cole, AIA
Sep 2, 16 12:32 pm
mightyaa, I was wondering about the outdoor space option, especially if such a project were located in a mild climate like Southern California. The space would then be considered a courtyard rather than an atrium, with a whole different set of code implications.
This question comes from the John Portman thread, but is more focused on the technical aspects of designing a mega-scaled atrium space. Let's say you have a hypothetical project that calls for a 50-story atrium with irregular geometry, along the lines of the Atlanta Marriott Marquis:
Am I correct in thinking that such atrium spaces would now be completely forbidden under IBC unless all the corridors were enclosed with a one-hour rated partition or glazed with deluge sprinklers? Retractable smoke curtains might help meet code in some cases, but they also involve significant design limitations.
I appreciate the need to mitigate smoke travel, but today's code requirements seem like complete overkill. A number of recent overseas projects demonstrate that such atrium spaces are permissible in quite a few overseas jurisdictions. How do these jurisdictions deal with the issue of smoke?
Hypothetically, how would you propose a performance-based solution that meets the goals of IBC's prescriptive mandate, while still maintaining the design intent?
How do they deal with smoke? They simply don't is my guess. Sorta like some places allow for horizontal guard rails while I'm stuck with vertical pickets at 4" O.C. eventhough it's only a 18" drop.
I like that picture.
Uh... the whole horizontal rails thing went away after 2003 IBC. As far as I know, there is nothing prohibiting horizontal rails... Other than our lovely litigious society.
I don't deal with IBC, so... horizontal rails are still evil for me.
It's been awhile since I've looked at this, but it is still possible. Smoke evac systems, and rated walls out into the atrium space. Other tricks might be possible like making the glass skylight above operable so you can call it outdoor space and comply with separations and protected openings. Or creating operable horizontal enclosures to compartmentalize every 3 stories. Or various rating systems using area separation walls. It is possible... just a code nightmare. The easiest is to do a fire/smoke study and get the signoff by the CBO as 'equal' (don't forget they can override anything a code book says) I think I remember seeing this is easier under the new 2015 IBC than it has been.
I think the Phoenix public library uses a smoke evac system to make their atrium compliant. Check it out
mightyaa, I was wondering about the outdoor space option, especially if such a project were located in a mild climate like Southern California. The space would then be considered a courtyard rather than an atrium, with a whole different set of code implications.