AMPHITHEATER, BACK OF HOUSE OCCUPANCY CLASSIFICATION

[archchuck1]

IBC 2021 - OCCUPANCY CLASSIFICATION - WHAT OCCUPANCY CLASSIFICATION WOULD BE CONSIDERED FOR THE BACK OF HOUSE CONSIDERED FOR AN AMPHITHEATER CONTAINING GREENROOMS, STORAGE AREAS, AND A SMALL LOUNGE? THE AMPHITHEATER IN MY OPINION WOULD BE ASSEMBLY, A-5. WOULD THE BACK OF HOUSE BE A-5, B?

 

[fatboy]

Why wouldn't it be an A-1?

303.2 Assembly Group A-1. Group A-1 occupancy includes
assembly uses, usually with fixed seating, intended for the
production and viewing of the performing arts or motion
pictures including, but not limited to:
Motion picture theaters
Symphony and concert halls
Television and radio studios admitting an audience
Theaters

Back of house would be ancillary to the main use?

508.2 Accessory occupancies. Accessory occupancies are
those occupancies that are ancillary to the main occupancy
of the building or portion thereof. Accessory occupancies
shall comply with the provisions of Sections 508.2.1 through
508.2.4.

Just spitballing...

 

[walker.t]

THE AMPHITHEATER IN MY OPINION WOULD BE ASSEMBLY, A-5

I agree with that if you’re talking about a venue that has a stage up front, probably with some sort of roof, with open-air seating for the people watch the activity on stage.

WHAT OCCUPANCY CLASSIFICATION WOULD BE CONSIDERED FOR THE BACK OF HOUSE CONSIDERED FOR AN AMPHITHEATER CONTAINING GREENROOMS, STORAGE AREAS, AND A SMALL LOUNGE?…WOULD THE BACK OF HOUSE BE A-5, B?

Green room: A-3 probably, I think of it as a waiting area where the performers can hang out before or after the show. But if it’s going to be a party room after the show, A-2.
Storage area: A-5, per 2021 IBC 311.1.1 Accessory Storage Areas: “A room or space used for storage purposes that is accessory to another occupancy shall be classified as part of that occupancy.”
Small lounge - A-3 maybe, not sure what you mean by “lounge” and how that’s different than a green room. Can anyone who bought a ticket enter the lounge and hang out? Are snacks and beverages being served there?

I don’t see Group B in anything you’ve described. The back of the house is definitely serving a different purpose than the stage and seating so it must be appropriately classified “based on the nature of the hazards and risks to building occupants generally associated with the intended purpose” (2021 IBC 302.1)

 

[archchuck1]

The following is the attached Life Safety Plan. Thank you for the feedback - much appreciated.

I was classifying most of the back of house as "Group B" Due to IBC 303.1.2


303.1.2 Small Assembly Spaces

The following rooms and spaces shall not be classified as Assembly occupancies:

1. A room or space used for assembly purposes with an occupant load of less than 50 persons and accessory to another occupancy shall be classified as a Group B occupancy or as part of that occupancy.

2. A room or space used for assembly purposes that is less than 750 square feet (70 m2) in area and accessory to another occupancy shall be classified as a Group B occupancy or as part of that occupancy.

I was classifying the stage as "A-5".


303.6 Assembly Group A-5

Group A-5 occupancy includes assembly uses intended for participation in or viewing outdoor activities including, but not limited to:

Amusement park structures
Bleachers
Grandstands
Stadiums


View attachment LS-Amphitheater (jpeg)-min.jpg

 

[fatboy]

Sorry.......shouldn't reply with immediate reaction........."ampitheater" do no register. Disregard (as has happened) my previous reply.

 

[SCBO1]

Wouldn't it be: 302.1 Assembly A-1 (paragraph has "view of the performing arts or motion pictures)

A-5 makes reference to outdoors occupancies

 

[SCBO1]

Sorry, did same thing, didn't pickup on amphitheater

 

[walker.t]

I was classifying most of the back of house as "Group B" Due to IBC 303.1.2

Maybe I’m missing something, but why are you using separated mixed occupancies for this building, doesn’t the building qualify for nonseparated occupancy? Building area is 11,160 s.f., construction type is Type IIB with sprinklers, Table 506.2 allowable area factor for A-5 is unlimited, B is 92,000 s.f. Table 504.3 allowable building height is 75’ for both A and B. So if the entire building is within the more restrictive 92,000 s.f. area limit for Business I don’t know why you’d use separated occupancies. If you used nonseparated occupancy you could get rid of the 1-hour occupancy separation.

Not to step on your toes, but here are a few unsolicited comments on the plan:
1. In the Function of Space color key, “Business” is misspelled.
2. On the plan, you show two blue notes that read “Business (Group B)”, in Point 1 in the code review notes you only list Assembly A-5. You later go on to mention separated occupancies, so I would have thought you would have listed Group B under Point 1 as well.
3. In the two wheelchair accessible stalls, the door should be placed diagonally opposite the toilet per dimensions in A117.1-2017 Table 604.9.3.1.
4. Regarding the three-compartment sink, health department where I work requires drain boards on both ends of the sink, might want to confirm what your health department requires, might be different if it’s only a warming kitchen.
5. For the transfer showers, confirm you have adequate floor space beyond the seat wall per A117.1-2017 608.2.1.2, looks a little tight.