Building Codes and Inspections/Can I avoid Sprinklers?
I am working on a 3000 sf, 1-story, type VB, A3 assembly building with an open storage mezzanine (1/3 size of assembly room). Below the mezzanine is catering/storage area serving assembly room. Can I avoid sprinklers by:
1) Adding an exterior egress stair to provide direct exit from mezzanine down to grade so that mezzanine could be considered a level of exit discharge(see 903.2.1.3-3 and 505.2.3-2. (My building is under area and occupancy thresholds for A3 sprinklers)
2) Add 2hr vertical slab to roof fire barrier to create two fire areas: A-3 Assembly separated from S-2 back area (Mezzanine over catering/storage). If I do this can building still be considered a 1-story type VB with no fire rating requirements for rest of structure? Mezz is 1/3 of Assembly area and can be enclosed per 505.2.1 and 505.2.3 Exceptions 2&3
You can so long as the design is code complaint. It is the task of the design professional to determine how to building structure in the most cost effective manner while still being code compliant. The code official should approve the plans so long as they are code compliant, but they don't care how you achieve the end result. There are options available which might have you avoiding the cost of installing a fire suppression system, but possibly at the cost of adding to your building expenses otherwise.
First, you should be in contact with the Building Official in the municipality where the building is located to determine which version of what code regulates construction there, and to see if there are any local amendments to a standard code which might require fire sprinklers regardless of the other code parameters. If that is the case, then code trade-offs won't help you.
You say you're under the area for a fire suppression system requirement. That being the case, you shouldn't need them unless another area of the code requires them.
With regard to the mezzanine, it does not get calculated into the building area or count as an additional story so long as it isn't more than 1/3 the area of the story and has 7 ft above and below it. ('09 IBC). You just have to have the required exits for whatever is up there.
You are under the 12,000 SF where sprinklers are required in an A3 use per [F]903.2.1.3 of the '09 IBC. The accessory use of the food area probably will not require separation if it's less than 10% of the A-3 use on the same story (508.2 of '09 IBC). You could also construct the building to the requirements of the more stringent use requirements. These code sections might not even apply if a different code is law there, so take these code section references as just food for thought.
You have a complicated situation, but it appears at least possible that by proper design, a fire suppression system may not be required. There are so may variables that I'll leave that up to your design professional and code official. (Plan review by internet doesn't work).
Best of luck with your project!