Mezzanine Area in Unlimited Area Buildings

[jrush]

Is it acceptable to include the area of a mezzanine as part of the floor area in calculations for Aggregate Accessory Occupancy percentages per 508.2.3 to achieve < 10% of the floor area of the story of an unlimited area building?

 

[RLGA]

Section 505.2 states that the area of a mezzanine does not contribute to the building area (except when determining fire area). Thus, the area of a mezzanine in an accessory occupancy would not be included in the 10% limitation for accessory occupancies.

 

[classicT]

I'd say no as well. Agree with Ron.

2021 IBC 505.2 Mezzanines​

A mezzanine or mezzanines in compliance with Section 505.2 shall be considered a portion of the story below. Such mezzanines shall not contribute to either the building area or number of stories as regulated by Section 503.1. The area of the mezzanine shall be included in determining the fire area. The clear height above and below the mezzanine floor construction shall be not less than 7 feet (2134 mm).

508.2.3 Allowable Building Area​

The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies shall not occupy more than 10 percent of the floor area of the story in which they are located and shall not exceed the tabular values for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

 

[steveray]

It wouldn't increase the floor/ building area, but would need to fall below the 10% threshold for the story it is in...

 

[jrush]

I'd say no as well. Agree with Ron.

2021 IBC 505.2 Mezzanines​

A mezzanine or mezzanines in compliance with Section 505.2 shall be considered a portion of the story below. Such mezzanines shall not contribute to either the building area or number of stories as regulated by Section 503.1. The area of the mezzanine shall be included in determining the fire area. The clear height above and below the mezzanine floor construction shall be not less than 7 feet (2134 mm).

508.2.3 Allowable Building Area​

The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies shall not occupy more than 10 percent of the floor area of the story in which they are located and shall not exceed the tabular values for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

So, then a solution would be separate one of the accessory occupancies to get the percentage down as I can't change the type of construction of the original building (2B)? Does that then also mean that I don't have to include the Mezzanine in my plumbing calculations?

 

[jrush]

So, then a solution would be separate one of the accessory occupancies to get the percentage down as I can't change the type of construction of the original building (2B)? Does that then also mean that I don't have to include the Mezzanine in my plumbing calculations?

So this is an Assembly A-3 Occupancy (Fitness Center) and the most logical thing to do would be to separate the Daycare area E occupancy with a small I occupancy for infants. However when I look at Table 508.4 it shows no separation required.

 

[classicT]

Does that then also mean that I don't have to include the Mezzanine in my plumbing calculations?

No, it does not work along that line of thought. Fixture counts are based upon occupant loads, and mezzanines contribute to occupant loading.