Allowable Building Area - Equation 5-2 or Equation 5-3?

[ArtC]

Hello,
I am working on a 3 story Type IIB Self Storage project (S1) occupancy.
1st floor - 32,335 SF of S1 & 956 SF of M Occupancy (It's labeled Office Area per industry convention but it's really a sales area).
2nd Floor - 33,291 SF
3rd Floor - 33,291 SF
Per 508.2.4 of 2021 IBC, Office area can be qualified as accessory to main occupancy ( S1).
What is the correct equation to use? Eq. 5-2 for single occupancy building or Eq. 5-3 for mixed occupancy building?


Thank you in advance.

 

[classicT]

If the M is labeled accessory, then use Equation 5-2. The allowable area of the M occupancy is handled via 508.2.

See the following:

2018 IBC Section 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.​