Aggregate Accessory Occupancies

[Markmax33]

Can someone confirm that I'm applying the code correctly here?

Example building:

Suppose a building is primarily a business occupancy but has 2 different occupancies with square footages less than 10% of the total floor area on a floor. The two occupancies occupy 6% of the floor each. (not H occupancy or anything with accessory restrictions)

My interpretation:

I assume the term "aggregate accessory occupancies" means we could only use one of the 6% floor areas as accessory because 6% + 6% = 12% which is greater than 10%.

My secondary interpretation:

They meant the aggregate of each accessory occupancy may not exceed 10%. This would allow you to have two 6% accessory occupancies.

The 2009 IBC says:

508.2.1 Area limitations. Aggregate accessory occupancies

shall not occupy more than 10 percent of the building area of

the story in which they are located and shall not exceed the tabular

values in Table 503, without building area increases in

accordance with Section 506 for such accessory occupancies.

The commentary says:

The aggregate area within a story devoted to the occupancies

that are designated as accessory use areas

must not be greater than 10 percent of the area of that

story [see Figure 508.2.1(1)].

The figure doesn't help much because it uses 2 different areas in the building that are the same occupancy.

Thanks for any advice!

 

[JPohling]

good question that could use some clarification. I always keep it less than 10%

 

[steveray]

10% total can be accessory...

 

[hlfireinspector]

An aggregate is a collection of items that are gathered together to form a total quantity.

 

[cburgess]

I've always taken the term "aggregate" in this instance to mean the total of the accessory spaces, so IMO you can't plan on using both as their aggregate total would be over 10%.

 

[Builder Bob]

I have always allowed 10% of the floor space of the building. If the designer is unwilling to show the entire floor plan of the building, then we would limit him to 10 % of the floor space in his tenant up fit. Foe example, a 12,000 SF building would be allowed 1200 SF for accessory uses. A designer brings in a plan set for a tenant upfit for 1/2 of the building and only shows 6,000 SF of floor space. The allowable accessory space would be limited to 600 SF without a full building analysis.... the way to require this is

3403.1 Existing buildings or structures. Additions or alterations to any building or structure shall comply with the requirements of the code for new construction.

***** Additions or alterations shall not be made to an existing building or structure that will cause the existing building or structure to be in violation of any provisions of this code.****