Accessory occupancies & multiple bldgs. on a single site

[Redmund]

I am reviewing a project that has four separate Type II-B F-1 occupancy buildings and a single Type V-B U occupancy building on the same single lot. All the buildings are detached from each other, but also close enough to each other that imaginary lot lines would need to be considered between the buildings unless IBC 705.3 exception no. 1 is used.

The designer does want to look to IBC 705.3 excep. 1 to treat all five buildings effectively as a single building, but then wants to take it a step further and say that since the most restrictive allowable area case, the Type V-B U building, has a floor area no more than 10% of the combined area of the four Type II-B F-1 buildings, the most restrictive allowable area case when using IBC 705.3 excep. 1 then becomes the Table 506.2 factor for a Type II-B F-1 building (effectively ignoring the Type V-B U occupancy building when determining the most restrictive allowable area case).

Can the accessory occupancy provision in IBC 508.2.3 be used with IBC 705.3 excep. 1 as the designer is proposing?

 

[Tim Mailloux]

705.3 exception #1 is pretty clear IMO.

Two or more buildings on the same lot shall be either regulated as separate buildings or shall be considered as portions of one building if the aggregate area of such buildings is within the limits specified in Chapter 5 for a single building. Where the buildings contain different occupancy groups or are of different types of construction, the area shall be that allowed for the most restrictive occupancy or construction.

 

[RLGA]

I would say it would be allowed, but not to the extent you described. Section 705.3, Exception 1 states, "within the limits specified in Chapter 5 for a single building." Chapter 5 allows accessory occupancies within a single building. Thus, if the Group U occupancy is less than 10% of the aggregate area of all four buildings, then the Group F-1 becomes the most restrictive occupancy group. However, the Type VB-constructed building is the most restrictive construction type.

Thus, your allowable area would be based on a Type VB, Group F-1 building.

 

[steveray]

I would say it would be allowed, but not to the extent you described. Section 705.3, Exception 1 states, "within the limits specified in Chapter 5 for a single building." Chapter 5 allows accessory occupancies within a single building. Thus, if the Group U occupancy is less than 10% of the aggregate area of all four buildings, then the Group F-1 becomes the most restrictive occupancy group. However, the Type VB-constructed building is the most restrictive construction type.

Thus, your allowable area would be based on a Type VB, Group F-1 building.

Yep…if VB F1 works, they can make it happen…