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Crawl Space Floor Area

Matthew Burr

Member
Joined
Apr 22, 2016
Messages
5
Location
San Diego
If we used a portion of floor area under a house for mechanical equipment/ plumbing rooms does that area need to be included in gross floor area? This would be a "crawl space" with a max. height of 5'. My boss is sure that we do not need to include this area as part of our total gross floor area. I just can't find any code references to substantiate his claim. I feel like regardless of ceiling height, if you are using a portion of the basement for mechanical space it should be included in the gross area. Any thoughts? Thanks!

This is a single family detached project in California (2013 CBC)
 
I have always looked at whether this is an area that we could turn into livable area easily (ie. adding gypboad to the existing stud walls, adding non-bearing walls and gypboard, slab exists, will meet minimum room size and head height when converted, etc.). It it's not a quick change, can't meet minimum size or height, and isn't conditioned it should not be counted as floor area.

Whatever my (or anyone else's) opinion is, it really boils down to what does the CBO in the jurisdiction determine it as.
 
Not a house person

But appears area or building area is not defined in IRC/CRC??
 
Thanks all for your responses. There is no definition of building area in CRC, and therefore defaults to the definition in the CBC. It is not clear if the mechanical crawl space would be included but based on your feedback your saying it would not count, but depends on the building department. So for now, we will not included it. Thanks again!
 
The IBC excludes basements from the total building area so why would you think a crawlspace would be counted

506.4 Single occupancy buildings with more than one story.

The total allowable building area of a single occupancy building with more than one story above grade plane shall be determined in accordance with this section. The actual aggregate building area at all stories in the building shall not exceed the total allowable building area.

Exception: A single basement need not be included in the total allowable building area, provided such basement does not exceed the area permitted for a building with no more than one story above grade plane.

506.5 Mixed occupancy area determination.

The total allowable building area for buildings containing mixed occupancies shall be determined in accordance with the applicable provisions of this section. A single basement need not be included in the total allowable building area, provided such basement does not exceed the area permitted for a building with no more than one story above grade plane.
 
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