# Building classifications? III, IV, V



## Bob Badger (Apr 19, 2009)

01Admin said:


> Is there a occupancy limitation in either class III, IV, V building types. My question is in regards to the use of Romex in other then dwelling units as allowed in NEC 334.10. Thanks


In the back of the code book the construction types are defined. The number of people is not part of it.


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## 01Admin (Jan 19, 2010)

I looked at this in Annex E but wanted to confirm because the annex is for informational purposes only and not always accurate to our region. I have from others in the industry that there is a 100 person occupancy limit regarding the use of Romex?

Thoughts?


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## raider1 (Jan 22, 2007)

01Admin said:


> I looked at this in Annex E but wanted to confirm because the annex is for informational purposes only and not always accurate to our region. I have from others in the industry that there is a 100 person occupancy limit regarding the use of Romex?
> 
> Thoughts?


There is not "100 person occupancy limit" with regards to when NM cable is permitted to be used.

Building construction type III, IV or V are buildings that permit the use of combustible construction. There are area limits to how big a building can be built or how high a building can be built using types III, IV or V construction.

So really the limit to the use of NM cable in regards to building construction type has more to do with the allowable area of the building than the actual occupant load.

Also keep in mind that NM cable can't be used in assembly occupancies that use fire rated construction. (See 518.4(A))

Hope this helps

Chris


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## codeone (Sep 15, 2008)

01Admin said:


> Is there a occupancy limitation in either class III, IV, V building types. My question is in regards to the use of Romex in other then dwelling units as allowed in NEC 334.10. Thanks


An occupancy limitation is not necessarily a person count. An example of an occupancy where NM is not allowed is at 334.12(4) and (5). The building code regulates the type of construction by an occupancy use.


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## miller_elex (Jan 25, 2008)

I've got an illustrated guide to the IBC that helps with knowing all the types, etc. 

If Romex is verboten, next best would be AC Cable and device boxes with internal clamps. It has to beat pulling romex into any raceway just because of the labor.

As of 2008, isn't Romex allowed in even a type I as long as it is in a raceway?


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## raider1 (Jan 22, 2007)

miller_elex said:


> I've got an illustrated guide to the IBC that helps with knowing all the types, etc.
> 
> If Romex is verboten, next best would be AC Cable and device boxes with internal clamps. It has to beat pulling romex into any raceway just because of the labor.
> 
> As of 2008, isn't Romex allowed in even a type I as long as it is in a raceway?


Yes, there is a new exception to 334.12(A)(1) that permits NM cable to be installed in a Type I or II building where installed in a raceway that is permitted in those type of buildings.

Chris


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