Mezzanine a story in a town house?

[Mr. Inspector]

They are building townhouses that ate 3 to 4 stories high. It could be a mezzanine ot a story depending how you look at it. In the definitions it looks like the IRC would call it a story which means you can't use the IRC for 4 stories. But the IBC (section 505) says it is not a story.

Not sure if I need to use the IRC or IBC. Also If they need to use 13D or 13R sprinklers.

Did not get the plans yet so I don't know the details. But they are asking me which kind of sprinklers they need.

What do you think? 13D or 13R? IRC or IBC?

 

[mtlogcabin]

2012 IRC Definition
MEZZANINE, LOFT. An intermediate level or levels between the floor and ceiling of any story with an aggregate floor area of not more than one-third of the area of the room or space in which the level or levels are located.

Wait for the floor plan to make a final decision
I tend to go to the max when there are no plans so IBC 13R until shown otherwise.

Code allows a 13D

 

[tmurray]

If they are 4 stories under the IRC and the scope of the IRC is limited to 3 stories, you must use the IBC. The fact that the IBC calls it a 3 storey building is irrelevant.

As for sprinklers, assuming each town house has their own independent system, 13D would be acceptable.

 

[PJC89]

Per the 2015 IRC:

R101.1 Title

These provisions shall be known as the Residential Code for One- and Two-family Dwellings of [NAME OF JURISDICTION], and shall be cited as such and will be referred to herein as "this code."

[RB] MEZZANINE. An intermediate level or levels between the floor and ceiling of any story

[RB] STORY. That portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above.

https://up.codes/viewer/general/int_residential_code_2015/chapter/1/scope-and-administration#1