# Plumbing count for accessory occupancies



## PatrickGSR94 (Dec 18, 2017)

I couldn't find a thread on here addressing this already.  When you have a building of mostly one occupancy, with a small accessory occupancy (such as B office inside large S-1 warehouse), how are plumbing fixtures calculated?  Per the main occupancy applied to the whole building (just S-1 in this case)?  Or per each separate occupancy (S-1 areas/OL and B areas/OL)?

Does the IBC actually address this directly?  Couldn't find it in either IBC 508 or in IPC Ch. 4.


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## PatrickGSR94 (Dec 18, 2017)

Nevermind, I'm guessing 508.2.2 about each portion of the code applying to each individual area's occupancy would dictate calculating fixtures separately for each area.

Right?


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## Builder Bob (Dec 19, 2017)

Bingo.... however, a reasonable person might allow you to combine the calculations to keep from having one extra fixture = warehouse = 2.45 w.c. and business requires 1.35 

IF you don't combine - then warehouse has 3 w.c. and business has 2 w.c for a total of 5, if you combine and the travel distance is OK, then you might be able to get by with 4. 

i.e.  2.45 + 1.35 = 3.75 w.c 

This will be a matter of interpretation by the building official or the AHJ. I have seen people round up and round down on these calculations.


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## steveray (Dec 19, 2017)

Take the % or fraction of each by the fixture count table and add them together, I think the 2012 IBC clarified this for us...


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## PatrickGSR94 (Dec 19, 2017)

Builder Bob said:


> Bingo.... however, a reasonable person might allow you to combine the calculations to keep from having one extra fixture = warehouse = 2.45 w.c. and business requires 1.35
> 
> IF you don't combine - then warehouse has 3 w.c. and business has 2 w.c for a total of 5, if you combine and the travel distance is OK, then you might be able to get by with 4.
> 
> ...



Yeah but what I was asking about was for example, applying the 1/100 for WC's in S-1 occupancy to the entire building including the accessory B, or apply 1/100 only to the warehouse portion and 1/25 up to 50 for the B portion and so on.  And I believe the latter is the correct way.  And like @steveray said I add the fractional numbers together, and then round up to get the final count.


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## JPohling (Dec 19, 2017)

latter, combine and round up


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