Couple questions in regard to occupant load for plumbing fixtures

[TheCyclist]

My understanding is that occupancy classification in primarily used to determine necessary separation ratings while occupant loads are used for egress sizing and plumbing counts. The two aren't necessarily tied together, but you'd never have an assembly space, but then categorize it as storage when determining the occupant load.

Correct me if I'm wrong, but if I have a conference room within a business space and the conference room is an accessory use space, it should still be counted as an assembly space when determining the occupant load. However, would it be possible/reasonable to categorize it as business when determining the water closet count if the only intended user of the conference room are the employees of the adjacent business space? This may just depend on our local jurisdictions.

I'm also wondering if it's okay to share occupancy loads amongst water closets. For instance, if I have a large warehouse space where part will be used for manufacturing and another part will be storage, if I categorize the entire space as the higher occupant load and still fall under the more strict water closet count b/w storage & factory/industrial, could I say that a given amount of water closets would be adequate to serve both spaces even though their uses are different?

 

[Ed Cooke]

My understanding is that occupancy classification in primarily used to determine necessary separation ratings while occupant loads are used for egress sizing and plumbing counts. The two aren't necessarily tied together, but you'd never have an assembly space, but then categorize it as storage when determining the occupant load.

Correct me if I'm wrong, but if I have a conference room within a business space and the conference room is an accessory use space, it should still be counted as an assembly space when determining the occupant load. However, would it be possible/reasonable to categorize it as business when determining the water closet count if the only intended user of the conference room are the employees of the adjacent business space? This may just depend on our local jurisdictions.

I'm also wondering if it's okay to share occupancy loads amongst water closets. For instance, if I have a large warehouse space where part will be used for manufacturing and another part will be storage, if I categorize the entire space as the higher occupant load and still fall under the more strict water closet count b/w storage & factory/industrial, could I say that a given amount of water closets would be adequate to serve both spaces even though their uses are different?

When using Iapmo as the code, I have the designers specifically provide the occupant load for each space, even if the area is a mixed, A, B, F, S, or whatever. That notes how many folks are really possible in that location, I then apply Table "A", since they rarely do it, and check against Table 422.1. I think this is the most reasonable as each area is accounted for by the design professional.

 

[Sifu]

Is it reasonable? Yes, but it would require some critical thought and analysis....which can lead to inconsistent application of the code. As a non-simultaneous use (like the guy sitting in his cubical (ME) who gets up and goes into the adjacent conference room and nobody replaces me at my hole) it is reasonable. But for a public access conference room, where there could be multiple outside attendees, it may not be. An alternate request may be the way to handle it. I like those to spell out the reason why it is requested and how it meets the intent or is equivalent in safety. I then attach that to the plan to justify the decision as a specific condition and case.

There is a code change proposal to address conference room occupant load for the 2024 code because this is a common issue and question. E8-21, it was disapproved 14-0. It cuts the occupant load to 30 gross. I think it is a good idea but needs more work (committee did too), public comment provided better reasoning by capping the areas that can be considered at 30(net) to 750ft², then reverting back to 15 net. The PC seemed to consider the "public" access rooms I refer to. I support the code change with the PC FWIW. I am not sure if it made it through Pittsburgh or not...can't get on the ICC website.

As for the second question, I think yes. As long as the fixtures are within travel distances and access is available to everyone, the total number is the important part. Think of an office building with separate tenants. A common set of bathrooms is used by all the different uses in the building/floor. Not sure why it would be any different for your situation.

 

[Sifu]

BTW Welcome to the forum, no better place to collaborate and find answers and opinions. I spent about a 1/3 my life in middle TN in and around Nashville. Good to see a user from that neck of the woods.

 

[mschirmer]

Side rant....I do not understand the plumbing code for commercial buildings. Isn't the idea to conserve water and the environment? 3 or 4 toilets is enough for a floor. I've had buildings where AHJ stuck strict the code and it required us to put toilets inside the space because buildings were built with 8 toilets in mind.....PER SEX. It's ridiculous. Sorry. just venting.

 

[Tim Mailloux]

Side rant....I do not understand the plumbing code for commercial buildings. Isn't the idea to conserve water and the environment? 3 or 4 toilets is enough for a floor. I've had buildings where AHJ stuck strict the code and it required us to put toilets inside the space because buildings were built with 8 toilets in mind.....PER SEX. It's ridiculous. Sorry. just venting.

its the amount of people using the fixtures, not the actual number of fixtures that will impact water use. 100 people sharing 4 fixtures will use just as much water as those same 100 people sharing 8 fixture. More fixtures inst going to make people need to use the rest room anymore.

 

[mschirmer]

Technically no. Water is required in each toilet. Cleaning done on a routine basis creates water waste. Empty floors still get cleaned and water wasted. Most people don't use water fountains but 1 per 100 is still required. Most building owners don't want the ugly water fountain either, at least where I live.

 

[Ed Cooke]

Technically no. Water is required in each toilet. Cleaning done on a routine basis creates water waste. Empty floors still get cleaned and water wasted. Most people don't use water fountains but 1 per 100 is still required. Most building owners don't want the ugly water fountain either, at least where I live.

FYI, in California, the water use barely is allowed. In non-res you get .2 gal for a lav, 1.28 gal for a w.c., .125 gal for a urinal. Since most are auto flush, most people walk away without even flushing, assuming the fixture will take care of it! So wasted water??? Hardly!!!

 

[TheCyclist]

BTW Welcome to the forum, no better place to collaborate and find answers and opinions. I spent about a 1/3 my life in middle TN in and around Nashville. Good to see a user from that neck of the woods.

Thank you, I enjoy it here. I hope to find these forums a useful resource going forward. I've worked on plenty of residential architecture, and I'm just getting my toes wet with commercial architecture.