Arch changed occupancy load after permit issuance

[Ben29]

We issued a permit for a 2-story new construction day care center last year. Arch permit drawings states Occupancy Load = 230 and Occupancy = E. So I designed the building for Risk Category 2. It has been about a year since we issued the permit.

Recently they sent me an updated 1st floor plan. I noticed that they had nine (9!) revisions since the permit set. I was unaware of most of these revisions. I asked them to send me a full set of the lastest drawings. At this point I noticed that they DOUBLED the occupancy load on their cover sheet to 460!!

I asked them why the occupancy doubled. I told them that this affects the structural design. Then they responded that the occupancy load was a typo, and that it is really 275. ^(*^(*&^%$^*

So the current design is Occupancy I-4 and Occupancy load = 275. Do I need to redesign this building for Risk Category 3? I feel the code is unclear about this (architect assured me that we are not Occupancy E, which would mandate Risk Category 3). I called the permit office and asked to speak to the building code official but I haven't heard back yet. We are now at a point where we are reviewing shop drawings. Upping the risk category would affect the wood shear wall design and parapet wind loading which in turn affects the wood roof truss design.

 

[phamENG]

IBC 2021 says it's Risk Category III. So the question is, what code are you using and what, exactly, does it say?

 

[Ben29]

This building was designed using IBC 2018. Group I-4 is not mentioned in IBC 2018.

Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to: •Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300. •Buildings and other structures containing Group E occupancies with an occupant load greater than 250. •Buildings and other structures containing educational occupancies for students above the 12th grade with an occupant load greater than 500. •Group I-2, Condition 1 occupancies with 50 or more care recipients. •Group I-2, Condition 2 occupancies not having emergency surgery or emergency treatment facilities. •Group I-3 occupancies. •Any other occupancy with an occupant load greater than 5,000.a •Power-generating stations, water treatment facilities for potable water, wastewater treatment facilities and other public utility facilities not included in Risk Category IV. •Buildings and other structures not included in Risk Category IV containing quantities of toxic or explosive materials that: Exceed maximum allowable quantities per control area as given in Table 307.1(1) or 307.1(2) or per outdoor control area in accordance with the International Fire Code; and Are sufficient to pose a threat to the public if released.

 

[phamENG]

Then it sounds like you fall under risk category II. I'd insist on a new set of drawings from the architect reflecting the 275. I'd also follow up with the Building Official to verify the code interpretation.

Also, make sure you let the architect know that the next code revision will change this and in future cases this will require a redesign.

 

[Ben29]

I spoke with the building official, this is what they had to say:

You should design this for Risk Category 3. Risk Category 3 includes uses where the occupants' ability to respond in the case of an emergency is limited, and that is certainly true in a daycare, probably more so than in a school. The 2018 edition does not directly list I-4, but it does indicate that the list included in Table 1604.5 is not exhaustive ("...including but not limited to...) The 2021 edition of the IBC code clarifies the issue by specifically including I-4.

 

[HDStructural]

That is a really frustrating situation you are in. Especially considering you are already reviewing shop drawings and will need to coordinate design changes during shop drawing review which isn't ideal. You should mark up your costs to the architect for this rework.

 

[Rabbit12]

So if the occupant load is 230 and an E is your design adequate as is? It was permitted for that correct?

 

[phamENG]

Bummer. Sounds like you need to explain to your client that if they want that higher occupancy capacity, it will come at a cost.

Your original design was code compliant. The occupancy size and use were below the clearly defined threshold stated in the code. Now, the building official has indicated that they want it designed for Risk Category 3. That change is being required by the building official, not by you, and it's coming about as a result of a change made by the architect. Therefore, I'd say you're more than within your rights to insist on additional services to produce a revision.