Occupancy Category

[SteelPE]

I have another Occupancy Category Question.

I am currently working on a building that houses a air ambulance operation. You know the people. they transport patients by air from one hospital to another or fly to the site of an accident to transport someone to the hospital. I have classified this type of structure as a Occupancy Category IV building as this type of structure is used to house the aircraft used for this recovery process. I think this is a reasonable assumption especially since Occupancy Category IV building are to include "Fire, rescue, ambulance and police stations and emergency vehicle garages."

Now, every single sub contract engineering contractor who submits shop drawings list the occupancy category as II and it is driving me crazy. I was very clear with the contractor as to the requirements of the building at the onset of the design (I am working for an architect but the owner has already hired a contractor to work with the design team). Am I not interpreting the requirements properly?

 

[SLTA]

I agree with you - it looks like Cat IV. Reject all the shop drawings, with copies of your initial correspondence if in writing. You're the EOR, after all.

Please remember: we're not all guys!

 

[SteelPE]

SLTA, that's what I have been doing but it's making me paranoid that I made the wrong interpretation.

 

[TehMightyEngineer]

Under the 2015 IBC it lists under Risk Catagory IV:

[ul]
[li]Aviation control towers, air traffic control centers and emergency aircraft hangers.[/li]
[/ul]

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[SteelPE]

I don't have the 2015 IBC and the project falls under the 2009 IBC, but that does give some justification to my decision.

 

[SLTA]

2009 IBC is what I checked, and says the same thing.

Please remember: we're not all guys!

 

[DaveAtkins]

A lower occupancy category leads to a design which is less conservative, which means a design with a lower factor of safety against failure. I would say a building where an emergency helicopter is stored is one of those buildings which you don't want to fail. I agree it should be Occupancy Category IV.

DaveAtkins

 

[wannabeSE]

I agree with the others. Plus, the contractor bid on category IV. Even if II met the minimum code requirements, how much credit (money back) do you think the contractor would give the owner.