Hello JAE.
I was going to suggest some edits, but it may be better to share my thoughts and let you do any edits that you choose.
The point that I see is that you can design to any accepted standard, and you can exceed the requirements of any standard, but you must be very careful in how you describe the enhancements to the owner.
If the description leads the owner or occupants to draw erroneous conclusions you may find yourself talking to lawyers sometime in the future.
If you can make this point to the architect, then you may be able to work with him to find an acceptable description of the design.
@JAE:
I can only emphasize CYA CYA, CYA as you are in uncharted waters here…
To whatever form of wording you decide upon, I would add three dated signature blocks at the end, one for the Architect, one for his client, and one for your firm. No signatures, no work…
Once signed, include as part of the Structural submittal to the local jurisdiction in your structural Calculation package for public record.
Just remember that some clients… strike that… assholes will deny they ever were communicated with, putting the burden of proof on you as the professional.
CYA!
I’ll get off my soapbox now. 
JAE,
I am a Certified Engineering Technologist (CET) with a three year college diploma. I have been tasked on occasion to carry out structural calculations for safety purposes. I was not working in an absolutely professional environment, and I paid very close attention to my communications.
I attached my title CET to my documents and to my emails. This clearly shows what qualifications I have, and by implication, what qualifications I do not have.
I was very careful explaining my qualifications to co-workers, and I made sure this was passed on to customers. Typically, I submitted my stuff and they got to review it. I regarded one of my managers as dumb enough to claim I am a professional engineer, so I did my best to keep them out of the loop.
If you design a “hardened” shelter for a client, will end users be told it does not meet FEMA and/or ICC standards? If a sign is put up, will it stay up there? Do your clients understand your qualifications and the normally required standards? Do they have any tendencies to lie or BS?
“It was designed by a professional engineer!”
How much do you trust these people?
RevDesigner,
If you design a “hardened” shelter for a client, will end users be told it does not meet FEMA and/or ICC standards?
What the current owner will tell occupants, or what a future owner will tell occupants, is unknown to any engineer. That is the crux of my concern that, as I stated above, they will slap a “tornado shelter” sign on it and people will trust it wrongly.
If a sign is put up, will it stay up there?
Don’t know
Do your clients understand your qualifications and the normally required standards?
Well most all buildings in the US are designed by a PE, which I am (SE actually).
Do they have any tendencies to lie or BS?
Not usually.
How much do you trust these people?
It really isn’t that they aren’t trusworthy. It is that they probably don’t appreciate the difference between a vague hardened space and an ICC 500 shelter.