NEHRP Requirements?

[SteelPE]

I work mostly on the east coast of the US designing small building (mostly 3 stories and under). All of the project I do fall under the jurisdiction of the IBC. Every once in a while, months after a project is complete (in this instance 8 months), we get a request from the architect to provide the following:

"a certification stating that the building was constructed in accordance with the National Earthquake Hazards Reduction Program Recommended Provisions for the Development of Seismic Regulation for New Buildings” (NEHRP)."

The request usually comes from the owner, but at the request of a bank. I think the request is to just check off the box on a sheet a bean counter is looking at when approving a loan.

Now, I know very little about the NEHRP requirements. I remember the reference from seminars I have attended in the past, but that was years ago. I always thought the requirements were more of a west coast issue. We get similar requests every few years. Our typical response is generally that we designed the building to conform to the building code requirements.

I have always taken the stance that if a building was designed in accordance with IBC that it doesn't necessarily conform to the NEHRP requirements. Am I correct in this assumption?

 

[JAE]

I've not ever had that happen on our projects.
But the ASCE 7, on which I presume you based your design, is itself based on the NEHRP "Recommended Provisions".

So in your answer you could possibly say something like: "The design of the seismic resisting system of this building was based on the applicable local building code (IBC 201X) which in turn is based on the ASCE 7-XX, Minimum Design Loads for Buildings and Other Structures, which provides mandated seismic loads for this building. The seismic load criteria from ASCE 7-XX is based on the NEHRP Recommended Provisions."

Note that I used the term "design" and not "construction". If you weren't there to see very bolt and weld and other construction then I'd be very careful about certifying someone else's construction...your insurance carrier might be concerned about that.

 

[SteelPE]

JAE, you have never had that request from an owner before. I get the request every few years and it's always from a bank. We have always managed to tell them to buzz off but I just want to make sure I am helping my clients to the best of my ability.

Good point about the word constructed.

I was thinking maybe ASCE-7 would have us covered. I don't mind saying something in regards to conforming to IBC. I just don't want to go down that rabbit hole as you can be stumbled with certain words and terms. I like just providing reference to sealed drawings and signed CC affidavits as evidence that the building meets certain requirements.

 

[JAE]

Check the ASCE 7 commentary - they directly refer to NEHRP there and you might be able to allow them to check their little box if you show them that, essentially, ASCE = NEHRP.
There may be differences but one document is an adopted code and the other is "recommended" provisions.

 

[r13]

All US structural codes follow/use NEHRP recommendation in their seismic provisions. Yes, direct reference usually can be found in the commentary for the chapter that governs the seismic design. I would agree with you, this is just a check box type requirement.

 

[SteelPE]

There are quite a few references to NEHRP in the commentary of ASCE7-10 (the code used to design the building). However it does not appear as if ASCE-7 blindly follows the NEHRP requirements. I did find the following:

"Most of the commentary contained herin is devoted to noting and explaining the differences of major substance between ASCE 7 and NEHRP Recommended Provisions"

So it appears as if they use NEHRP as a basis for ASCE 7 but do no use it explicitly. I wonder if a statement that says something like:

The structure was designed in accordance with the __________ State Building Code/IBC2015. These building codes require seismic design to be in accordance with the provisions of ASCE 7-10. Seismic design recommendations within ASCE 7-10 are based upon the recommendations of NEHRP.

Although that seems like a very long way to get there. I suppose I can just wait and see what the client comes back with after our initial response of "We designed the building in accordance with _______ State Building Code".

 

[JAE]

I think that sentence is basically what I would use.