I am being asked to add language for Delegated Design of all exterior HM doors, including sealed calculations. Project is in Vegas. I asked what they want designed (these are standard exterior insulated exit doors) and didn’t receive much of a response. Does anyone routinely require delegated design for standard HM doors? If so, i would love to see your language and what you ask for. TIA
I like to do delegated design for door hardware, and to do that, our door schedule identifies all the parameters and functions and specific features of a door, and the door contractor selects the specific door and hardware accordingly. Is that what they are looking for?
no, they want the door itself to be delegated design with sealed engineer calculations.
We have never specified it that way. Sounds a bit overboard.
Robin,
I feel your pain, but this (hollow metal) is a new one to me. Generally, whenever I encounter a design professional (or developer or Owner) who doesn’t know what they want, and thinks they can avoid getting their hands dirty by merely making a decision or committing to something, they’ll invariably assume the “just write a performance spec” stance. Then the fun begins: I’ll promptly concede and (somewhat joyfully) ask them for all the performance criteria they wish their [insert product/assembly here] to meet. I’ll explain to them that the delegated design entity can’t design “X” until they are given all the necessary performance criteria the Architect/ Owner/developer wishes the product/assembly to comply with. In the great majority of instances, they come away with the realization they don’t really know what a performance spec really is, or how to respond to the simple request for the design criteria, and end up folding like a house of cards. Ultimately I end up writing a more conventional spec section that more than adequately gets the job done.
Hi Robin.
David makes some excellent points.
I suspect that the delegated design is related to wind loads, but it could also be related to thermal performance, but thermal performance can be documented by a test report.
Whatever it might be, the IBC does not require any design calculations for exterior hollow metal doors.
Specifying delegated design for an exterior hollow metal door can be done, but getting a door manufacturer to submit calculations seal by a licensed engineer may be impossible. I am involved with the Steel Door Institute Technical Committee, and I suspect the SDI manufacturing members would laugh at the thought and simply not price the project.
Robin, is it possible that they once did a project with custom HM exterior doors and frames that had to meet some special criteria such as oversized openings, “hidden doors” in the exterior cladding system (we used to clad HM doors with stone veneer to blend with the facade), special acoustic or security or thermal needs, etc. and now they think that delegated design is the norm since they did it before?
Requiring calculations only begins to almost make sense if there are special code requirements for hurricane or blast resistance that need to be met.
If wind load is the issue, I suggest including requirement for Miami-Dade NOA or Florida Product Approval for HVHZ for HM doors; that way you will get the engineering as it has aleady been completed and filed and avoid the expense of custom engineering for the project.
Although structural performance for the door and frame is important, the details (and engineering) for anchoring the frame to the building structure are equally important. I have begun to include a requirement for an installer certification indicating that the installation complies with the details.
If they are asking for delegated design, they have to advise what the performance characteristics they want are. Once you have that (assuming they make sense), you can then see if standard products meet that performance. If a manufactured and tested product is available, The only difference I can see for delegated design would be a certified report for that particular project by a particular engineer. Yet, you can get certified test reports for the product as opposed to the project. These are both effectively the same thing, IMO. Exception: some sort of highly unusual situation that requires a custom design.
It doesn’t seem like they know exactly what they’re asking for.
I found that many persons only think of specs as Proprietary (that they understand) and “Performance” (that means all other forms of specification) seldom do they actually know what “performance specifying” is.