when is a window a wall

2009 IBC.

we have a client who wants to put a window in a wall, that has almost zero setback from a property line, common to the adjacent property. the building is a type V-A, with a Group A-3 Occupancy (gym).

we told him no, not permitted. but he's a very persistent man and not very good at being told 'no'. he thinks if he provides a two-hour rated fixed window, with 1/2" glazing, that because it exceeds the rating of the wall, it should be acceptable.

before i tell him no again, i thought i'd toss it out to the group here, in case there is a way to make this work.

another option could be glass block. if we used glass block, rated to match the wall, would it no longer be considered a wall opening, but part of the wall itself? nothing says the wall needs to be the same material for it's distance.

as always, appreciate any ideas and feedback.
Original Post
There are glazing products that are tested and pass wall standards for fire rating (in other words they are not tested per window fire rating standards).

If the glazing complies, it may be used in the opening since it will be treated as a "wall" not a window. Consult with one of the leading Fire Rated Glass manufacturers.

The Firelite product is not tested per ASTM E 119, which is required to be considered a "wall" and not an "opening." The critical item here is the heat barrier characteristic, which is not required in the requirements for opening protection.

However, TGP does have a product that meets the requirements for ASTM E 119 called Pyrostop. Note that the glazing and the framing need to be tested as part of a system, which TGP does have. I believe there are other manufacturers, although extremely limited, that have similar products.

If the glazing and framing system are tested in accordance with ASTM E 119, then there should not be a reason why the BO would need to approve it, since the IBC is very explicit in allowing glazing of this type in Section 715.2 (2009 IBC).
With the advent of the current crop of impact-resistant-fire-resistive ceramic glazing and fire-rated curtainwall [all very pricey!], I don't see why the building department would disallow the window wall concept as long as it is all fixed.

The programmatic question of glass in a gymnasium is a completely separate concern, though pending the size, 1/2-inch material would probably be fairly break-resistant...

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