I think I know the answer to this, but it's not the answer I want, so I'll throw it out there:
I am working on an extensive remodel of a University dorm.The bottom of the existing rough wall opening is 42" AFF: with frame and trim, the glass starts at 45" AFF. Is it worth submitting and asking for an exception due to exisiting conditions? This condition, or full floor to header glazing exists in 100% of the regularly occupied spaces. Tons of glass. Bummer!