This is a really interesting question, and I’d love to hear your thoughts on it…

Some new fire doors were ordered and manufactured with 5-inch x 20-inch vision lights located with the bottom of the light about about 46 inches from the bottom of the door.  The AHJ pointed out that if a door has a vision light or sidelight, the bottom of at least one light has to be located no more than 43 inches above the floor.

The doors are 90-minute-rated, and are on site.  What’s the best way to solve the problem?  There are several issues…the requirements for modifying fire doors in the field, the limitations on the amount of glazing allowed in a 90-minute door, along with the required light location and potential light/lock conflicts.  If the door manufacturer’s listings would allow more than 100 square inches of glazing (possibly with fire-resistance-rated glazing), and if the listing lab would grant permission to modify the doors in the field, perhaps a longer light or a second light below the first would work.

The end user raised an interesting option.  There is an exception in the accessibility standards for lights that are located above 66 inches AFF.  Since those lights are for light transmission and not for viewing, having a light at the top of the door is acceptable.  So what if the vision lights on the project in question had frosted glass – which would permit light transmission but not viewing?  Although technically this is not addressed in the accessibility standards, would this meet the intent?

The answer may depend on what type of facility the doors are located in.  If it’s a business occupancy, for example, changing the vision light to a light that’s for light transmission and not for viewing might be approved by the AHJ.  But in a health care occupancy, some doors are required to have vision panels.  Here’s an example from NFPA 101-2012:  “* Vision panels consisting of fire-rated glazing in approved frames shall be provided in each cross-corridor swinging door and at each cross-corridor horizontal-sliding door in a smoke barrier.”  If the vision panel is required in the location where these doors are installed, I don’t think frosted glass would be an option.


  • Is frosted glass a potential solution if the vision light is not required by code? 
  • Have you run into this problem before (lights that are too high)? 
  • If you supply or manufacture doors, do you have a process to check for the proper light location before fabricating the doors?

Note: The photo included in this post is just for reference – it is not a photo of the actual doors in question.  And yes – it is a RHR/RHR double-egress pair which is a whole separate issue, and also – the panic hardware has dogging because it’s not fire exit hardware.  I just used a photo that showed too-high lights.

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