Install them after final inspection and assume the liability.
Garage attic ladder fire code.
The easiest way to do this is to replace the access door itself to be fire rated and simply retrofit the ladder to it.
A literal host of code requirements come to mind.
But when you put something else in the opening it must be equivalent to 1 2 drywall which has roughly a 20 minute fire resistance.
It may be easier to install a regular non fire rated attic access in the garage then make sure that the walls of the garage that abut the living area are 1 2 or 5 8 whichever is code in your area from foundation to roof line.
The international residential code irc is similar.
Combustion air also called make up air can also be provided by a vent through the wall.
Here are my concerns with adding 5 8 type x drywall to the pull down attic ladder in the ceiling of the garage which is the required modified firewall.
We do not allow door stops on the garage door.
The only time it is required is if the garage attic is separated from the house attic.
Contrary to popular belief acceptance and use the attic access is for fire personnel only and is not meant for even incidental storage.
No access from attic over garage to attic over living area.
Shown below is an example of what not to do a grille cut into pull down attic ladder and an example of the right way to add a vent a register in the ceiling of garage that connects directly to a roof vent via a metal duct viewed from the attic.
Permanently installed pull down attic access ladders code violation.
Most homes have a 1 2 drywall panel installed in the attic access opening which is fine.
But codes can vary from county to county and this might be one of those.
The pull down attic ladder is not self closing.
Until it is code that all garage ceilings have 5 8ths sheetrock on them and as long as ladders receptacles holes from brackets where garage door tracks are mounted etc penetrate the separation leading to attic areas common with the residential attic i will continue to recommend that clients install separations between the garage attic.