A 4 story rope ladder would be... interesting to clamber down. Shorter rope ladders (usually steel wire these days) are pretty hard to go up unless you practice on them and they are flat miserable to go down unless you're a normal, active 8 year old...

If you have two sets of stairs accessible from your hallway, I don't think I'd bother.

If you still want to be able to egress from the window, put together a rappel system and learn to use it. Either a conventional system like cavers might use or go up one notch and get specialty rope that is designed to (briefly!) withstand exposure to higher temperatures. Think thru your anchorage options - it's not difficult in a building, but it might cause you to add a tool or two to the kit (a halligan would be nice...)

I like the building stairs, myself.

My 2 cents.

Tom