ExH lives in a ground floor flat. It's a block of flats and there is only one door. His front door leading onto a corridor or other residents front doors.
Every window in the house is covered in bars. Not unlockable, but attached the the window frame with screws, for security reasons I presume.
Only if there was a fire and the main (only) exit was blocked there is no quick escape bar getting a screwdriver out to remove the bars. Totally impractical of course.
Since the Grenfell Tower accident and also the flat fire in Manchester today I can't help worrying about fire and what would happen if there was one when my kids stay over.
Can he ask the landlord to remove them?
Google photo for similar refence