I am a tenant in the UK. I live on the first floor (2nd floor in US scheme), there is no fire exit and the flat is big enough for a couple. The latch on my flat's door is the Ingersoll 'Classic' Nightlatch that is the first being described on the maker's website:
This lock can be double-locked from the outside: that is, once the bolt is already locked because the door shut, a clockwise key turn will push it a little bit more in a fashion that will not change anything, except remove the ability to open it from inside the flat -- even for someone with the key; since the only keyhole is on the outside.
That seems super dangerous to me. Imagine I leave in the morning, and unwittingly mechanically turn the key to double lock it. If there's a fire, what is my girlfriend left inside supposed to do? I can't comprehend the purpose of this, and how it is even safe to install such a lock on the single exit of a flat.
What is the purpose of this double lock mechanism? Is it safe and compliant with fire requirements in the UK? Is there a way for someone trapped inside to break free?
(The website presents this as a 'single dweller' option as opposed to a 'communal door' option that is identical but can't be double locked. Even for a single dweller, my questions remain, since any 'single dweller' would welcome guesses once in a while)
