Was heißt »Treppenhaus« auf Englisch?

Das Substantiv Treppenhaus lässt sich wie folgt von Deutsch auf Englisch übersetzen:

Deutsch/Englische Beispielübersetzungen

Im Treppenhaus ist das Licht kaputt.: The light on the staircase is not working.; The light in the stairwell is not working.; The light in the stairwell isn't working.; The light on the staircase doesn't work.
Tom und Maria küssten sich im Treppenhaus.: Tom and Mary kissed in the stairwell.; Tom and Mary kissed in the staircase.
Gehen wir ins Treppenhaus, damit wir reden können!: Let's go in the stairwell so we can talk.; Let's go in the staircase so we can talk.
Der Fahrstuhl ist kaputt, und das Licht im Treppenhaus brennt nicht.: The lift is out of order, and the lights in the stairwell don't work.

How many steps does this staircase have?
A spiral staircase leads onto the gallery of the church.
So now he landed back in the same company, but this time not in the office chair, but rather upside down on the concrete staircase.
The toilet is behind the staircase.
The staircase to the loft doesn't have a handrail. It's not safe.
The staircase to the loft hasn't got a handrail. It's not safe.
The staircase balustrade was carved from red marble.
There's also a staircase if you're afraid of lifts.
There's also a staircase if you're scared of the lift.
Tom bounded up the staircase three steps at a time.