Obviously our situation is different, Im coming from a monastery, but for what its worth we practice both in the choir and in another space. We do all the major practicing in another space but once we are confident enough we normally do 1 or 2 runs in the choir before the mass because the acoustics can make it sound different.

We have access to a finished basement room, a choir vestry, and the loft itself. I prefer we practice in the loft. I think it's better to practice in the space where you typically sing.

We have a dedicated storage room for robes and music that could fit about 10 people, but we rehearse in the adjacent chapel.

I've had several various situations over the years.
The "choir room" was in the school building and doubled as the school music room for midweek rehearsals with the choir loft being the warm up space for Sundays. Though, the choir did have to go to the school building on Sunday morning to robe up so there was always that nice procession of blue robes up the sidewalk each Sunday morning.

There was a location where my office and the music library storage was under the organ in a transcept which was converted from a confessional. The choir rehearsed in the aspe, where they also sang from on Sunday.

The choir room/music office was in the basement, adjacent to the parish hall/school cafeteria and then a quick climb up the spiral staircase to the loft for Mass.

Currently, my office is in the historic building complex. There is a "choir room" adjacent to my office which is used primarily for the children's chorus rehearsal/music storage. The adult rehearsal room and storage space is in the main church behind the choir loft which was originally intended to be a pipe chamber for a pipe organ. This arrangement is rather nice in that we can rehearsal prior to Mass without disturbing those praying, though the choir room is not as sound proof as desired due to its intended use as pipe chamber and has a simple wall separating the back of the choir loft from it so some sound does pass through.

I have always had a choir room, or a space sufficient for Sunday warmups. Wonderful and helpful as it is to sing in the same space and acoustic in which one performs, a separate room seems very necessary to me for two reasons:

1) Vocal-health problems and other deficiencies in singing, particularly a failure to “support” and sing legato can be masked by a reverberant acoustic (and we thank God for that on Sunday morning). When the sound is swirling around, it can also difficult to pinpoint the reason for poor intonation and blend. Rehearsing in a drier room means there’s nowhere to hide, and the conductor can be more efficient in diagnosing and correcting problems.

2) The church (the sanctuary and nave) is not a place for any other business than prayer. I don’t know how anyone in the pews is supposed to devoutly prepare themselves for Mass while a choir is warming up and/or chatting in the church. And the music loses its lustre when the congregation have already heard the tricky bits picked apart and sung umpteen times.

We have a dedicated storage room for robes and music that could fit about 10 people, but we rehearse in the adjacent chapel.

Our schola used to rehearse in the janitor’s room/hall storage room/boiler room entrance. It was a tight fit when everyone showed up.

We have rehearsed in the church, the church basement, and the rectory basement at various times over the years. We currently use what you could consider a "sacristy-type" space off the sanctuary on the side opposite the sacristy. When the church was built in 1963, this is where the choir and organ were located for Mass; the space was open to the sanctuary (now closed off) and behind screens to the nave. This was altered in the 90s, where the choir was moved out into the front of the nave, and the former choir space became a "church library" which went mostly unused since covid. That arrangement has been discontinued and the books/shelves moved out, and we are now using this "library" space for rehearsals for both adult choir and handbells. The space is being renovated very soon to also accommodate school music classes, since they are without a permanent music room. We prefer rehearsing here to rehearsing in the church due to the acoustics - in the room we can hear each other well, but in church the acoustics are sooo dead.

We rehearse in the choir loft. It is not ideal, but this is where we store our books and honestly, it is inconvenient for people (older or not) to hike up and down our stairs. We also have a ton of books and music, you get the idea.

We get interrupted by the usual things and sometimes the unusual ones too.

There is certainly no place for warm-ups, but we are a rather simple bunch.