Here is a photo of a basement temple space I had years ago. I’ve always had very different priorities than is standard for this culture. Every place which I’ve lived I have always made sure to have space for a temple. To do this, I would just rent a place a bit more in the suburbs, or the slightly less trendy part of town, or have a roommate or 2. This allowed me to get a larger house or apartment for the same price as a smaller one. A spare bedroom for the temple was important. When I lived in a one bedroom apartment, I just sectioned off the livingroom so I could sleep there, and made the bedroom into my temple.
Basements, or attics can be very useful for this, or dens, or in a pinch a large walk in closet. While the temple can be in the same room as you sleep in, I have always heard that it is better to keep it separate, and I have found that it helps with the focus as well. Since one often chats on the phone, watches movies, or goes on the internet in the bedroom, that is most definitely not the mindframe or focus that is conducive for temple work. At one place, my bedroom and temple were in the same room, and that was fine too, but I prefer to give the invisibles their own room (or 2 lol). I find that having a specific and separate temple / ritual space, helps with focus for regular practice; whereas having it in the same space, there are to many distractions and thoughts on other things, and often there isn’t as much time set aside for the Great Work.