How often do you use the pre-built rooms?

I never use them. I think they're cute, but when I'm building a house, I have my own plan in mind, and these rooms simply don't fit...
I've made a couple for the gallery though, because I like decorating. But I haven't used them in my own builds either. :D

Never.

I have never used them.

I have used them, but three times in seven years tops. I save rooms I built myself to put down later, but it just isn't as easy to use the pre-built Maxis ones. They are like Maxis builds in the fact that I am always having to change things, sometimes serious things like walls and doors, so why not just do it from scratch anyway?

It is certainly possible to make a house with them, I've done it, but using them with no editing sounds like a challenge.

This being said, I know people that do use them and they do give players shortcuts to pack content, so I definitely want them to keep being made (and well). It just is not worth it to me to force them in.

I'm not much of a builder so I use them a lot. I've built whole houses out of them on numerous occasions. Some turn out kind of weird but others have been fine. I actually am not looking for perfection in either sims or houses in the game. Imperfection is more interesting to me so I embrace it.

I don't place them much but sometimes when I don't have inspiration to furnish a room I look at them. I mainly use them to find matching styles of furniture or a set. I really like that I just have to click on a particular piece of furniture in the room preview to grab it, no need to search in the BB catalogue.

Never used them, I have my own prebuilt rooms in my library of my gallery. But never the ones in build mode.

I used them for my first legacy when I built what I started calling “nightmare house.” I’m not a builder, so whenever the family had the cash and needed an additional room, I’d pop in a pre-built room. I decided I’d keep track of all the completed careers by adding in the career room once a sim unlocked it. The result was a maze of long hallways with random, but nice rooms; it earned that nightmare designation by being a pain to move through. The rooms on their own looked nice and saved me a lot of time furnishing things.

Now I just download whole builds off the gallery so I don’t need to use individual rooms. They’d be more useful to me for remodeling purposes if I could tell how big a room would be (and where the windows/doors are) before I tried to place it somewhere it won’t fit right. I’ve always preferred the style of the individual rooms over the maxis premade houses; maybe it’s just the exteriors I don’t care for.

I have used the Maxis-built rooms three times in all the time I've been playing the game.

I haven't used any since the first couple of days I after I got the game. Playing around with them at that time showed me that they're a waste of my time. I invariably changed so much about them to better suit my tastes that I was better off designing my own rooms in the first place. And that was that.