Q&A: how to divide up bedrooms

Sarah writes:

"First I do have to say how much I enjoy not only your comments but also the forum that you've created.  Thanks!

My question is about room sharing.  We have a 5 yr. old boy and 20 mo. old girl.  We've always had them share a room but soon we'll be moving into a new house (our first - yay!) with three bedrooms total.  But we'll also be having a new baby girl in two months.  So I was thinking that it might be best to keep the older two sharing a room for awhile and make the transition to a "girls' room" and a "boy's room" later.  But here's the thing, my 5 yr. old has all sorts of toys that are difficult/impossible for him to play with in peace (ie. Lincoln Logs, involved puzzles, etc.) except during nap times.  Would it be better to split up the older and younger siblings or am I asking for failure in the sleeping/napping department?  Ugh!  This seems like it should be so simple, more rooms = better/easier.  But I'm having such trouble figuring it out (haha!).  I think this may be one of those situations that would be greatly aided by someone with experience or at least a clearer brain..."

I love the comments, too, especially when what I say is wrong or incomplete and the commenters get to the real answer!

I think (and I know the comments are going to go a bunch of different ways) that I'd go with the big kid/baby split. Here's why:

The two older ones already know each other and are in practice with sharing a room. It's going to be something stable and solid once the baby comes and shakes things up for them.

I'm assuming you'll have more room in general in the new house, so your son can play with his many-pieced toys (the bane of my existence) in another room while your daughter naps. Also, in 8 months or so the pieces won't be as much of an issue because your daughter will be able to be more of a participant and less of a nuisance with the big-kid games.

More importantly, the baby could be a stellar sleeper or she could be one of those kids who needs a lot of help and tending for months and months. If  she is, the last thing you're going to need is to have the older children's sleep messed up because of her. Or, even worse, her sleep messed up because of them!

That's what I've got on this, but I only have two, and they share a room easily. Proposals and counter-proposals solicited for the comments section.