Q&A: older kids sharing a room

Amy writes:

"I'm expecting baby #3 and will have some space issues when this onearrives. We live in a 3 bedroom house, but one of the bedrooms is downstairs (not the Master) and neither of my chlidren (currently 6.5 and 4.5) want to sleep down there alone. So they share the other upstairs bedroom. They are a boy and girl, but at this age they don't seem to care about sharing the room. We have several options when the new baby arrives for bedroom sharing, but I'm leaning towards making the downstairs bedroom a "sleeping porch" and turning the upstairs bedroom into a big playroom/family room. The idea behind this is that the "sleeping porch" would only be for sleeping--no child can enter the room until it's time to sleep, while the upstairs playroom will serve as the space for all toys, a kids TV, all books, etc.

Now to the question... I'm an only child and therefore totally ignorant about children's needs for personal space. I realize that at some point my son (the oldest) will want his own room, as will my daughter, but at what age will that occur? Do you think the sharing of a "sleeping porch" will work until one of the older children is comfortable having the downstairs bedroom all to themselves at which point the upstairs room can be reconverted to a bedroom for the other two?

I'm also open to other suggestions about bedroom sharing between different-sex children."

I kind of dig the sleeping porch idea. It's very bunk-beds-at-Grandma's-cabin-with-your-cousins-in-the-summer. The only concern I can think of about it is whether all three kids will be able to fall asleep together in the same room, or if it'll end up being an all-night gigglefest. Since your older two already share a room successfully it's probably not going to be an issue, since they'll set the tone for the baby.

My kids are still little, and my brother and I stopped sharing a bedroom when I was maybe 8 (I can't remember, so it must not have been an issue, although I do remember being really excited to choose the paint color for my new room), so I don't have any firsthand knowledge of when kids of opposite sexes want to stop sharing a room. My hunch is that they'll start wanting their own space as preteens, right about the same time they'll be excited about having a bedroom on a different floor from everyone else.

I think as long as your kids know that they can tell you if they want to switch, you won't have to worry about it until it happens. It might not be the older kid switching out for a single room, either. It's possible that the two older ones will start annoying each other, but the oldest one will still be fine sharing with the youngest one (whether it's a boy or girl), so the middle one will move out. It seems like this is the kind of thing that will depend so much on individual personalities that there's no way to know how it will go until the baby is here and interacting with the other two.

Any readers out there who have gone through this situation with siblings of opposite sexes already? How did room-sharing go? At what age did the kids want to stop sharing? Any tips to make this easier for Amy?