Other than whatever might be hidden inside what's currently the back wall of the larger closet, I'm guessing the biggest issue would be the flooring (or lack of it) under that wall. That will take some patching.

Have you thought about two smaller reach-in closets for the larger bedroom, instead of the corner closet, maybe flanking that bottom window, and connected by a window seat w/storage? You might actually end up with more usable closet space.

You will have to patch the ceiling and the floor of the smaller room.

I don’t quite understand why the flooring would be an issue if you are keeping the closet still as a closet in the smaller room. If you want to take off the wall between the closets, you’ll have to figure out door options.

I think the new red closet seems awkward. Maybe put closet in opposite corner (top left) or I like the idea above about flanking the window.

IMO the corner closet makes no sense as the closets are is how they are in most homes and IMO the corner one also now creates issues with room layout. IMO we need meaurements too .

@J P as I read the post, the former large room closet will be floor space, not closet, in the new arrangement. The OP is trying to make the floor space more equal between the 2 children's bedrooms.

I don’t think it would be too hard and even if the floor doesn’t match perfectly, with a closet door and stuff on the closet floor, it’s not as important as if you were removing a closet.

I would rethink where to put a new closet in the bigger room. Would it fit to have a reach-in closet in along the wall in front of the existing closets?

Overall I think your idea is a really good one.

Thank you all for your suggestions. I agree there are potentially many better solutions for the closet in the larger room and I appreciate the ideas.

I was actually more focused on understanding if anyone had seen this idea of swapping which room the closet would open into. I was trying to see if anyone had thoughts on whether we'd likely run into electrical or plumbing in a scenario like this where bedrooms share a wall. The floor and ceiling in the closet are consistent with the bedroom so I think the only issue might be the floor where the wall in the smaller bedroom would need to be opened up. We would probably continue to use the space as a "closet" although that might just mean that we put some of the existing furniture (bookshelves, bureau, etc.) in it which would free up more floor space in the room.

When we thought of the idea, we figured we weren't the first ones to think of it!

Thank you all!