Help With Vaulted Ceiling / Rafter Framing

[bassprokd]

Hello,

I am working on a home design for our new house. It is similar to the house we currently live in but we purchased a piece of property out of town. The current house has a vaulted ceiling over the master bedroom, which the wife wants to keep. The builder of our current home used roof trusses so it was not a big deal. However, I want to have a room in the attic for the kids to play, etc. I currently have a full size staircase leading to the attic as shown in the pics. There is currently only one interior load-bearing wall as shown in the plan view.
I am having trouble how to frame the vaulted ceiling. I know that I can use collar ties for the rafters but I don't want the vaulted ceiling over the master bath and closet. Also need help with the ceiling joists above the master bath and walk in closet (this area will not be utilized for play area). Anyone have any ideas how to build this without using trusses? Thanks in advance!
http://i72.photobucket.com/albums/i170/bassprokd/SecondStoryPlanView.jpg?t=1256004254

http://i72.photobucket.com/albums/i170/bassprokd/SectionView.jpg?t=1256004288

http://i72.photobucket.com/albums/i170/bassprokd/IsoView.jpg?t=1256004319

[JeffeVerde]

Run your right-side ceiling joists all the way to your left-side rafters, and then run your left-side ceiling joists to the right-side CJ's. I'm doing a project right now with the same design, except my left-side rafters act as ceiling joists for about half their span, creating a mini-vault just like you've got.

You'll need to size your raftes and the right-side CJ's to carry the additional load. If you're rafters are on the low end of the span for their size, you should be good. If you're already at maximum span, you'll probably need to bump them up a size. If the CJ's on the right side of that non-bearing wall run parallel to the rafters, you may not need to up-size the rafters, because you're essentially creating a truss. Run it by a structural engineer to be sure.