[Nealtw]

If you are making a room that needs insulation, you want 2x6 walls and 2x10 rafters
Put a king stud at each end or build a beam pocket in the side walls
The window want to be a min of 3" above the lower roof so you have room for pan flashing under the window and head flashing for the roof.

 

[Nealtw]

Nealtw -- thank you very much for the input here.

From your comments generally, I take it my use of the two LVLs as the full wall header means I can omit the top plate. I will use the king studs as you suggested.

With your suggestion of using 2X6 wall framing, the existing wall (below the existing rafters) is 2X4 construction. Can I add this short dormer wall with 2X6 framing when the wall it rests on is 2X4? For insulation purposes, I'd much prefer to use 2X6 framing, but didn't know if that was allowed.

With your suggestion of using 2X10 rafters for the dormer, my concern is achieving the correct ceiling height for the bathroom which will be installed under the dormer, as well as the correct roof slope.

This was my plan for framing the dormer rafters with 2X6 lumber, and I planned to use spray foam insulation to achieve R30:
View attachment 654627
Based on your suggestion of using 2X10, I would need to tie in the new dormer rafters to the existing rafters like this:
View attachment 654628
Is face nailing the new rafter to the side of the existing rafter allowed?

Thanks for your input here.

Is the 2x10 header there now?

 

[Nealtw]

No, the 2X10 header has not been installed yet. I've been trying to do all the prep work within the house before I take the roof off.

A header there will need support all the way to the foundation, maybe beams instead of joists under each side.
Is this what you have in mind, there may be better ways to do it.

 

[Nealtw]

There is an existing 2X6 wall which would be located directly under the proposed 2X10 headers, such that the headers would sit on the top plate of this wall, as well as attach to the uncut rafters on the sides of the dormer (which are also sistered). This 2X6 wall carries through to the concrete pad via a wall directly underneath it on the first floor.

So, since the 2X10 headers will have support, any idea if code allows joining of the new rafters to the existing ones using face nails only?

You have a concrete slab house? Unless the wall on a slab has a footing for bearing the slab is not a bearing point?
This would be a better way to go.