Shed Dormer-interior wall problem/confusion

[SCBHomes]

I'm relative new to Chief and stuck on how to fix a shed dormer issue.

 

I have a house with a 12/12 roof and I need a 13' wide shed dormer with a 3/12 roof on the second floor The bathroom is in the shed dormer.  My problem is that I cannot figure out how to connect the interior walls to the shed dormer walls.  If I drag the interior walls to connect, then I lose the exterior walls on the sides of the shed dormer and when I look at the overview, there are no "sides" on my dormer.  But if I don't drag my interior walls to connect, then inside the space I don't have walls here.

 

I'm guessing the answer is relatively simple, but I have searched all the forums and help topics and am getting frustrated with my inability to solve this.  I attached the plan and the imported CAD line drawing that will show you what the final layout of this space will be, so you can see what I am trying to do.

 

Thanks for the help.

Shed Dormer Help.plan

Shed Dormer CAD.plan

[Joe_Carrick]

Don't use a "Shed Dormer".  Build the Roof Plane manually and use regular walls for the 3 sides. 

 

Dormer walls are above the regular Roof, not below.