How do I create shed dormer window cut-outs in main roof

[Lynx_Design]

I am working on an add-on garage project. The preexisting house it will attach to is a salt box design, see images below.

 

I have created the main roof and shed dormer but have no idea how to go about creating the cut-out portions of the main roof below the dormer windows, see image 1. I am new to Chief Architect (using X12) but I can not seem to find a way of creating this detail in the model after  looking through the help documentation or reference manual, this is a rather uncommon roof/dormer detail in my experience. Unfortunately the breezeway roof that will tie the garage into the house intersects with the main roof close to these dormer window cutouts so I need to model them to check my tie-in roof location and pitch works. I have attached the current chief file also.

 

If any one has an idea how to approach this please feel free to respond.

Thanks,

 

Chris

 

Garage Addition.plan

[GeneDavis]

Break the roof edge each side of window, drag edge down. 
 

In the no-roof rectangular hole you've created now needs a lower-pitched plane in its place.  Manually draw it and adjust pitch to suit.

[Lynx_Design]

Thanks Gene,

I will try your recommendation.