A quick dormer/roof

[JasonL]

Hi, I'm really getting into this - hmm, I didn't get much sleep last night looking at the different possibilities!

I've managed to get a good approximation of the building already. My question is - is it possible to extend the roof below the window. The program has the roof configuration shown on the left and right hand dormer window, and I've done an example of what I'm after in a graphics program on the middle window. The wall of the house is on the same vertical plane from the ground to the top of the window gable.

Is this difficult to do?