Extending Wall

I am working on a design of a building, particularly the vestibule. The vestibule roof will be a gable roof; however, how can I extend the wall that the doors are located to go clear up to meet with the roof? It will also have returns on it.

I have attached a picture of what I am talking about.

Thanks.

If I understand you correctly, you want a gable wall above the front door. I typically do this by going to the attic floor and draw in an exterior wall. A box will appear asking you if you know what you are doing, close it, and press F12 or the rebuild walls button, and it should fill the space below the gable roof. You can also create this in elevation view by selecting the wall that the door is in, breaking the top of the poline, and dragging it up to fill the gable. This works best if angle snaps are off, but the first method I explained automatically fills the space and is 'cleaner.'