Acesalad

I am trying to recreate a house to show how it would look updated. It is a Cape with a shed dormer. I followed the knowledge base article on creating a shed dormer, but as you can see in the picture, the back wall of the shed dormer is a continuation of the first floor back wall and in my design the walls are separate. I cannot figure out how to make these the same wall. I am using Home Designer Pro 2019.

Thank you solver. This seemed to work although I got the "This operation modifies one or more automatically generated walls. The walls(s) will be retained and will not regenerate automatically. Would you like to continue with the operation?" message. I did not think to go up to the Attic level and stretch the walls. I also took your advice on my signature. Thanks again!

I was doing the Basic Roof training webinar and in the part where he designs the Shed style dormer, I followed the instructors directions but I still get a gap in the walls. Attached is a picture of my screen. Does anyone know how to eliminate these gaps?