I am using Home Designer Architectural (have tried in both 2016 and 2018) to remove the ceiling above a room. I have designed new simple 4 wall rooms with a gable roof and I have also used an interior template. Once I change the roof to a gable and then remove the ceiling (single story room), the program adds an attic and the walls are invisible when viewed from the interior. However, if you look at the exterior, the walls are there. Can someone please explain why this is happening and how I can correct it? Thank you!