How do I change the height of the windows. In 3D they are all the same

How do I design a stair that leads to the floor below?

On my second floor I want to place a railing along the open to below area. The bannister doesn’t help as it becomes a closed wall in 3D. Using a fence also doesn’t help as they are not 3D. I …

Do you have full glass doors, other than the double hung doors, as I only want to place a single glass door

In one of my three floors all of a sudden all the interior walls are gone (both in 2D and 3D). The doors are still there. 18656498- 1st-floor