bg8551

I have Home Designer Architectural 2014 software. I want to add dimensions between furniture pieces that I have placed in a room. I cannot seem to find how to get the dimensions to not disappear every time I try to draw a dimension line from one piece of furniture to another or between furniture and a wall. Appreciate your help.

I am trying to draw a cathedral ceiling with a flat center. According to the tutorial I need to select the ceiling plane which I cannot find. The tutorial states that it is under the roof tab, but I do not see it there.