Hello
I've been having issues lately with displaying the correct measurements of the walls. As seen below the furthest left wall states 15'6" but the other walls to the right state 15'1". Prior to adding the walls to the floor plan I have set them all to 15'6" and after adding them they change measurements.
I've had this difficulty with all of my floor plans and found that if I adjust the wall to 15'11" and re-add to structure the desired measurement is achieved. That isn't working for me this time. 
