I use home designer- pro 2019. I am able to change the dimensions on 3 sides which are straight but it is the arc on one side that is causing issues. I posted this on the home designer forum as well. I tried some other steps based on the suggestions there but still unsuccessful. If I may copy and paste my post here to see if you or anyone else can help me with this.
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I tried by turning off the snaps and after selecting the dimension with mouse click (arc line), filled 20' in the box. Same issue remains for the arc
Then I filled the 20' setback under preferences> edit behavior> concentric > jump, thinking that I would not have to change anything on the arc and will rather change the straight edges on the sides by filling out the dimension boxes. This time too as the change occurred on sides the setback got distorted at the arc
When I first chose concentric>jump for 20', it comes out fine all sides including the arc. It is when I change the dimensions (by filling the box) either on the arc or any sides, that the arc setback gets distorted.