From version 12, avoid creating multiple elevations every time you double-click on the same placement zone more than once.
There is a check box in Preferences: Select existing elevation on double-click.
By default, Design does not create a new elevation when you double-click on the same placement zone more than once.
If you prefer working with duplication of elevations, choose from the following options:
In the ROOM LAYOUT ribbon, in the Views group, click the Add Elevation icon OR deselect the Select existing elevation on double-click check box in the Walls/Construction Lines pane of the Preferences dialog box. See capture below:
Double-click on the same placement zone more than once without duplicating elevations
