This can be done currently the following way:
1. Turn on Snap Guides and set it to the "Distance" option.
2. In the "Set Snap Point Values" Dialog, set the desired value for the distance (e.g. 100 mm if you want to place a Window/Door from the Wall corner).
3. Make sure you also have the "Between Intersection Points" option active, so Snap Point will be measured from the intersection point of your connecting Wall.
4. Hover your cursor on the Wall edge near the corner and Snap Points will appear at every 100 mm from the corner. Click the first to place your Door/Window.
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