rucailo wrote:
Turn on the guides, place your cursor from where you want the guide line, (if you want to put the guide line 1 meter above) enter y 1 +

But if your wall isn't horizontal or vertical you can't use "X+/-" or "Y+/-" unless you want to play with rotated grids.

An easy way for any angled edge is to use the measure tool.
Hover over the edge to get the current (bold) guide line at that angle.
Now use measure tool and click first point anywhere on that edge.
Move away at right angles and type in the distance you want to measure (instead of clicking and actually measuring).
In the tracker click the little "Mark position" icon (crosshair icon) and a circular and perpendicular guide lines will appear.
Now you can add another giude line parallel to the edge (make sure the first guide line is still the current one) and the intersection of the circle and the perpendicular.

Just tried with version 12 and I get a circle guide andparallel guide line instead of a perpendicular one.
I'm sure it was perpendicular in previous versions.
Maybe I changed a work environment setting somewhere.
Either way you get what you want.

Barry.

Yes, I rather wanted a solution for a general case, not a horizontal or perpendicular one.
This one works rather well, so it will do for now. Thanks.