If you select more than 1 wall and use stretch on the edge of the wall, rather than moving, it will stretch the other walls along with it.
Or use the marquee tool to stretch multiple elements at once.
A trick I sometimes use is to move the elements I want to stretch to the side at a fixed distance, operate the stretch there and move it all back, to avoid moving stuff on similar layers that I might not want to move.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
Windows 10 Pro
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