OK, sorry for my unpatience. Thank you for the recommended plugin, but first I try to follow the basic tutorial. When I am ready with it, I'll install this plugin. I suppose, the training video is made for the basic Scetchup vithout plugins.

Where is my submitted reply? I don't know, but I repeat it.
Dave, your instruction works well on Push/pull. But when I try it with Offset, it doesn't works at all. I select the first offset-area, change to Offset tool and double-click on the other rectangel (window). I get a huge rectangel around the first rectangel.

Thank you for quick answer, I will try it tomorrow.

Hello, I am very new here and in SketchUp. I follow the tutorial http://www.sketchup.com/intl/en/training/videos/new_to_gsu.html# and I get problem in the 7th minute. Please, tell me,how to use the Push/pull and Offset tools in this way, getting the same size. (Maybe she says something I don't understand, because spoken English is difficult for me.)