Trying to make room bigger

I am trying to make the bigger rectangle - bigger… i did it to the wrong dimensions. I have tried to separate it from the smaller box, by adding lines so that i only select the 3 main walls… but i cannot seem to do it, when i use the scale tool it’s still dragging the inner wall part…

Use Move tool

Learn the basics of SketchUp

Omg wow! thank you!

Have a look at this too - comes with audio. It’s in the package Mihai.s linked to.