How do i resize multiple objects at the same time in LayOut?

I need to resize the following objects at the same time (or just the walls at least), is there any way to do it? I use LayOut 2019

I am always amazed when I see someone produce this level of detail in Layout. I would only attempt that in Sketchup and then display it in Layout. Had you done that, scaling things would be a doddle. As it is…

But hats off to you for achieving so much with such clunky tools!