Is there a way you can scale an object in illustrator, while retaining the relative thickness of brush strokes?

I need to change the size of an object, but the brush strokes stay the same width (0.5) so I need to scale them all up individually which takes ages. I'd like to be able to scale the picture and the lines change width too, without having to rasterize it. It must stay vector, so rasterizing is not an option.Is there a way you can scale an object in illustrator, while retaining the relative thickness of brush strokes?
Firstly group your object, then go to the scale icon (tool bar) and double click on it. There is an option in the dialogue box to 'scale strokes and effects', select the box. You can also select a line and then, in select menu' select 'same stroke weight'. This will then pick up all the stroked lines of the same weight or width and so then you can input your new preferred stroke width just to those vector lines.