Creating templates with Free Web based SketchUp

Hello all , i am trying to use the web based SketchUp (free) to design a BBQ and grill area. I have alredt planned this old school style with pencil and graph paper. I now want to put together a full design plan using the bricks / breeze blocks , mantels and all related building components that I have decided to use.

Is it possible to make templates of the materials (such as the Breeze blocks , with all relevant dimensions, and the use these templates to build the design on SketchIUp ? I am ideally trying to work out the best layout and ultimately the number of bricks, breeze blocks etc that would be required to build the BBQ within the planned grill area.

Any advise would be greatlt appreciated
Thanks
Malcolm