Laser cut wood... The kit is made up from what we call the interior box, something all of our kits include. this makes for a very stable and strong base to build from. The exterior siding is applied to that. Kit includes all you see in the photos. Top shot is the O version, below the F/G scale model. O scale footprint is 2 3/4" wide by 3"deep, the F/G scale kit is 6 1/2" wide x 5 1/2" deep. The HO kit is 1 1/4" x 1 3/8"
