Here's one we built this year. Cost around $350-$400 unless you have some scrap materials. Has 2x2 frame covered with OSB walls, tilt in 3/16" glass windows (can be cut to size by local glass store), 2x4 floor joists with 3/4" plywood decking, and 29ga roof with 2x2 rafters and 1/4" decking. 8'...