our brooder, built by my husband : sides, bottom and back were pre-cut and pre-sanded plywood, bought at home depot. Sides = 24" x 24". Bottom panel and back panel = 24" x 48". To keep it light we used 3/8" for the bottom, and 11/32 for the sides and back. In keeping it light, we also only "framed" the front and back - woodglued/drilled/screwed sides, bottom and back to the two "frames" with 3/4" and 1 1/4" screws. the "frames" were 1" x 4" x 8"s cut to the legnths we needed (on the front bottom, we used a 1" x 6" x 8" for added height to keep litter in). The top we "framed with 1". Two "tops" or "lids", again, pre-cut/pre-sanded 11/32, 24" x 24" (cut (2) 8" pieces from the 1" for "handles" on the "lids" and, under lids are (2) 6" pieces cut from the 1" on each end to keep them from sliding off the top). Left 2" open on both corners in the back/top frame for electric cords. It's on casters, and lined with linoleum. Used 1/4" hardware cloth, stapled from the inside on the front "frame". We're using the Brinsea Ecoglow20 for warmth.