There are many ways to get free lumber to build coops with. If you live anywhere near any new construction, go by and talk with the builder and ask if you can salvage any lumber from them. 2x8, 2x10 2x12 are often used for concrete forms. Once they have concrete on them, they can't be used in the framing of the house and can't be returned to the lumber yard. But the concrete is easily scraped/knocked off and woudn't hurt the chickens anyway. Often times they just trash them. Often times they will use 2x4's for bracing and then not use them for anything else. Or you might find 6' peices. All lengths. You might have to remove some nails but that's a small price to pay. Also they often have partial sheets of siding, window cut outs etc. You might have to get creative in how you put them to use but, again, can't beat the price. Go by when they are roofing and you can often pick up partial bundles of shingles for free. Don't forget to check their dumpsters (if they have one on site). With lumberyards, they will not take anything back that has been cut or nailed. Also, often you can get used pallets from lumber yards too. Sometimes they are even OAK!. At this point, we have our coop framed and sided (still have nest boxes and such to build and cosmetics) but so far it has cost us nothing but our time and sweat. And it is 8x8x 11 at the front and 8 at the back. We have enough lumber to build the attached 8x6 feed shed as well. We have enough shingles and tar paper to do the roof with. We even managed to get enough electrical wire to reach from the coop to the power box...again, free. My very strong advice though is to MAKE SURE YOU HAVE WRITTEN PERMISSION FROM THE BUILDER (not just the framing crew). You wouldn't want to be mistaken for a thief. Hope this info helps.