Our 7X12 "Garage Addition" was built in 2008 when our family first became backyard chicken keepers. Building it on to the garage meant we only needed to build 3 walls, and the garage was a great "anchor" to make the coop solid. The project was also a good learning project and a great experience to share with 'the boys'.
the boys and I cleared the ground space... that one root was stubborn
We built the footers & deck, then began to frame the walls - including windows with chicken wire
Adding exterior panels and roofing was pretty easy, and the boys even found a new place to rest
Finally, add a door, trim and paint and the coop is solid and safe for the birds
the interior has been an on-going project... there always seems to be something "tweak"