Anyone using a shed and converted it to a coop?
Yes. It works wonderfully.
I got a 10x14. The chickens get 10x8, there is a garden-fence wire divider with a door made from an old screen for a doorwall (aka sliding glass door), and the rest is a storage area for the chicken supplies and the garden tools/supplies.
It is also really nice to be able to go in and shut the door behind me before opening the door to the chicken's area. Especially when bringing in bedding or feed.
It also allows the possibility of expanding the chicken's space either permanently or temporarily (like for raising chicks).
I had one custom build by a business that does nothing but build sheds. I had two good choices of such businesses. One was the winter job of an Amish guy and his friends. The other was a family business that builds year around.
We also looked at all the options at Lowes and Home Depot.
We went with the Amish. The other custom builder was our second choice.
Both would make the modifications we wanted - the overhang to the roof, the open eaves, the extra big door in the side so the chickens have a three-siding coop (inspired by the Prince T Woods' coop design), two fairly big windows in the back, and a large double door in the front. The front doors are to leave that side open also if I want to and to fit a riding lawn mower in easily if the shed is ever used for only lawn and garden storage.
We went with the Amish builder because I liked the board and batten style better than the plywood the other shed building company used. This Amish builder bought logs from a local logging company and sawed the boards himself.
Some of the lowes/hd sales people said they would make modifications but they really didn't make that kind of modifications. We considered buying a standard one and making the modifications ourselves but it would have cost much more than the custom build options even if we didn't count our time or hassle.