I plan to build my own coop to house 7-15 chickens but have no idea how to get started. Don't want to buy a prefab but having a hard time finding actual plans. Any help/suggestions would be greatly appreciated.
Hello and welcome to BYC! Glad you joined.
Convert an old shed into a coop.
That is what I did.
Before and after.
If you are looking for a coop for "7 to 15" chickens, convert something that is 8x8 or 8x10. You sound like a potential chicken math victim.
I do have a layout sketch in the article I wrote for the above shed to coop conversion along with basic framing details. The coop articles can be found here. You'll want to look at the large or medium designs.
Your run should be 15 sq ft per bird in size. Build larger than you think you need.
Good luck!