I like your building style, efficient but relaxed. In some ways it reminds me of mine.
When I'm baking a cake I carefully follow a recipe. When I'm building for chickens I free lance. I don't follow any square foot per chicken rules, there are way too many variables for things that precise to really apply. The 4 and 10 is a good starting point when you have a handful of chickens where all of them are mature and they are already integrated but not when you are getting ready to integrate.
If I were in your position I'd build a totally new coop, a little bigger than the minimum size. If you are in the States most building materials come in 4' and 8' dimensions so if you are buying new I'd use those as a base. If your standard dimensions are different I'd use what's local. If you are recycling materials look at what dimensions you have.
I'd keep the old coop at least temporarily in case you need it to house the new chickens during integration. Having something separate like that can come in really handy if you ever have to isolate an injured chicken. It just gives you more flexibility. While you can extend that often building new instead of modifying is less frustrating.
In my opinion you can keep maybe eight or nine chickens in one of those small elevated coops. Any more than that and the coop gets pretty big for you to try to reach everywhere inside. People manage it with lots of doors so it can be done, but I think that's when you need to start thinking about a walk-in so you can each everything. A 6' x 10' isn't bad, the two feet cut-offs can usually be used for nests or such. Now is the time to plan for your maximum flock of the future instead of gradual growth.
Good luck!
When I'm baking a cake I carefully follow a recipe. When I'm building for chickens I free lance. I don't follow any square foot per chicken rules, there are way too many variables for things that precise to really apply. The 4 and 10 is a good starting point when you have a handful of chickens where all of them are mature and they are already integrated but not when you are getting ready to integrate.
If I were in your position I'd build a totally new coop, a little bigger than the minimum size. If you are in the States most building materials come in 4' and 8' dimensions so if you are buying new I'd use those as a base. If your standard dimensions are different I'd use what's local. If you are recycling materials look at what dimensions you have.
I'd keep the old coop at least temporarily in case you need it to house the new chickens during integration. Having something separate like that can come in really handy if you ever have to isolate an injured chicken. It just gives you more flexibility. While you can extend that often building new instead of modifying is less frustrating.
In my opinion you can keep maybe eight or nine chickens in one of those small elevated coops. Any more than that and the coop gets pretty big for you to try to reach everywhere inside. People manage it with lots of doors so it can be done, but I think that's when you need to start thinking about a walk-in so you can each everything. A 6' x 10' isn't bad, the two feet cut-offs can usually be used for nests or such. Now is the time to plan for your maximum flock of the future instead of gradual growth.
Good luck!
