I have a coop kit I got on sale at TSC and it's a little bit smaller, maybe 3x3, and a smaller run we removed, inside of a 6x12 dog run. I noticed they seem to fight more. They don't free range though so that's part of it. I'm planning on building a bigger coop and run in the spring though. It's going to be 4x8, which is sort of the minimum for 8. The run will be big though. I know a lot of people who do keep them in smaller quarters or who simply have a "huddle box" for sleeping and laying and sure, all 8 fit in mine, but they don't necessarily like it. You also have to think about how much they will be in it. Mine are in theirs all the time because they hate bad weather so that adds to the problems so in the new run I'm going to make sure it's roofed and/or in really bad weather the sides will be covered so they don't have to be cooped up inside. Yours are free ranging and likely will only be inside to sleep and lay eggs so it might be fine but you also have to think about what if they can't get out that day, will they be happy? Usually the minimum recommended square footage per bird for inside the coop is 4 square feet per bird which would mean that could hold 3 butcommercial standards are only 2 square feet. But Orpingtons are big birds. However yours are free ranging and people do fit more in smaller coops if they're going to be free ranging or have a bigger run so it could be fine.
Also I hope you don't think I'm being mean or anything, I'm not trying to be, just trying to inform/help others because we made the mistake of getting a smaller coop. I had wanted a bigger one but my parents wanted something quick for the chicks so i agreed and this was on sale and looked much bigger in the pictures. Now we're having to upgrade. Yours looks better built and bigger though, ours was Chinese made and we had to put it together ourselves
Also I hope you don't think I'm being mean or anything, I'm not trying to be, just trying to inform/help others because we made the mistake of getting a smaller coop. I had wanted a bigger one but my parents wanted something quick for the chicks so i agreed and this was on sale and looked much bigger in the pictures. Now we're having to upgrade. Yours looks better built and bigger though, ours was Chinese made and we had to put it together ourselves