So here's another engineer with lots of chicken experience to back up my recommendation.I was about to leave to go buy 4 more for a total of 10. Really positive I should only go with 4sqft per bird? Final answer?
That would give me 7.5 birds. Lol. Call it 8. Is that really what you guys recommend?
WAIT!!! You don't need more chickens.
If you decide to push the limit of your coop's capacity it's the chickens that will pay for it.
Unless you have a fully predator proof setup like below that can be winterized (like below) you want to have a MINIMUM of 4 sq ft per bird in the coop.
You cannot ignore any of the seasons your flock will be exposed to.