Hi and welcome! I feel I can help you a bit, we have six hens and we have a 6x6 coop with an attached run that is 6x15. We have 3 Barred Rocks and 3 EE's. We also live in western Washington, so fairly similar weather. I personally wouldn't go smaller then 6x6 with 6 heavy breed hens, it looks big enough until you see them all standing in it with there food and water and nest boxes, then it becomes very small. Especially when the weather is unfavorable and they don't want to go outside for days. My opinion would be less hens or a bigger coop. And believe me when they talk about chicken math, it is completely true. We have only had our chickens for 10 months or so and already we are trying to talk my hubby into a bigger coop and more chickens! They are so much fun! Best of luck, you are already ahead of the game by asking these questions before you have those cute little faces staring at you! Way to go!
