Hi! Chickens are so fun and I have learned soooo much since beginning two years ago! I researched all over this site when I was ready to begin and found so many knowledgeable and willing-to-help folks here.
Anyway, my coop is a 6x8 ft insulated shed that I added 4 vents and a window to. I also added an automatic pop door that opens at sunup and closes at dusk. My run is 16x24 feet enclosed, and divided down the middle with the intention of being able to close one side to allow grass to recover if needed. It has not been needed yet, but that is likely due to the crew being allowed to free range all day. I very rarely have to close the run door. In fact, the only time I have closed it is when I've just planted my vegetable garden and had to give the crops a few weeks to grow and become established before the chickens discovered them.
I have 12 chickens now (2 of them are roosters), and there are five more pullets in the brooder. They have two 8 foot roost boards, at different levels, which works for them. There is enough room for all of them on the higher board, but some choose to use the slightly lower board. In my situation, I am confident the chickens all have ample space, because they are in the coop only to lay eggs or roost in the evening. I live in North Dakota and they choose to run around outside even in the freezing weather. When it's windy, they generally stay in their run, or close to it, where there is protection.
When I first got my chickens, I was not sure how my 3 dogs would react to them and they were locked up in the run continuously for the first couple months. Eventually, I found that my dogs really had no interest in harming them and they've been living harmoniously for 2 years. I have a labxhusky, a full blooded, working German Shorthair, and a full Portuguese Pointer, and they are protective of my flock.
I guess my point is, all of our situations vary one from another. There are people who would NEVER put 17 birds in a coop my size, but they may have a different set up than I have. And likewise, what works for someone else may not work well for me.