Coop design thoughts please

We are currently in the process of building our first coop and I am trying to figure out a few design features or details that I am hoping you all can help me with. So our coop is six feet tall, and it is 8ft(width)x12ft(length) it will have six windows three down each long wall for now, we may add one by the door so I can look in without opening the door up. The windows will be roost height so the chickens can look outside if they haven't been let outside yet.

What I am trying to figure out is how I want to do the roosts. I do want poop boards under my roost to help keep the coop clean, and I know I want the roosts about four feet up so that the boards are easy to clean. I am just not sure how long the roost should be, or if I should build a ramp up to the roosts? I thought of doing a two tiered roost/poop board, so half would be four feet high and then the other half would be like a foot and half or two feet lower for the heavier birds. Does that sound like it would work, or should I just do all one height? Also would it make sense to have the nest boxes under the poop boards? I am just trying to figure out the layout for all these things and am having trouble picturing it all and how it will lay out.

Also in case it matters I have eight chickens they are mostly heavy breeds, I have a few buff orpingtons, a couple Plymouth rocks, an australorp, red sexlink, Columbian Wyandotte and a salmon fav.

You won't need a ramp to the roost, they'll 'fly' up & I think 4' roosts are good. I personally worry about going too high with the heavy breeds, don't want them injuring their feet/legs from the 'shock' of landing. You'll need to figure out the flooring, are you on the ground or adding a floor? What kind of material are you going sand or DLM?

Hubby made my Run/Coop 8' x 12' x 7', I had 4 (2 RIR & 2 EE) which I feel is 'just enough' room whereas anymore would be "crowded", my standards I live on the Big Island so our weather isn't severe, just a lot of RAIN. We got shade cloth on the windward side & back due to winds/rain, got shower curtains (EMT rods) all the way around. Works great.

The chickens sleep on the roost (after thought) above the dog house (nest box) which is about 5' with poop board under it. The other two are about 3' & 4' off the ground. Hubby decided they needed stairs to the "nest box". Under the dog house they have their dust bath with top soil, DE & PDZ. I went with the DLM & love it, I scoop the poop board & pick up any big ones in the shavings, add more shavings as needed, the used stuff I toss on my plants. They are let out to roam the fenced yard in the afternoons when I'm home & "go to bed" in the evenings.

I also feed them FF so there's no mess or waste & they do drink less water (ACV in that). I'm sure others will be peeping in with alot more ideas. Enjoy!

I knew they could fly up, they fly well at six weeks, I was mostly worried about them getting down without hurt themselves, lol. There is a wood floor right now and then we will add at least 6 inches of shavings, probably more on top of that. They will also have their run during the day.

Thanks for the input and the photos, I like your set up. We get a lot of rain and wind here in WA too. Its just so hard when you are first starting out and have no experience to go on when building your first coop. Now I am wondering if DH should put caulk between the boards on the walls to help seal them a bit before painting so there aren't any drafts from cracks.

Don't hold me to this but I've read that the wind draft is worst than the wind factor, if the cracks aren't too wide, paint will seal the cracks. Yet ventilation is a BIG must, another thing I've read somewhere. Hear you about first time coop but we learn & with chicken math end needing another coop/run, ha ha. I'm thinking of getting the Coop & Run combination kits selling at the feed store to add bantams too....Just haven't told Hubby yet Enjoy

Just on the question of the perches, I was looking at some youtube videos of people's setups and coops. One lady showed her perches and said that she had chosen to do parallel ones because she had read that they might fight over tiered ones. With 8 chickens and plenty of room I don't expect you'd ever get much fighting, and I don't know whether her information was accurate, however for what it's worth thought I'd mention it.

Personally, I wouldn't put the nest boxes under the poo place. Their aim might not be what you want and I find that animals can manage to poo where you don't want them to.