I've build several coops now and have 1 suggestion. Make your bins at waist level so you don't have to bend over all the time to get eggs. My new one for 35 hens has 10 bins of which they lay in 4. Figures. I made a ramp for them to walk up, had to staple chicken wire to it for traction. If you would like pictures I can go take some. It's alittle over the top...we joke about our 3 coops...Becky's first one is " The Ghetto"...very primative..4 feet high and 5 wide 4 bins. The newer one was 8x 4 x8'with bins at one end 4 bins on 2 levels ( The Condo)...Then I got tired of bending over and Built " THE EMBASSY SUITES", made it as an addition to the condo but 8' by 8' with an 8' ceiling for storage. They love it. The bins wrap around 2 sides with a walkway and roosts on top.
The door is tied to the old coop which I will make into straw storage when I have time.
PM me if you want pic's
Chickens prefer to lay in each other's nests but with 35 chickens they should be laying in more than 4. I've found that if the size of the nest box is a little restrictive for the size of birds the less nest boxes they use. Small (bantam) and medium (ie Mediterraian) breeds should have a nest box of either 14 or 15 inch cubes. Larger Breeds (Multi-purpose and meat) need a nest box at least 16 inch cube and small turkeys should start at 18 inch cube.