I'll post some of the things that my chickens have seemed to enjoy over the years. Some are important and some are just nice for the chickens, although not necessary.
From the chickens point of view, there are a lot of things they like:
They like enough space, so they aren't crowded, crabby and picking on each other.
They like litter that isn't wet and stinky. Making the coop easy to clean helps a lot, as well as having a corner to store some clean shavings for easy access. I keep a feed scoop right in the shavings, to make it easy to add a bit where I need it. Keeping the litter well managed also improves air quality. Badly managed litter gives off a lot of ammonia.
They like air that isn't stuffy, damp or over-heated. Good ventilation takes care of this. If your summers get hot, they need a lot more air flow then. You shouldn't place their roosts directly in a draft in the winter. It's good to have winter ventilation up high, above the level the chickens are roosting at. It's ok to have a breeze in warm weather, once they are feathered out and not babies anymore.
For a roost, they like a 2x4, wide side up, with the edges gently rounded. Other roosts work, too. Place the roosts at least a little higher than the nest boxes or they may roost in or on the nest boxes.
As layers, I think they do well with nest boxes that are big enough to comfortably fit more than one chicken in it. This is because they all want to use the same one, even if there are lots of others available. I am a fan of community nest areas or at least building "double wides" for boxes.
They like food all the time and fresh water that's changed regularly. They always run over for fresh water. Even if they also drink out of mud puddles.
They love to look out windows that are at their level. That includes higher windows, with a little shelf or platform in front of it. Ours like to look out the windows during breakfast and on days when the weather is very bad. They'll also stand around and look out the pop hole door. Windows make the coop a nicer place during the day, if you live in a place with harsh winters.
If you get a lot of heavy rain or snow, I think they also appreciate a little "chicken porch" for their coop. Just some type of roofed area, right outside the pop hole door. Then they can hang out in the run, even if it's raining hard. It also gives them some shade in summer. It also keeps you from having to shovel snow in the winter, to get the pop hole door open. You can either roof a section of their run right next to the coop or have a little roof coming off the coop.
Anything you can do to make the coop easier to care for, is a huge plus for you. Have fun with your chickens and
my best tip would be keep it at least 40 cm off the ground then you don't get mice and rats living under it and the chucks like to shelter underneath when it is both too hold and wet and windy. that is what i have done with mine and the chucks love it.
