Plan, plan, plan, and then plan again...... the little details are what will annoy you the most when you're done.
Plan locations of everything from where feeder will be, where water will be, how you'll get power in there if you'll be using some kind of
water heater... roost heights and locations... poop boards, or no... will you smash your head on the roost every time you go in to clean it.
plan plan plan.
Make it easy for you to get in and clean... big "people" door, high ceilings... lots of floor space for them...
MOst important.. plan everything around the ventilation. START with that. Decide how much ventilation you'll need, and where it will go,
and adjust your PLAN to work with THAT. Remember you don't want any direct drafts blowing on your chickens in the colder months,
so make sure your venting isn't blowing directly on them at night... or that you can close off the vents that DO blow on them
for the winter, and still have proper ventilation. see this:
https://www.backyardchickens.com/web/viewblog.php?id=1642-VENTILATION
I went a little crazy with the framing, and blocking in between studs, and when it came time to paint inside, I wish I had not been so
intense. but it sure is STURDY.
https://www.backyardchickens.com/web/viewblog.php?id=59508-the-building-of-the-coop
Use a nice gloss or high gloss paint for ease of cleaning....2 coats, and keep chickens OUT until all smell of paint is gone. I used exterior grade latex.
Am I rambling yet?