I think you have some really great ideas going on!! And so many people have already given you such excellent advice already, so you may already have enough info, but I thought I'd chime in anyway...
I know your wife says 6 now... buuuuut.... once she names all the birds -and loves being entertained by them -and sees how much the kiddos love them (maybe 4-H in the future?) -and enjoys those fresh eggs -and wants a more colorful egg basket-and misses having little fluffy peepers around -and realizes they are rather therapeutic -and maybe loses one to something unexpected -and so on... you may "accidentally" end up with more than planned. It's called chicken math. You
can avoid it... probably.
Just curious as to what is your end goal? To have chickens as a homesteading (eggs and/or meat) venture? Or to keep them as pets for their entire lives? Keep in mind that egg production will dwindle or stop for the winter after year 2, and will probably slow to "not much at all" after a few years. You may want to consider
flock rotation if you want chickens for other reasons than just pets.
I completely understand about space limitations, I live in the burbs too, and had to build my coop accordingly.
Mine is 3x6 and I would highly recommend going 4x8 if you have the opportunity! Though I really do love my
poop tray under the roosts as it leaves the entire coop floor available as living space, it's super easy to keep clean and underneath also doubles as a temporary brooder for new babies. This is part of what it looks like during the integration stage.
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Also, if you plan to build your run completely secure and covered, you can keep food and water there too. I use 3' tall
gravity feeders to save space.
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My coop is raised only 19" and I wish it was at least a foot higher for easier access, but I can still manage. My chickens love to spend time under there too like
@BY Bob says!
You can take a look at my whole building process and other coop features if you'd like:
https://www.backyardchickens.com/articles/the-mod-coop.74256/
Have fun finalizing those plans over the winter!!
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