Roosting bar height

Please advice. I read everywhere that roosting bars must be higher than breeding boxes.

My main question is this really nessary especially when i wil be closing nesting boxes at night.

Reason for asking is it will be in a hot climate so i want plenty of ventalation so don't want to make solid walls for coop to high so can have good airfolw over the top.

Will be a retangular shed one side layer coops with day area for each coop, other side coops for boiler chickens. Predomenint wind is from more layer egg side which wil also be south side, im in souther hemesphere so more shade in day areas.

In my experience, chickens like to sleep up high. The risk you have with having nesting boxes up high is that your hens will think it is a nifty spot to sleep in which in turn means they are going to manure in the boxes.

If you are going to block off those boxes, then I wouldn't think it would be much of a big deal.

I know that I cannot reliably go the the chicken coop each night to block off nesting boxes, and consistently go to the coop before sunrise to open them up again. Therefore, I find it easier to provide roosts just under the rafters of the coop.

My coop/run combo sounds like what you are thinking of doing. 24'x24' deep bedding in all of it. I have half under roof and 12'x12' of the roofed section with walls on the N,W,E side and open on the south. The solid walls are 7' high then about 2' of 2x4 welded wire fence, then the roof. All the heat goes out through the top and it stays cooler than otherwise in the hot humid summers. I do not provide supplemental heat in the winter and everyone does just fine.

When I first built it, I had a 6' section in the 3 sided part that I put 3 roosting bars. I do not think a chicken has every roosted on the bars, they fly all the way up to any open rafter or horizontal tie and roost there. I always get a laugh when I look over at the roosting bars. They have turned into a ladder to get up to the highest possible parts of the coop.

My 2cts worth, 40+ years having birds never put in roosting, poles bars, whatever. I put chicken wire over nests to the ceiling to keep the birds off the nests.  Chickens flock up on the floor, make it through the night .  I build the nests 18" off the floor litter, 24 from the plywood floor, nests 18h x 16W x 12D, 2 high, birds get in and out which ever level they choose fine