I read deep bedding can be used but admittedly don’t understand the difference.
Moisture and composting qualities. Deep bedding is a dry system that isn't intended for composting in place, deep litter requires some moisture (and optimally microbes, insects, worms) in order for the litter to compost in place.
This is an example of true deep litter in a run:
As you can imagine this is neither good for a wooden coop floor nor is the extra moisture good inside a chicken coop in general. Deep litter coops tend to have dirt/ground contact floors.
The run will also be 8x8, it will be below the coop. We could make it 8x10 to bump out backwards if I give up a little of my planned garden space.
So an elevated 8x8 is tricky, I think you mentioned having access hatches around the sides of the run? That would definitely be needed both for maintenance and so you can retrieve eggs or sick birds from under the space, as it's quite deep to access without those hatches.
I'd actually recommend shrinking the coop, for 6 even with cold weather considerations you'd need maybe 48 sq ft in coop floor space, and you have 64 sq ft allotted. That'll reduce the amount of under coop space you'd potentially need to access, and give you more vertical space in the run to add roosts or taller clutter for enrichment.
8x10 would of course be a better run space overall. Birds will never say no to more run space.
There will be an access door inside the coop with a ramp to climb down into the lower run, there will be further run space behind without the coop over it. The specs I’ve given allow more than enough coop and run sq footage space for 6 chickens. I don’t understand the problem?
You have enough space for 6 most likely, just going by averages. Some birds tolerate confinement better than others, some less.
I don’t see why access from all sides is essential if my 2 access points allow me to clean it out and even climb in it if necessary to address any issues. I also figured those two items would serve to break some wind and allow further “insulation”.
As others have mentioned it's because you still need to be able to access both sides of walls, fences, etc. for maintenance. IMO you'd almost be better off actually building the coop into the fence (if that's legal) by using it as part of the wall) than having a separate wall in close proximity, because that at least gives you inside/outside maintenance access to the whole structure (coop / fence).
The pop door (I like that) could go in either the floor or the back wall. I will be using a pulley system to open it. I was planning the floor but either work.
Floor pop doors are not ideal. It doesn't sound that problematic until you put it into practice, but the main problem is that it's hard to prevent bedding from falling out of it all the time.
Also I don't think most auto doors can be installed on a floor. Maybe you don't intend to ever get one, but it might make it hard to find one if you decide to get one later.
See and here I am thinking the opposite since the access to clean a raised coop was at waist height and I’d basically just pop open the access, rake stuff into the wheel barrow, less bending. Lol
If the coop ends up 8x8 you will not be able to reach anywhere near back corners without physically climbing in or stretching quite a lot.
As someone with chronic lower back issues, I'd personally recommend walk in coop, walk in run. My coop clean out is done completely standing upright by just stepping in and raking/brooming all the material out into the run.