Haha, so other people have the same idea to combine deck and aviary.
We've built the deck over the whole width of the house just like as you Whithney plan to do, it is almost 9 feet high. Underneath we built in the aviary, I think it is 25x40x9 feet so it is quite a big thing.
I wanted different grounds and so we put in a grass area, there is a big area that is concrete (was there already when we bought the house) and onto the concrete, we've added a big self made 'flower bed' which is 8x8x3 feet. In there, I've planted three different kinds of bamboo for the birds to climb around and chew on it. Bamboo is a very fast and aggressive grower, the concrete underneath it gives it the borders so it does not grow out of control.
I've planted two different kind of banana trees which both supposed to be hardy even up here in MI. They both died at the first couple of frosts (learninglearning, always learning not to believe everything) in which I am still very disappointed since I was so happy for the birds to have the fast growing trees to work on and also to have bananas that they would be 'harvesting' by themselves, almost like in free nature. Oh well, it looks like this one is not going to happen.
We've added some bobwhite quail as 'ground maintenance'. They do a great job in cleaning all the leftover nuts, fruit, veggies, pellets etc. that fall down from our messy eaters, less to clean up for me and the aviary is free of ants and other insects. These little guys add a lot of living to the aviary and our birds don't seem to have any problems with the little guys.
We choose the bobwhites because they are a native species to MI so they can live outside all year long and we can relieve the future babies back out to nature instead of have to sell them or take all the eggs out from the parents.
My husband built feeding systems/stations that can be operated from the outside (they turn 180 degrees). This way we don't have to be concerned for the case that out of whatever reason someone else has to feed the 'beasts'. They can do it from outside and don't have to go in there. Most of our friends are not very comfortable around the big birds, so this makes it so much more comfortable for everybody.
In the moment, the water is provided by bottles from the outside but I want to put in a large bolder with a flowing system, a little pond and maybe a waterfall. Just have to find out how to keep it clean and what filter systems ect. to use.
There is a sprinkler/misting system installed but still, I think the birds would love to take baths in that little pond.
We try to make the whole thing as self efficient as possible. This will for sure not relieve us from supervision but it still takes a lot of work away.
There are still so many ideas and projects that we want to add, so I am very excited and hoping for a lot of posts and pictures here.