My Breeding Facility
All the parrot breeding cages and flights were custom built by Corners Limited in Michigan. Pictured left are 5 foot modular stacking units with framed doors, heavy duty guage wire and fixed grate floors. Made from aluminum tubing, they are light weight and very easy to move on their casters. I had a solid sheet barrier placed between the upper and lower unit so no toes would be comprimised. They have a lazy susan style swing out feeder system... keeps fingers safe!
My cockatiels have a room all to themselves with an air cleaner system that vents to the outside as well as a floor Hepa filter air cleaner. Cockatiels have a lot of feather powder that is hard on the lungs if constantly breathed in.This close up is of one of the two 6 foot stacked flights. This is where my resting birds hang out, practising flock behaviours and await their turn to breed!
End and front views of the 4' double stacker, also custom built by Corners Ltd. The upper level houses the juveniles, playing together while they grow and mature. 
~ Before breeding, males must be yearlings, and hens must wait until they're at least 18 months of age. I've found birds allowed to reach at least these ages make better parents.
-------- >
6 foot flights. Upper houses mostly hens, lower is for boys only! Note that 90% of my breeding males are standard greys!
The lineolated parakeet breeding unit can house 8 pairs with a solid divider between each set of two, or 4 pairs without the barries. I've found through trial, that my linnies seem to prefer, and indeed breed better, in cosier breeding quarters.The pairs without nests have had their allotment of clutches  for the year and are on vacation! Each pair has pellets and fresh water at all times. Breeding pairs are offered rice and bean mix with finely chopped hard boiled egg and sprouts daily. All pairs get a plate of mixed small seed with cubes of fresh fruits and veggies daily as well. Iodine blocks and cuttlebone are provided. I don't offer any of our hookbills grit or oystershell as they hull their seed and don't need this in their gizzards to grind up seed shells. (This is needed for birds that eat their seeds and all!) Grit can cause compaction and even death in hookbills. 
This unit is from the Italian company Ferplast and is great for any number of species. I've had linnies, cockatiels and senegals housed in this one. The bottom can be divided in half if desired. There's nest box doors on both sides of the upper and lower unit.

A close up of some tiels in               the 4 ' flight. 

Left:   whiteface cinnamon                 heavy pearl pied,                       "Aspen"

Center:  grey / pied male, 

Right:  whiteface recessive                 silver pearl pied
            (note the red eyes)