I finally have my aviary. It is much more humble than many I have seen on this site, but it is heaven for my four budgies and I think there is enough room for a few more.
I'll post pictures later today, but the brief description is that it is 2.4 x 0.9, but 0.65 of the length is a bird lock. It is up on the decking, so I have put in a wood floor on top of the decking. To prevent needing to mop that too often I have a piece of weed matting that I put on the bottom of the cage to catch the seed and poos. I have several of these so that I can swap them around from time to time. Anyway, if the wood doesn't work I'll move to pavers, or move to the garden and put in concrete. There are several places in the garden that the aviary will fit.
In addition to branches for perches I am also growing vegies in a pot for the budgies - at the moment it is spinach, silver beet and capsicum, the leaves of which they all love to munch on. I also put in native branches from time time - callistamen, eucalyptus, grevillia, wattle.
Being on the decking it is generally a few degrees cooler than outside - mainly because of the elevation. It is about 3 metres off the ground.
Anyway - with 0.9 x 1.75 m how many birds do you think?