Thanks for all your comments i'll take them all into account.
Martyn, oh your a designer and builder that explains why your aviary plans on your website are so good.
I've done some measuring:
After the end of aviary two there is about 8 foot of space we can use.
Thats the maxium space we can use because we have a tree, hill and then behind that a shed so can't go any further.
I'm thinking 6 individual units to house 6 Chipmunks. I'd like to keep the smaller aviary to house Hermione's three daughters (the one they are in at the moment if possible, i think three Chipmunks would need the six foot space) that would be unit number seven. Aviary one would be divided into three sections. Then we'd need another three after aviary 2.
The length of the two current aviaries at the moment then adding on another 8 foot is 24 foot.
So 24 foot is the space we have to use as maxium. Its going to be tight i think but hopefully possible, some units might have to be a little smaller than 3 foot to fit in.
I'm not including Abigail, she will stay indoors, she needs a special cage because of her broken foot. As shes getting older she is finding it more difficult to climb.
We will sort out the outside Chipmunks first and then makes Abigail's she quite happy in the cage she is in at the moment.
Tarcus, with our two current aviaries we did consider perspex but in the end we didn't use any.
Marsha, if we were to use the perspex it wouldn't be on the sides of the Chipmunks living areas we would use it for the corridor the part that would lead to the outside (of course we would only need it if the corridor goes on the front, wouldn't need it for the back). I was considering the roof but am not sure about how hot that could get in summer, we do get sunlight on the aviaries in the summer.
Doghouse, thanks thats what i was wondering. Yeah putting it at the back would probably be better, i see what you are saying. The main thing that it will be used for is to gain access to the individual aviaries so it wouldn't matter if it was behind the aviaries.