building avery for african grey

Question
how big must the avery be to house a breeding pair of african grey's, at what age are the bird's best to breed.

Answer
hi. thanks for your question. i am assuming that you are asking about how large of an aviary to build/purchase for a breeding pair of African greys. the general rule of thumb is the larger the better. so the biggest size aviary that you can afford and accommodate would be the best, especially since African greys are rather large. individual greys need at least a cage the size of 3 x 2 x 4 feet tall and that is just for individual greys, so double that and you'll see the MINIMUM cage requirements for a breeding pair.
in regard to breeding age, African greys come in to sexual maturity and are able to breed in a healthy manner by about age 3 years (males and females).
on a cautious note, it sounds like you may be new to African Greys. i suggest owning a solitary grey for several years and reading as much literature (online but also purchase a bird book at a vet, bookstore, online etc.) before even attempting to breed them. African greys are large and intelligent birds that require much attention and care. 2 African greys need twice the attention. and 2 African greys plus babies will be a full time effort for even a professional breeder. in order to properly care for the babies but also adequately care for your breeder pair, it is imperative that you are fully prepared to possibly raise the chicks yourself and be prepared to care for the two breeder greys during their normally very long (50 years plus) lifespan.  
i hope this helps. alicia