The right hand door is again a simple lap-jointed rectangle. However, in order to be able to attach hinges, there needs to be an upright attached to the horizontals with a dado. In my case, the hinge upright is located 12 inches from the right frame upright. The left-hand door is immediately hinged to the frame upright. The reason for this small door is that it allows you to open up the cage to put food or other items inside with less risk of birds escaping.
Birds prefer to fly out through the top rather than the bottom.
Across the bottom frame a piece of wood is screwed to serve as a good rest point for the cage. On these shelves various bird items can be stored. One final remark, I have found that my Pekin robins are quite happy in this cage and, in fact, they often try to fly back into the cage when they are in the aviary. Dimensions are given as a point of reference. They may need to be changed, depending on what stock is used.