Size/Style
Cockatiels need to have a large bird cage, because they are very active parrots, which like to do a lot of flying and climbing inside their cage. The minimum size you should consider is 20 inches wide, by 20 inches deep, by 26 inches high. The best style of cage is one with horizontal bars to assist in their climbing activities. The gaps between the bars should be less than 3/4 of an inch.

Cage Accessories
Cockatiel cages should contain lots of perches of varying sizes and textures. This will help to keep their legs, feet and beak healthy and strong. You should also make sure that it contains several toys to keep your pet amused.

Location
Strong smells such as insecticides, smoke and air fresheners etc… can very easily damage a cockatiel’s respiratory system, and may even kill him. Something as simple as over-heating a Teflon pan can give off a gas that is fatal to cockatiels. Therefore, where you locate the cage is really important. You need to ensure that it is located away from any such odors, and also away from any drafts, because cockatiels like to keep warm.

At Night
Make sure your cockatiel cage is covered to prevent any drafts, and to allow your cockatiel to get a good night’s rest.

Post from the Parrot Care Made Easy blog. The resource for all things parrot - e.g. parrot training, parrot food etc...

Cockatiel Cage