Most birdboxes feature a simple design with of six planks ordered in a cube, with a hole in a wall where birds can go in and out. Common additions include a small stick outside the hole on which birds can sit on, and a sloping roof to make rainwater run off. Some can however be highly detailed and decorated, depending on the maker's preferences. They can also be made from things like logs or gourds. They come in many sizes, depending on the size of the bird type the box is made for. Most birdboxes are small, but some, such as ones made for owls or parrots, can be quite large.