What the Experts Say About Birdhouses

While there are varying professional suggestions for the interior dimensions and mounting locations for birdhouses, experts agree on some general birdhouse basics. There are many adorable painted wood birdhouses on the market. Those are better suited for garden decorations than for providing appropriate shelter for birds. The most important features you should look for when buying a birdhouse are:

Entry Hole Size
The most common hole diameter is 1 ½”. While some birds prefer a slightly larger or slightly smaller entry, this size is sure to attract several species.

Perch-free
Birdhouses are intended to imitate a natural environment such as the hole in a tree. Perches are an unnatural distraction and attract predators.

Natural Wood
Birdhouses should be constructed of at least 3/4” thick wood in order to provide an insulated environment. Exceptions to this include Purple martin houses which may be constructed partially or completely of metal. The wood should remain unfinished, free of stain and paint.

Floor Size
The floor of the box needs to be cozy, but large enough for chicks to develop. While some species prefer a slightly larger floor, the most common size is approximately 4” x 4”.

Height
The distance from the floor of the birdhouse to the entry hole should generally be no less than 5” to create maximum space between the entry hole and the growing chicks.

Ventilation
Ventilation slits across the top of the box panels are important to allow hot air to escape. A screen between the nest and the floor also helps to prevent mold and insect infestations.

Roof Overhang
The roof should overhang the entrance hole by at least one inch to offer shade and to prevent rain from getting inside. A small drip edge in the roof will also help to carry rain away from the entry hole.

Drainage
There should be drainage holes at the bottom of the box to allow moisture to drain from the birdhouse.

Entry
You must be able to open the birdhouse for monitoring and cleaning.

Keyhole
A keyhole or bracket must be included on the birdhouse for attaching it to a tree or pole.