Nest Boxes and Structures for Wildlife

Eastern bluebird at a nest box. Many species of wildlife are attracted to backyards and woodlots when artificial nest structures are available. Wildlife use a variety of man-made structures for nesting, sometimes to the disappointment of people. Squirrels and bats may take refuge in an attic, raccoons in the garage, or swallows under the porch roof. Birdhouses have been readily accepted by many natural cavity-nesters, and the placement of houses in your backyard can be an effective way of providing for a number of resident birds.

The supply of nest sites available to cavity nesting wildlife has declined in certain areas due to the clearing of land for development, the removal of snags (standing dead trees) during agricultural and forestry operations, the use of treated fence posts that do not develop cavities, and competition with introduced species, such as the European starling and house sparrow. Nest boxes have been used successfully as a wildlife management tool where surveys have shown that virtually no natural nest sites occur. In Connecticut, eastern bluebird, wood duck, and osprey populations have increased, partially due to the erection of nest structures in suitable habitat. Nest boxes are used by many other wildlife species, such as gray and flying squirrels, screech and barn owls, hooded mergansers, house wrens, and kestrels.

Nest boxes should be properly designed, erected, and maintained for beneficial results. They should also be durable, predator-proof, weather-tight, lightweight, and economical to build. Boxes for a target species should be constructed with the correct dimensions, placed at the appropriate height above the ground and installed in suitable habitat. When constructing nest boxes, do not use pressure treated lumber and do not paint or stain the inside of the box. Whether there are one or 1,000 boxes, they should be inspected annually for needed repairs, replacement, and cleaning. Keeping an inventory of the location of each box and a history of wildlife use will not only provide important information, but will also prove to be a rewarding experience.

Bluebird Nest Box Plans

Bat House Plans

American Kestrel Nest Box Plans, courtesy of Art Gingert

Find plans for Nest Boxes and Nest Structures for a variety of birds through Nest Watch, The Cornell Lab of Ornithology

Dimensions for Nest Boxes and Platforms

Wood Duck and Hooded Merganser

Floor: 9 inches by 10 inches
Entrance diameter: 3.5 inches by 4 inches
Depth: 25 inches
Entrance above floor: 18 inches
Height above water surface: 3 to 20 feet

Kestrel

Floor: 8 inches by 9.5 inches
Entrance diameter: 3.25 inches
Depth: 12 to 15 inches
Entrance above floor: 9 to 12 inches
Height above ground: 20 to 30 feet

Barn Owl

Floor: 10 inches by 18 inches
Entrance diameter: 6 inches
Depth: 15 to 18 inches
Entrance above floor: 4 inches
Height above ground: 12 to 18 feet

Screech Owl

Floor: 8 inches by 8 inches
Entrance diameter: 3 inches
Depth: 12 to 15 inches
Entrance above floor: 9 to 12 inches
Height above ground: 10 to 30 feet

Saw-whet Owl

Floor: 6 inches by 6 inches
Entrance diameter: 2.75 inches
Depth: 10 to 12 inches
Entrance above floor: 8 to 10 inches
Height above ground: 12 to 20 feet

Red-bellied Woodpecker

Floor: 6 inches by 6 inches
Entrance diameter: 2 inches
Depth: 12 to 15 inches
Entrance above floor: 10 inches
Height above ground: 10 to 20 feet

Downy Woodpecker

Floor: 4 inches by 4 inches
Entrance diameter: 1.25 inches
Depth: 9 to 12 inches
Entrance above floor: 6 to 8 inches
Height above ground: 6 to 20 feet

Hairy Woodpecker

Floor: 6 inches by 6 inches
Entrance diameter: 1.5 inches
Depth: 12 to 15 inches
Entrance above floor: 9 to 12 inches
Height above ground: 12 to 20 feet

Flicker

Floor: 7 inches by 7 inches
Entrance diameter: 2.5 inches
Depth: 16 to 18 inches
Entrance above floor: 14 to 16 inches
Height above ground: 6 to 20 feet

Great Crested Flycatcher

Floor: 6 inches by 6 inches
Entrance diameter: 2 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 8 to 20 feet

Tree Swallow

Floor: 5 inches by 5 inches
Entrance diameter: 1.5 inches
Depth: 6 inches
Entrance above floor: 5 inches
Height above ground: 6 to 16 feet

Black-capped Chickadee

Floor: 4 inches by 4 inches
Entrance diameter: 1.125 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 6 to 15 feet

Tufted Titmouse

Floor: 4 inches by 4 inches
Entrance diameter: 1.25 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 6 to 15 feet

White-breasted Nuthatch

Floor: 4 inches by 4 inches
Entrance diameter: 1.25 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 12 to 20 feet

Carolina Wren and House Wren

Floor: 4 inches by 4 inches
Entrance diameter: 1.125 inches
Depth: 6 to 8 inches
Entrance above floor: 6 inches
Height above ground: 6 to 10 feet

Eastern Bluebird (Plans for building a bluebird nest box)

Floor: 4 inches by 4 inches
Entrance diameter: 1.5 inches
Depth: 8 inches
Entrance above floor: 6 inches
Height above ground: 5 to 6 feet

Prothonotary Warbler

Floor: 5.5 inches by 4 inches
Entrance diameter: 1.25 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 6 to 15 feet

Gray Squirrel

Floor: 10 inches by 11 inches
Entrance diameter: 4 inches (entrance on side of box)
Depth: 24 inches
Entrance above floor: 20 inches
Height above ground: 12 to 30 feet

Flying Squirrel

Floor: 6 inches by 6 inches
Entrance diameter: 1.5 inches
Depth: 8 to 10 inches
Entrance above floor: 6 to 8 inches
Height above ground: 10 to 36 feet

Open Platforms

Phoebe

Floor: 7 inches by 8 inches
Depth: 8 to 12 inches
Height above ground: 8 to 12 feet

Barn Swallow

Floor: 7 inches by 8 inches
Depth: 6 inches
Height above ground: 8 to 12 feet

Robin

Floor: 7 inches by 8 inches
Depth: 8 inches
Height above ground: 6 to 15 feet

Content last updated in April 2026.