How to Build a Bluebird House: Nest Box Plans
Bluebirds are as beneficial as they are beautiful: they prey on large numbers of moths, caterpillars, crickets, and other bugs. The bluebirds visiting in our yard often perch on a tall garden post and on the roof the nest box, then swoop across the yard to snatch a flying insect from the air. Because they are cavity nesters, bluebirds look for abandoned woodpecker holes and other natural crevices to build their nesting sites.
They prefer open fields but as farmland gives way to urban sprawl, these beautiful birds have an increasingly difficult time finding suitable, natural tree cavities or abandoned woodpecker holes for raising their young. They also suffer from competition with the larger starlings and sparrows, who will drive the smaller bluebirds away from potential nesting sites.
Fortunately, bluebirds can be attracted to backyards where they will nest in birdhouses built to proper specifications. This house is a simple and inexpensive project to build and can be made from pine, cedar, or redwood boards that are commonly available at home centers and lumber yards. The entrance hole for eastern bluebirds is 1-1/2" in diameter, letting the bluebirds in but keeping out the larger starlings. If you're building a nest box for western or mountain bluebirds, the entrance hole should be increased to 1-9/16" in diameter.
The Cutting List:
Cut a pine, cedar, or redwood board into the following parts:
- Front (part A): 5" W x 9-1/2" L
- Back (part B): 13-1/2" W x 5" L
- Sides (part C): 10-1/2" W x 4" L (Qty =2)
- Roof (part D): 7-1/2" W x 7-1/2" L
- Bottom (part E): 4" W x 4" L
- Entrance guard (Part F): 3" W x 3" L
This basic nest box is easy to build. The bluebird house plans (below) show how the pieces fit together.
Step #1: Lay Out the Pieces
- The top edge of the sides (part C) are cut at a 22-degree angle to create the slope for attaching the oversized roof.
- To determine the angle of the cut, measure up 10-1/2" from one end and make a mark.
- From the same end, measure 9" up on the other side of the board and make another mark.
- Use a ruler or straight edge to draw a line to connect the marks. Cut along the line to create an angled side piece.
- The sides are shorter than the front section (part A). When aligned to the bottom edges and joined together, the shorter sides create a small gap under the roof line for air circulation and ventilation.
- Lay out and the drill the 1-1/2" entrance hole in the front (part A). Measure up 6" from the bottom edge, centering the entrance hole across the width of the front section. Use a Forstner bit, hole saw, or paddle bit to drill the entrance hole.
- Cut a 22-degree bevel across the top of the front section (part A) to match the slope of the roof and sides. Position the front section against one of the side pieces to test the fit. If the front piece is a bit too long, mark and cut the bottom of the front so that its bottom edge is flush with the bottom edges of the sides.
- Clip off each corner of the bottom section (part E) at a 45-degree angle, creating a gap for drainage gap.
Step #2: Assemble the Nest Box
- Attach the front (part A) to one side piece (part C) using weather-resistant screws or nails. This is the fixed side while the other side is hinged to allow access to the finished nest box for periodic cleaning.
- Attach the bottom (part E) to the sub-assembly.
- Line up the remaining side (part C) with the bottom of the front (part A).
- To create a hinge, secure the side section to the front assembly with one nail or screw driven into edge approximately 1-1/2" down from the top.
Step #3: Ensure Easy Access
- Position the partially assembled bluebird house box to the back (part B), leaving 1/2" space above the side pieces.
- Secure the back section to the fixed side piece with nails or screws.
- Then, create the hinged side by driving one nail or screw one through the back (part B) to form a pivot point. Position the hinge screws in the front and back sections directly across from each other, enabling the door to open easily (refer to the side view drawing). I used a small woodworking square to align the pivot points for hinge directly across each other.
- To keep the door closed, drill and countersink a screw hole along the center of the bottom edge of the pivoting side section. A single short screw will secure the door to the floor, yet removing the screw allows easy access for cleaning.
- Attach the oversized roof to the back and front sections. The large roof creates overhangs along the front and both sides to protect the nest box from rain.
- Drill a 1-1/2" hole through the center of the entrance guard (part F). Round over the edges with sandpaper, or use a round over bit to create a finished edge. Mount the entrance guard on a bias to create a diamond shape.
- Mount the finished bluebird nest box between 5' to 10' above the ground and facing out towards an open field or grassy area. Use the entrance hole to center and drive a mounting screw through the back section. I purchased a 6" long Philips head bit for my portable drill to reach through the entrance hole and drive a screw through the back piece and into a post or tree. Drive a second screw through the lower section of the back below the nesting box to secure the nest box.
Why Is the Size of Entrance Hole so Important?
The exact size of the entrance hole into the bluebird nest box is very important. The entrance hole must be large enough for the bluebird to enter, yet small enough to keep out the larger sparrows and starlings.
- Eastern Bluebirds fit comfortably through a 1-1/2" entrance hole.
- In areas with Mountain Bluebirds, increase the size of the entrance hole to 1-9/16" in diameter.
- Western Bluebirds will use either size, though some bird watchers report a higher success rate when using the 1-9/16" diameter entrance hole to the nesting box.
- Do not use nest boxes with a 1-5/8" entrance hole, which is large enough for starlings to enter.
Have you seen a Bluebird in your yard?
How Do I Attract Bluebirds to My Garden?
Bird watchers and gardeners try to attract bluebirds into their yards, both for their beauty and for the beneficial role they play in eating many different types of insects.
Bluebirds inhabit open spaces in rural areas, and they are often found near fields, pastures, and in open areas at the edge of woodlands. They can also be enticed to visit gardens that cater to their basic needs while providing an environment that makes them feel safe and secure.
Our garden strives to provide the four essential requirements for bluebirds and other feathered visitors: food, shelter, water, and nesting areas. Plants include a mixture of native and cultivated perennials and shrubs, planted along and under the mature oak trees where the birds can find berries and hunt for bugs.
What Do Bluebirds Eat?
Bluebirds eat grasshoppers, crickets, beetles, moths, and other insects
Bluebirds love eating mealworms, and this specialized feeder is equipped with entrance holes that are just the right size to let bluebirds in but keeps larger birds out. The bluebirds can eat in peace!
Fun Facts on Bluebirds
- There are three species of bluebirds in North America: the Eastern, the Western, and the Mountain Bluebirds.
- Bluebirds eat mostly bugs and berries, and they are typically not interested in bird feeders filled with birdseed.
- Bluebirds like mealworms and will visit feeders filled with live or freeze-dried mealworms.
- Eastern bluebirds can have up to three broods per season.
- Bluebird eggs are pale blue in color.
- In winter, several bluebirds will often roost together in a bluebird house for warmth.
- Bluebird populations suffered and declined in the 1960s but rebounded with help from concerned birdwatchers. The North American Bluebird Society was formed to encourage and instruct people to build and hang bluebird houses.
Baby Bluebird Hatching In A Nest Box
Peterson's Slant Front Bluebird House
This slant-front bluebird house is a bit more challenging to build than the basic nesting box, but the interesting design is worth the effort. Bluebirds like this nest box too, and they will readily move in to raise their brood. This article shows how I built this bluebird nest box, including diagrams, photos, and step-by-step instructions.
Folk Art Bluebird Houses
These birdhouses are built to the specifications preferred by the Eastern Bluebird. A bit of whimsy, a shaped entrance guard, a little paint, and a few repurposed items transform a basic nest box into an interesting piece of folk art that looks great in the garden.
Questions & Answers
What do you recommend for sealing the wood of the bluebird house?
I use oil-based stains and latex paint (thinned with water) to seal and color the exterior of many of my pine birdhouses. This helps to protect the wood from the elements. I also use tung oil to protect and bring out the grain of hardwoods including mahogany, walnut, and teak.
Sealing the wood isn't necessary, and I often leave the birdhouses unpainted to weather naturally. The wood quickly takes on a silvery-gray patina, and the birdhouse will last for several years.Helpful 4
What should I put in my birdhouse to help with nesting?
I do not place anything inside my birdhouses. I let the bluebirds gather the nesting materials themselves.Helpful 5
© 2011 Anthony Altorenna