Owl House Plans

Owl House Plans at a Glance

Most owl house builds fail before the first owl looks at them. Wrong entrance hole diameter. A perch rod that invites raccoons. No cleanout door. This guide gives you the right dimensions for the species you actually have in your area, a complete cut list, and the design details that separate a functional nest box from a decorative one.

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In this guide:

• Pick your species — hole size is not interchangeable
• Cut list and materials for the screech owl box
• Build the box, step by step
• Mount it correctly, guard it against predators

How to Use This Guide

Two species cover 90% of backyard builds in the US: the Eastern Screech-Owl and the Barn Owl. Their boxes are not interchangeable. Read Part 1 before you buy lumber. Building the wrong box wastes an afternoon and money.

If you already know your species, jump to Part 2 for the cut list.

Part 1: Pick Your Species

The entrance hole diameter is the most important dimension in an owl house. Too small, the owl can't enter. Too large, and you've built a predator handhold.

Eastern Screech-Owl

Build this box if you live in a suburban neighborhood, rural edge, or anywhere with mature trees. According to Cornell Lab's All About Birds, the Eastern Screech-Owl is one of the most box-receptive owls in North America. It nests in city parks, farmland, and forest edges. Anywhere humans live that has a few large trees. It's 8-10 inches long, about the size of a robin. Get the dimensions right and it will use a box in your yard.

The 3-inch entrance hole excludes European Starlings and squirrels while fitting the screech owl's body profile. It also limits how far a raccoon arm can reach into the box. It doesn't eliminate the risk, but it reduces it.

Barn Owl

Build this box if you're on rural farmland with open grassland. The Barn Owl Box Company recommends at least 5-10 acres of open hunting territory within range of the box. Without that habitat, the box sits empty regardless of construction quality. Barn owl boxes are significantly larger. The interior floor is 17" × 17", the entrance hole is 6", and the box typically mounts 12-18 feet up on a pole at a field edge or the exterior of a barn.

A 6-inch hole is large enough for a raccoon arm to reach through. A predator guard is not optional for barn owl boxes.

Barred Owl

Build this if you're in mature eastern deciduous forest, ideally near water. Barred owls are the hardest of the three to attract. They're not suburban birds. Their entrance hole is 6" wide by 7" tall with an arched top. The build process is the same as a screech owl box scaled up.

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Species specifications

The rest of this guide focuses on the screech owl box. It's the most common build, most achievable for a suburban backyard, and the plan most likely to result in an occupied box.

Part 2: Cut List and Materials

Choose your lumber

Cedar is the right call if you want the box to last. Its natural oils resist rot and insects without any finish, and it weathers well in rain and sun. Plan for $25-35 in lumber for one screech owl box.

Untreated pine (1×10 or 1×12) is what Cornell NestWatch and the Audubon Society both specify in their official plans. It works well, costs less ($15-20 in lumber), and is available at any home center.

Whichever you choose: untreated, 3/4" minimum thickness, no pressure-treated stock. Pressure-treated lumber off-gasses VOCs (volatile organic compounds from the chemical preservatives) inside an enclosed cavity. Toxic to nesting birds and a guarantee the box stays empty.

Do not use cedar shavings as interior bedding. Cedar boards for the box exterior are fine. Cedar shavings inside emit aromatic oils that irritate birds' respiratory systems.

Screech owl cut list

Everything cuts from one 10-foot 1×10 board. Actual board width is 9.25 inches.

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Each side has an angled top cut: 18" tall at the back, 15" tall at the front. This creates the slope that sheds rain off the roof. Mark both sides together and cut them as a pair. The floor gets ripped to 7.75" wide so it fits between the two 3/4"-thick side walls inside an 8" × 8" cavity.

These dimensions are based on the American Eagle Foundation's nest box plans, which are derived from the Cornell NestWatch standard.

Hardware

• 24 exterior wood screws, 1-5/8" or 2"
• 2 brass hinges (for hinged roof cleanout door)
• 2 galvanized lag screws, 1/4" × 4" (for mounting to tree or post)
• 1 hole saw, 3" diameter (or a jigsaw with a 3/4" pilot hole to start)

Tools

• Circular saw or miter saw
• Drill/driver
• 1/4" and 1/2" drill bits
• 3" hole saw
• Chisel (for scoring interior below entrance)

Part 3: Build the Box

These steps are in order. Don't skip the scoring step in Step 4. Most builds do. Most box failures trace back to it.

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Step 1: Cut all pieces and label them

Cut the back, front, two sides, floor, and roof from your board. Label each piece with a pencil before moving on. The sides look nearly identical. Labeling prevents backwards assembly.

Step 2: Drill drainage holes in the floor

Six to eight 1/4"-diameter holes, evenly spaced across the floor piece. Rain enters through the entrance hole. Without drainage, water pools on the floor and kills chicks. Keep the holes small enough not to create drafts.

Mark a reference line on each wall piece at 1/2" up from the bottom edge. The floor mounts at this line during assembly.

Step 3: Drill ventilation holes in the sides

Two 1/2"-diameter holes in each side piece, 1 inch from the top edge. Four total. Temperatures inside a sealed cavity can spike in summer heat. According to the Tennessee Wildlife Resources Agency, adequate ventilation is essential to prevent overheating that kills eggs and chicks. Position these holes high, where heat accumulates, not near the floor where they'd create drafts through the nest.

Step 4: Drill and prepare the entrance hole

Mark the entrance center on the front piece: horizontally centered, 11 inches up from the bottom edge. Drill a 3/4" pilot hole, then use a 3" hole saw. Clean up the cut with sandpaper or a file.

Now score the interior face of the front board below the hole. Use a chisel to cut 4-5 horizontal grooves between the hole and the bottom of the board, spaced about 1 inch apart, 1/16" to 1/8" deep. Owlets climb to the entrance when they're ready to fledge. They do it by gripping with their talons. Smooth wood is unclimbable. Skip this step and the owlets can't reach the exit.

Step 5: Assemble the box

Lay the back piece flat on your bench. Predrill and attach the two side pieces to the back with exterior screws, two per joint. Keep the angled tops aligned.

Place the floor piece inside the box with its bottom face at the 1/2" reference line. Predrill through the side walls into the floor edges and screw in place.

Align the front piece with the angled tops of the side pieces. Predrill and attach with two screws per side.

Step 6: Attach the roof

Mount the two brass hinges to the rear edge of the roof, then to the back wall. The roof should overhang the front by 1 to 1.5 inches to shed rain away from the entrance. Confirm the roof opens fully. You need that access to clean the box each fall.

Step 7: Add bedding

Pour 2-3 inches of untreated pine shavings onto the floor. Owls don't build nests. Without bedding, eggs roll on bare wood and get damaged. Pine shavings insulate the eggs and give the cavity the texture of a natural tree hollow.

The design decisions behind this box

Each non-obvious feature has a specific reason. Here's the logic:

No external perch. Owls fly directly into their cavity. They don't use perches. An external perch is a foothold for raccoons reaching in for eggs. Leave it off every time.

Recessed floor. The floor sits 1/2" above the bottom edge of the walls. Rain that wicks up through end-grain wood joints stops at the gap rather than reaching the nest floor.

Hinged roof cleanout. A box that can't be cleaned fills with parasites (blowfly larvae, mites, lice) and old material. Owls won't return to an infested box. Open and clean it each September after the nesting season.

Scored interior below entrance. Covered in Step 4. Most skipped step in owl box builds.

No paint on the interior. Natural wood only inside the box. Chemical finishes off-gas in enclosed cavities. On the exterior, a water-based stain is acceptable once fully cured.

Ventilation holes near the top. Position them high on the side walls, where hot air accumulates. Holes at the bottom create drafts through the nest.

Part 4: Mount and Protect It

Predator guards

Raccoons will find the box. A guard on the mounting pole is more reliable than any modification to the box itself.

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Stovepipe baffle (best option): 8-inch diameter aluminum stovepipe, 24 inches long, on the mounting pole below the box. NestWatch research found stovepipe baffles significantly increased nest success compared to unguarded boxes. This design deters raccoons and rat snakes. The baffle must not touch the ground. No branch or surface should bridge past it. Cost: about $25 in materials from a heating supply store.

Conical baffle: A cone at least 3 feet in diameter attached below the box. Easier to build or buy. Less effective against determined raccoons than the stovepipe design but worth using if the stovepipe isn't practical.

Entrance hole extender: A 3-4" wooden cylinder over the entrance hole, extending outward. It reduces how far a raccoon arm can reach inside. Drill a matching 3" hole through a 3-4" length of 2×4 or similar stock and attach it over the entrance during assembly.

For a detailed comparison of baffle types, sialis.org's baffle guide documents which guards perform against snakes, raccoons, and squirrels respectively.

Mounting

Screech owl:

• Height: 10-15 feet
• Surface: medium-to-large tree trunk or post, in partial shade
• Orientation: face east, northeast, or southeast. Easterly-facing boxes warm with the morning sun after cool nights and stay cooler in the afternoon. Avoid south-facing in hot climates.
• Attach with two 1/4" × 4" galvanized lag screws through the back panel

Barn owl:

• Height: 12-18 feet on a metal pole (metal preferred; wooden posts attract competing species)
• Habitat: open grassland or agricultural fields within a quarter mile for hunting territory
• The box alone won't attract barn owls without suitable habitat nearby

Timing

Install by late January or early February. Screech owls begin scouting nest sites in February and claim them before egg-laying starts in March-April. A box installed in April may go unnoticed until the following year.

Many boxes sit empty for one or two full years before occupancy. That's normal. Cornell Lab documents that screech owls explore potential sites across multiple seasons before committing. A maintained box has a better chance each successive year.

Where This Fits

Skills required: crosscut lumber accurately, drill, drive screws. A circular saw or miter saw and a drill are the only power tools needed. Joinery is entirely butt joints.

What comes next: The same skills and most of the same dimensions apply to a wood duck box (6" entrance hole, 12"×12" floor, 24" depth) and an American Kestrel box (3" hole, 8"×8" floor; identical screech owl dimensions, different habitat requirements).

What you built: A functional wildlife structure that serves the same purpose as a natural tree hollow. It gives a cavity-nesting species a home in a landscape where old-growth trees are increasingly scarce.

Sources

Published plans and field research from wildlife agencies and ornithological organizations informed this guide.

• NestWatch Cornell Lab — Eastern Screech-Owl — official screech owl box dimensions and specifications
• Audubon Society — How to Build a Screech-Owl Nest Box — assembly instructions and material recommendations
• American Eagle Foundation — Nest Box Plans PDF — dimensional diagram with cut layout
• NestWatch — Predator Guards Carry Their Weight — research data on baffle effectiveness
• NestWatch — Dealing with Predators — predator guard types and placement
• sialis.org — Baffles for Nestboxes — stovepipe vs. cone comparison
• Tennessee TWRA — Screech Owl Nest Box — state wildlife agency specifications
• Tennessee TWRA — Barn Owl Nest Box — barn owl specifications
• Barn Owl Box Company — Installation — barn owl mounting guidance and habitat requirements
• Indiana DNR — Barn Owl Nest Box Building Guide — step-by-step barn owl box with photos
• 70birds.com — Barred Owl House — barred owl dimensions
• Cornell Lab All About Birds — Eastern Screech-Owl — life history and nesting biology