How to Build an Owl House | Plans, Dimensions, and Setup Tips

Building an owl house means constructing a large, untreated wooden nest box with a 3–6 inch entrance hole, drainage, and a hinged access door, then mounting it 10–30 feet high facing South or East near good hunting habitat.

Putting up an owl box is one of the most effective ways to invite natural pest control into your yard. A single family of Barn Owls can eat thousands of rodents a year, and the right nest box will get them to move in fast. This guide covers the exact dimensions for Screech, Barred, and Barn Owls, the correct wood to use, how to assemble the box, and where to mount it so the owls actually stay.

Which Owl Species Are You Building For?

Your measurements change depending on the species you want to attract. A Screech Owl needs a much smaller entrance than a Barn Owl, and the box depth varies significantly. Build for the species common in your area — Eastern Screech Owls live across the eastern half of the US, Barred Owls are nationwide in woodlands, and Barn Owls favor open fields and farmland nearly everywhere.

The table below shows the three most common plans, so you can pick the one that fits your yard.

Wood Selection: What Works and What Doesn’t

Use untreated wood only. Treated lumber contains chemicals that are toxic to birds and their eggs. Eastern White Cedar, Red Cedar, pine, and redwood are all good choices. The wood needs to be at least ¾ inch thick to insulate the interior against summer heat and winter cold — thinner wood makes the interior temperature swing too fast for eggs and chicks.

Skip exterior-grade plywood if you can: it delaminates after a few rainy seasons. Solid wood boards last longer and hold screws better. Northern Woodlands’ long-running guide uses standard pine from any lumber yard and reports boxes lasting a decade or more with basic maintenance.

Key Specifications for the Box Itself

Beyond wood type and rough dimensions, a few design details separate a box that gets used from one that stays empty.

• Entrance placement: For a Screech Owl, the bottom of the 3-inch entrance hole should sit 10 inches above the interior floor. For Barn Owls, the square entrance can be centered or offset — the Barn Owl Trust puts it about 6–8 inches from the top of the front panel.
• Kerf cuts (talon grooves): Cut four to five shallow grooves (⅛ to ¼ inch deep, about ½ inch apart) on the exterior below the entrance. Owls use these to grip the wood when landing — smooth wood is slippery for them.
• Recessed floor: Set the floor board ½ inch above the bottom edge of the side panels. That recess prevents rain water from wicking up into the nesting area through capillary action.
• Drain holes: Drill four ¼-inch holes in the floor board. Spare water needs an escape route even with the best roof overhang.
• No exterior perch: Northern Woodlands explicitly warns against it — a perch outside the hole gives predators like raccoons a grip point. Owls don’t need it; they land on the opening edge and enter.
• Flat interior perch: Some builders add a 2-inch-wide ledge or a short strip of wood 2 inches below the inside of the entrance hole. It gives owlets a spot to rest at the opening before fledging.

Step-by-Step Assembly

These steps follow the Audubon guide for a Screech Owl box, but the process is nearly identical for Barred and Barn Owl boxes — only the piece sizes change.

1. Cut the pieces: Using your chosen plan, cut the back, front, two sides, floor, and roof from ¾-inch untreated wood. Cut the entrance hole in the front piece before assembling — it’s easier to drill or jigsaw on a flat board.
2. Add the kerf cuts: On the exterior of the front piece below the entrance hole, make four parallel cuts about ¼ inch deep and ½ inch apart. Use a circular saw or router for consistent depth.
3. Drill drainage: Drill four ¼-inch holes in the floor piece. Mark the ½-inch recess height on the side pieces so the floor sits above the bottom edge when assembled.
4. Screw the sides to the back: Pre-drill all screw holes to prevent splitting. Use exterior-grade screws (deck screws work well). Attach the left and right side panels to the back panel.
5. Install the floor: Position the floor at the recessed height and screw it into the sides from below. The recessed floor leaves a small gap at the very bottom of the box — that gap is intentional for drainage and air movement.
6. Attach the front panel: Screw the front piece to the sides. Align the top edges so the roof sits flush later.
7. Hinge the roof: Position the roof so it overhangs the front and sides by about an inch. Attach two exterior hinges to the roof and the back panel — this creates the access door for cleaning. Add a locking latch on the front edge so the roof stays shut against wind and predators.
8. Add nesting material: Put 2–3 inches of wood chips, dry leaves, or untreated pine shavings in the bottom before mounting. Don’t use cedar shavings — the aromatic oils can irritate young birds.

If you’d rather skip the tool work, our roundup of tested pre-built boxes shows models that match these exact specs. See the best owl houses ready to mount — every one on that list uses untreated wood, proper dimensions, and predator-safe designs.

Mounting the Box Correctly

Even a well-built box fails if it’s in the wrong spot. Owls are sensitive to disturbance and need a clear approach path.

• Height: Mount the box 10–30 feet above ground (Screech and Barred Owls). For Barn Owls, 12–15 feet is the minimum — higher is better if available. IN.gov’s DNR guide recommends the 12–15 foot range for Barn Owls specifically.
• Orientation: Face the entrance hole South or East. That orientation catches morning sun and shelters the opening from prevailing north winds. Avoid facing North if you can.
• Mounting surface: A live tree wider than the box works well — the trunk provides natural insulation on the back. A pole-mounted box in a field is even better for Barn Owls. If using a tree, remove only the branches that block the flight path; keep nearby branches the owls can land on before entering.
• Distance from human activity: Place the box at least 65–100 feet from houses, sheds, or paths. Closer placement risks the female abandoning the nest during incubation.
• Multiple boxes: If you’re putting up several, space them more than 100 feet apart. Owls are territorial, and boxes too close together may only attract one pair.

Final Setup Checklist

Before you call it done, run through this short confirmation list.

• Untreated ¾-inch wood — no treated lumber anywhere.
• Recessed floor ½ inch above bottom edge with ¼-inch drain holes.
• Kerf cuts below entrance on the outside front.
• No exterior perch attached below the entrance.
• 2–3 inches of untreated wood chips or dry leaves in the bottom.
• Hinged roof with a locking latch (for annual cleaning access).
• Box mounted 10+ feet high facing South or East with a clear flight path.
• No rodenticide or pesticide use in the immediate area.
• Annual cleaning schedule: empty old nesting material and rinse with hot water after each nesting season ends (typically late summer).