Barred Owl Nesting Box Dimensions | Plans & Specs

Standard barred owl nesting boxes need a 12.25 x 12.25 inch floor, 23 inch interior height, and a 7 x 7 inch square entrance hole placed 12 inches above the floor.

For the full breakdown, see our best Barred Owl Nesting Box guide.

Building a nesting box that barred owls will actually use starts with precise dimensions. Get the floor size, entrance hole, or height wrong and the box sits empty. Get them right — along with the right materials and mounting — and you improve the odds of hosting a nesting pair through the season.

Interior Dimensions And Entrance Hole Placement

Barred owls require a box with a floor of 12.25 x 12.25 inches (12 x 12 inches is also acceptable) and an interior height of 23 inches from floor to ceiling. The square entrance hole must measure exactly 7 x 7 inches and sit 12 inches above the floor. Cut four 3/8 inch drainage holes in the bottom, and recess the floor board at least 1/4 inch up from the bottom edge to keep standing water out. A 2 inch front overhang above the entrance protects the opening from rain.

Place 3 to 4 inches of untreated wood chips in the bottom of the box. Some sources suggest 5 to 6 inches, but 3 to 4 is the most common recommendation. For those who prefer a pre-built option over cutting plywood, our roundup of the best barred owl nesting boxes on the market covers tested designs that meet these specs.

Best Materials And What To Avoid

Use 3/4 inch exterior-grade plywood, rough-cut cypress, or cedar for the box. All three resist rot without chemical treatment. Never use pressure-treated lumber, metal, plastic, or wood treated with creosote or pentachlorophenol — the chemicals can harm owls and their young. Leave the wood unpainted or apply a stain that contains no toxic preservatives. Drill ventilation holes near the top and drainage holes in the floor to keep the interior dry.

A common construction mistake is using the wrong material. Pressure-treated wood and plastic sheeting both trap moisture or leach chemicals, and neither provides the insulation and breathability barred owls need. The NestWatch barred owl box guidelines emphasize exterior-grade wood with no interior finishes.

Where To Mount The Box

Mount the box 12 to 15 feet above ground on a tree trunk in a wooded area. If placing the box above water, 6 to 8 feet above the water surface works. When mounting near water but on land, set it 30 to 100 feet from the edge at 10 to 20 feet high. In deeper woods, 20 to 30 feet up on a tree trunk is standard.

Position the box within 200 feet of water if possible. Make sure no branches or leaves block the entrance hole — obstructions give climbing predators access and reduce the owls’ visibility. Barred owls are territorial and need roughly 125 acres per pair, so space boxes at least half a mile apart. Placing them closer than that nearly guarantees conflict or abandonment.

Nesting season for barred owls runs from December through June in Florida. Install the box before December so owls have time to find it before laying eggs.