How To Build And Install A Barn Owl Nest Box On A Tree: Complete Guide
Introduction
Barn owls are important to the healthy state of ecosystems because they regulate rodent populations. However, their populations are reducing due to habitat loss. Among the best ways for them to survive is by creating a safe nesting place. This underscores the importance of barn owl nest boxes, which resemble natural tree holes and are also an excellent space for breeding.
When constructing a nest box, it’s vital to highlight the necessity of a waterproof design to prevent nest material from absorbing moisture, protecting owl eggs and chicks from rainwater damage. Water cannot destroy the nesting material and subsequently damage the owl's eggs and chicks. The sloped bottoms, back-set entrances, and waterproof roofs will protect the inner part of the box from rain.

This guide outlines the main steps and materials needed to build a nest box.
Materials Needed
A barn owl nest box requires strong and durable materials to be around for years. Here is a list of the necessary items:
Plywood:
9mm exterior-grade plywood is recommended, ideally pressure-treated, to resist weather damage. This material provides the major part of the nest box, thus giving a good and warm space for the owls.
Batten Strips:
Batten strips are thin boards that are usually rectangular in shape. They may be used to strengthen a structure or as supporting members. For example, in the case of a barn owl nest box, they assist in reinforcing the frame where the plywood panels are to be installed.
You will require approximately 6 meters of batten wood, ideally pressure-treated, with recommended dimensions of 50x25mm.
Screws and Nails:
You will need about 100 screws of various sizes to keep the parts together. The nails may also provide additional strength to the structure.
Roofing Felt:
Roofing felt is used to shield the nest box from moisture and water since it has water-repellency properties. When it comes to a barn owl nest box, a water-resistant roofing felt preferably at size 62x57cm is recommended for covering the roof to provide a dry and safe environment for the owls.
Additional Tools
Here are some additional tools that you may use:
- Bevel for sharp angles.
- Weatherproof sealant for sealing joints.
- A nail gun or hammer is used to assemble the parts.
- A saw, measuring tape, and drill also ought to be recommended.
Key Design Features
A good barn owl nest box must fulfill the specific needs of barn owls and guard against various environmental problems. In this direction, the following are necessary design features:
Waterproof Structure
A deep entrance prevents the rain from entering the box. It should project over the edges for more cover. A sloped base helps any water that enters to drain away quickly and keeps the inside dry.
Ventilation and Drainage
Good ventilation prevents excessive heat and moisture from developing, making the place comfortable for the owls. Add gaps at the bottom for drainage to let out water, which helps lower the chance of dampness.
Entrance and Floor Depth
The nest box must have a minimum measurement of 450mm from the entrance hole to the floor of the nest box to protect the owl chicks. This depth ensures the young chicks do not fall out or climb out before they are mature enough to fly. It imitates the conditions of a natural nest, thus offering optimal conditions for their growth and development that help them avoid the dangers of exposure to predators or toxic substances before their maturity.
Inspection Panel
Adding on a readily removable panel makes the design easy to check and clean. This aids in checking the nest for condition and maintenance without disturbing the owls much.
Step-By-Step Nest Box Construction
Making a barn owl nest box requires careful measurements, strong assembly, and making sure it is waterproof. Follow these steps to build a nest box that will last and work well:
Cutting Plywood and Battens
- Measure and cut the plywood and batten strips to the proper sizes.
- You can find plans and diagrams on the Barn Owl Trust website.
- Ensure proper cutting to produce tightly fitted joints, which improve durability and stability.
Installing Support Battens
Put battens on the front and back panels. These battens serve to support the structure of the floor and inspection panel. Screw or nail them down hard to keep them in place.
Applying Sealant
Use weatherproof sealant on all batten seams. This step is very important to make sure the box stays waterproof. Let the sealant dry before proceeding with the assembly.

Assembling Sides and Floor
Begin by securing the side panels to the floor in a sequence of steps. The pieces must be tightly fixed with screws or nails so that there should be no space for water or wind to get inside the house. Finally, afterward, the sides are added to the structure and the top battens provide more rigidity to the structure. Hence, it shall not warp over some time.
Roof Waterproofing
Ensure that you have one of the roof widths, cut the roofing felt to the width you have, and place it over the top panel. Use a flexible weather-resistant compound around the perimeters to avoid water infiltration. Fix and nail or staple the felt so that it does not lose and come off when the weather becomes very bad. It is critical in this process to ensure that the interior does not get wet and to provide a dry nesting environment for barn owls.
Installing Hangers
The installation method depends on the tree design and other available resources. Here's how safely to install nest box hangers:
Choosing Installation Method
The selection of appropriate hangers is important for the secure attachment of the nest box on a tree. The decision will depend on the configuration of the tree trunk and available materials:
- Recycled Plastic Hangers: These are long-lasting, weather-resistant, and eco-friendly. They work perfectly for trees with irregular or curved trunks because plastic hangers can bend slightly to match the shape of the tree.
- Wooden Hangers: These are cheap and simple to make. They are ideal for straight or forked tree trunks, providing sound and secure anchorage.
Hanger Installation Steps
If you want to know how to install hangers on the back and bottom of the nest box, follow these steps:
- Rear panel holders
Attach hangers on the back panel at the top of the nest box.
Attach the hangers to the walls by using screws or nails and, for equilibrium, distribute the spacings evenly.
- Bottom hangers
If more stability is required, hangars or support brackets should be placed at the bottom of the box. These also help strengthen the nest box, especially if it is placed in an area with strong winds.
- Final Check
When lifting the box, check the hangers, ensuring that they are tight enough to carry the weight without shaking or moving.
Recommended Height and Position
The positioning of the nest box is as important as building it. Proper placement will, therefore, ensure the safety and usability of the box:
- Tree Fork Installation: Once the box is in the tree fork, it becomes stable with minimal wind movement.
- Therefore, the greatest height is 10-20 feet above the floor, with its contents out of the reach of animals trying to climb in but accessible by inspection.
- Entrance Orientation: Position the entrance away from prevailing winds and direct sunlight to make it comfortable and secure for owls inside.
Additional Considerations
Here are some extra considerations:
Using the Inspection Panel
Ensure the panel is tightly secured to prevent water seepage or disturbance during regular use. When it is not breeding season, open the panel to inspect the inside for any damage, debris, or wear. This feature keeps the nest box working but will not disturb owls too much.
Maintenance Tips
Regular maintenance will ensure the nest box remains longer and keeps a safe home for the owls.
- Check Waterproofing: After the rainy seasons, check the roof, joints, and sealant for any signs of leaks or wear.
- Reapply waterproofing if necessary: Inspect Structural Integrity Check the screws, hangers, and battens of the box for looseness or damage every year. Squeeze and replace parts appropriately.
- Clean the inside: Remove old nesting material and trash after each breeding season. This helps prevent the buildup of mold and pests.
Conclusion
Building and installing a barn owl nest box is a great project that enhances wildlife protection and improves local nature. If you follow the steps presented here and use good materials, you'll find a safe, weather-resistant, and long-lasting abode for these wonderful birds.
With regular maintenance, your nest box will continue to be a reliable shelter over many years. All efforts made to save barn owls also go toward restoring balance within the ecosystem they occupy.
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