DIMENSIONS

The ideal dimensions for a Barn Owl box should be as follows:
1. Floor dimensions should be 600mm x 400mm.
2. Front wall = height 400mm x length 600mm.
3. Back wall = height 500mm x length 600mm. (the side to be attached to tree / house /barn)
4. Side walls x 2 = height 500mm and 400mm x width 400mm.
5. One side has entrance 100mm to 120mm square, located centre of side.
6. One hinged lid for the roof  800mm x 500mm, with a waterproof lining to keep out rain water.
7. Perch 150mm x 100mm just below this entrance hole is essential outside the box for the owls to land on when they arrive backat the box.

Note:
The Spotted Eagle Owls breeding box is slightly smaller in dimension asthey tend  to have smaller clutches of young.
Floor dimensions are 400mm x 400mm the other dimensions can be scaled down proportionately but keep the heights of the front / back and side panels the same.

MATERIALS

Pine is probably the answer for this project as the timber is easily available and not that costly. Any harder timber is cost prohibitive and more difficult to work with. Chipboard based material is not suitable for this project as it will not withstand the elements.
The exterior of the box can be treated with a polyurethane sealer to protect the timber against the elements.
Use brass hinges for the roof lid and say 250micron plastic underlay for roof lining or acrylic waterproofing compound to make it watertight.

METHOD

Start by making a frame using 38mm x 38mm pine batten as per given dimmesions.
The frame will make the structure rigid and more durable.
Once the frame is constructed you can use pine slats 100mm to120mm x20mm or suitable pine ply wood for the sides / floor cladding.
For the roof lid it would probably be the easiest to use a solid panel of pine ply 800mm x 500mm which can be underlayed with the plastic waterproofing membrane or simply coat the top of the panel with anacrylic waterproofing compound.

POSITIONING

1. The larger side of the box should be attached to a tree, your house, or any other suitable structure on your property.
2. Position box at least four or five meters from ground level. Yous hould be able to access the box in order to re locate young if they fall out of the box..
3. It is best to position the box where there is not too much vehicle or human traffic.
4. Owls favour north. facing entrances.
5. Spotted Eagle Owls like nesting in exposed positions, where they cankeep a watchful eye over surroundings. The opening for this box must bel ike a stable door where the bottom door section is closed and the top section missing. Position it same as the standard box.