Boxes are made from 18mm slow-grown pine from a responsible source and supplier. The front joints are dove-tailed to provide a more secure and longer lasting joint and all joints are glued on assembly.
The box roof is pitched to deter other birds and predators from perching on the box. The roof and overhangs the box totally to ensure that no rain enters the box. There is a rain drip rebate cut into the box lid to prevent water ingress into the box. The long roof overhang at the front is to prevent rain from entering through the entrance hole as much as possible. The roof is hinged at the back, so that the box can be cleaned at the end of the season and is held shut by a hook and eye.