All year round
Cut the timber for the bird box into six sections using the following measurements: back panel 45cm x 15cm; base 11cm x 15cm (with a few drilled holes for drainage); front 20cm x 15cm; roof 21cm x 15cm; and two side panels cut for a sloping roof, 25cm high on the back x 20cm high at the front.
Cut the wood along the pencil lines using a wood saw. Sand down all rough edges to protect the birds.
Nail one of the sides to the base of the bird box, then nail them both to the back section. Hammer gently to avoid splitting the wood.
Make sure you site your nesting box high up in a tree or building away from predators, strong sunlight and wind.
Turn the nesting box on to the fixed side and nail the other side into position. Three nails for each join should be enough.
Before fixing the front panel to the sides, make an entrance hole for the birds using a wide drill bit. Sand the edges smooth. A 25mm hole will attract blue, coal and marsh tits and a 28mm hole attracts great tits. House sparrows need a minimum hole diameter of 32mm to fit inside.
Place the bird box on its back and nail the front to the sides. The pieces should all fit together without gaps.
Use the self-tapping screws to fix the top to the sides and the front. This will allow you to remove the top to clean the bird box out.
Drill a hole in the top of the bird box and attach it to a tree using a screw. Position in a sheltered north-east facing spot.