Nest box positioning and preparation
Site nest boxes so that they are sheltered from the wind, rain and strong sunlight, ie facing between North and East. This will prevent the chicks dying from overheating in summer and offer shelter from wet and cold winds in winter.
Position boxes between 1.5m and 5m above ground for safety from predators and to replicate natural nesting habits. This height also helps to ensure that the birds have a clear flight path to the nest without obstacles usually found at lower levels.
Choosing the right area
Avoid putting up boxes in busy areas of the garden, such as near a bird table or feeders. Robins and Wrens in particular look for nesting sites in good cover, well hidden in vegetation at a relatively low height, usually below 2m.
It is important that the chicks have somewhere to perch when they first leave the nest, so try to position the box near some smaller branches that will not hold the weight of larger predators, but will support fledglings.
The best time to put nest boxes up is outside the breeding season, between August and February.
Essential box features
Check that any box you buy is dry and has small drainage holes at the bottom. If it has a lid, make sure it's secure so that magpies and squirrels can not raid the nest. All National Trust boxes are guaranteed to comply with these standards.
If you are fixing your box to a tree try not to damage the trunk. Ideally, secure it with a strap.
House martin nest bowls should be situated under the eaves of a house. As house martins often return to the same nesting sites, you're more likely to attract them to your nesting site if they already nest nearby.
Do not line the box, birds will do this themselves. You can leave pet hair or your own hair out in spring for them to collect. Do not leave out knitting wool or man-made fibres as these can be dangerous.