• Back: 45cm x 15cm
• Base: 11cm x 15cm
• Front: 20cm x 15cm
• Roof: 21cm x 15cm
• Side panels: 11cm x 25cm high at the back and 20cm high at the front.

• 

Putting up a nest box

Robins use open-fronted nestboxes, and prefer them to be

low to the ground and concealed behind vegetation.

• Not too close to another nest box - nest boxes of the same type should not be sited too close together as this may promote aggressive behaviour between neighbours.
• Shelter your box from the weather - the front of the nest box should be angled vertically or slightly downwards to prevent rain from entering the nest box. Make sure it is sheltered from prevailing wind, rain and strong sunlight.
• Height from the ground should be 3 metres - small-hole boxes are best placed 1-3m above ground on tree trunks, but avoid sites where foliage obscures the entrance hole. If there are no trees in your garden, the next best option is to place your box on the side of a shed or wall. 
• Open-fronted nest boxes should be hidden from view - attach your box to a wall or fence that has shrubs and creepers growing against it. 

Great tits use small-hole nest boxes, and prefer them to be

1-3m above ground on tree trunks.

• Make sure cats cannot get into the box - ensure that it is not easily accessible to predators (cats and squirrels). 
• Consider a metal plate around hole to deter squirrels - this preventive measure that can be used to deter squirrels from gaining access. These plates are available commercially and can be purchased from any good garden centre or bird care company at very little cost.
• Keep nest box away from bird feeders - as high levels of activity of visiting birds could disturb nesting pairs.
• Use galvanized or stainless steel screws or nails that will not rust. If fixing boxes to trees, galvanised wire can be used to tie the box to the trunk or hang it from a branch. Make sure to regularly inspect these fittings to ensure the box remains securely attached.
• Traditionally, nest boxes for small birds are put up in the spring - pairs begin to prospect in the latter half of February, so a box put up at the end of the winter stands a good chance of attracting nesting birds. However, it is never too early or late to put up a nest box, as some birds will use them to roost in during the winter months.