Bird boxes can be designed to be discrete or showpiece design elements but either way they can transform your garden into a haven for our feathered friends. Moving past the traditional hole-in-a-box approach puts us in a fascinating world of shapes, materials and colours to cater for all sorts of species of bird. By carefully choosing your birdbox, you can significantly affect the popularity and therefore, occupancy rates.
Making your own bird box designs
A bird box can be an entry level carpentry project for several reasons; they can be relatively simple, birds aren’t too picky about the odd mistake and if you need to start over, there’s not much wastage.
Another advantage of making your own is you get to decide on all aspects of the design in terms of functionality and aesthetics. You may want to attract a specific species or to blend the box into a particular area.
Material choice is important and the vast majority of bird boxes are made of wood but if you decide to go with another material, ensure it is up to the task. The main function of a bird box is shelter, so it has to be obviously waterproof but you also need to make sure that the material you choose insulates from excessive temperatures both hot and cold. 15-20mm (0.6-0.8inch) thick wood is ideal for this, any substitute material should have similar thermal properties or have measures to increase insulation.’
For example, metal would be a perfect material for protection and durability but is a very good conductor so it’s a very poor insulator. To mitigate this, a metal bird box should be installed well away from direct sunlight and insulated inside using a suitable material.
Bird boxes are normally fairly simple designs but if you are taking on a more complex structure or simply want to do the best job possible, try our cutlist generator.
How big should the hole be in a bird box?
This depends on the type of bird that you want to attract. Generally, birds don’t carry accurate measuring devices so the following table is just a guide but are the hole sizes the different common species seem to prefer along with a few other dimensions. Small birds like finches, tits and sparrows prefer small holes of around 25-28mm whereas robins prefer a small shelf.
| Species | Floor cm (in) | Height cm (in) | Hole diameter cm (in) | Hole above floor cm (in) | Box above ground m (ft) |
|---|---|---|---|---|---|
| Barn owl | 15×15 (6×6) nesting shelf | 15 (6) | – | – | 2.5-3.5 (8-12) |
| Robin | 18×20 (7×8) nesting shelf | 20 (8) | – | – | 2-4.5 (6-15) |
| Wren | 10×10 (4×4) | 15-20 (6-8) | 2.2 (0.9) | 10-15 (4-6) | 2-3 (5-10) |
| Bullfinch | 10×10 (4×4) | 15-25 (6-10) | 2.5 (1) | 10-20 (4-8) | 2-4.5 (6-15) |
| Sparrow | 12×12 (5×5) | 18-30 (7-12) | 2.8 (1.1) | 10-20 (4-8) | 2-4.5 (6-15) |
| Green woodpecker | 15×15 (6×6) | 30-45 (12-18) | 5.0 (2) | 20-30 (8-12) | 3-4.5 (10-15) |
| Goldfinch | 10×10 (4×4) | 15-25 (6-10) | 2.5 (1) | 10-20 (4-8) | 2-4.5 (6-15) |
| Starling | 15×15 (6×6) | 45-60 (18-24) | 5.0 (2) | 25-40 (10-15) | 4-6 (12-18) |
| Goldcrest | 10×10 (4×4) | 15-20 (6-8) | 2.5 (1) | 5-10 (2-4) | 2-3 (5-10) |
Remember to put a few smaller holes in the base for drainage and ventilation and perhaps a couple more in the sides in hot climates for further ventilation.
When is the best time to put up a bird box?
You can put your bird box up at any time because the local population will notice it and seek it out when they need it. However, they are actively looking for candidate sites around mid to late winter so if you get yours up around then, you have the optimal chance it’ll get occupied.
Where should you put a bird box?
Most birds normally nest in trees so the best place for a bird box is in a tree too. Make sure the place you choose is well sheltered and refer to our sizing guide for help on how high different species of birds prefer their nests.
Which way should a bird box face?
Somewhere between North and East will offer some protection from the weather, also tilting the box slightly forward will prevent the worst of the rain from getting in. The direction to avoid is South, the direct sunlight that the box would be exposed to would potentially harm the chicks or eggs due to over heating.
