This guide to making your own DIY bird box is not only a fun project for you, it also provides a safe place for cavity-nesting birds to raise their young.
11.07.2023
In many urban areas, there is a limited amount of natural habitat suitable for birds to breed in undisturbed. Making a bird box is one way that anyone with a garden, balcony or allotment can help by giving birds a place to nest and lay eggs. Birdhouses and nesting boxes for birds are popular and simple DIY projects that are usually made from wood, to provide shelter from wind and weather and protect against predators who could steal eggs from the nest. You can find plans for building various birdhouse designs online; our design idea transforms an old log.
The Royal Society for the Protection of Birds (RSPB) recommends minimum floor space of 10 cm by 10 cm and a height of 20–25 cm. However, you also need to consider the size of its entrance hole, as this generally determines which bird species takes up residence. Small bird species will choose small entrance holes to prevent larger birds and predators from getting in. This means that if you have enough space, you may be able to support a range of bird species by making bird boxes with entry holes in various sizes. Think about what birds you have in your area and which you would like to attract to your bird box.
Blue tits and marsh tits prefer a bird box with an entrance hole around 25 mm wide, while great tits need a slightly larger entry of 28 mm.
Wagtails and spotted flycatchers prefer birdhouses that are semi-open at the front, as do blackbirds and robins.
Little sparrows are different from most hole-dwelling bird species because they love to be sociable. For most species, only a single bird box in an area will be inhabited, but if you are making a sparrow box, it’s a good idea to consider designing it for multiple nests or installing several in a group.
The entrance hole depends on the size of the bird species that you hope to move into the bird box. The RSPB recommends the following sizes:
All you need to get building our beautiful DIY bird box is a piece of log, a STIHL chainsaw, a drill, a sawhorse and a free afternoon. Once you have decided on which bird species you want to attract, take note of the size you need your entrance hole to be. Now you can start building a perfect haven for local birds.
Oak, robinia and larch are ideal for long-term outdoor use as they are highly durable. Pine and spruce are also possible alternatives. It’s essential that you use untreated wood to build your birdhouse, as wood preservatives and varnishes give off fumes that could scare off birds and even put their health at risk.
If you want to protect the wood from moisture and fungal attack, linseed oil is suitable for treating the exterior. However, because the bird boxes are hung outside, they will dry of their own accord after wet weather, which means that untreated wood boxes last several years.
Using a chainsaw for the bird box means you can get the job done quickly, but always make sure you are wearing personal protective equipment when working with your chainsaw. This includes cut protection trousers, safety boots, safety glasses, a face shield, gloves, a helmet if there is a risk of falling objects and ear protection. You don't need to wear ear protection with most of our cordless chainsaws but the instruction manual for your product contains more details on this. Fully familiarise yourself with the tool before you use your chainsaw for the first time, and check it is in flawless condition before each use. On request, your STIHL dealer will be happy to prepare your tool for its first use, and will also advise you on models and sizes of protective clothing that you can try at your leisure. Please remember that personal protective equipment is no substitute for safe working techniques.
Once all the preparations are in place you can get started on making your bird box. Check your surroundings and make sure you have enough room in your working area to avoid tripping and other hazards.
The first step is to saw a thick slice (approximately 3cm) from the trunk by making a vertical, straight separating cut; this will be the base of your bird box.
Secure the trunk on the sawhorse. Use the saw to first make two parallel cuts to a depth of approximately 20 cm on the left and right sides. Rotate the trunk through 90° and make two more cuts to create a square.
Caution: This method of working has an increased risk of kickback. Be certain to observe the safety information in the operating instructions.
Create the main chamber from the end of the trunk you have just cut into, using an angled cut across that will make the pitched roof of your birdhouse. You can now finish hollowing the piece of wood by knocking out the centre.
The next step is making a way in. The easiest way is to use a drill with a hole saw bit, or a jigsaw. Check the diameter you need for the birds you hope to attract.
Saw a roof slab from the discarded part of the log, cutting a “plank” from the centre with two parallel strokes. Remember that the roof needs to be longer than the diameter of the wood, because it will be fixed at an angle (in our example the total size is approximately 30 cm).
First use eyebolts to attach the base to the main house, then the roof can be nailed on. Make sure that the roof extends beyond the bird box walls so that rain can run off without any problems.
Using eyebolts instead of nails means it will be easy to open your bird box for cleaning after the birds have moved out at the end of the season. Old nests will not be reused, so you should clean it out to make sure the bird box is as healthy as possible for your garden birds.
Making a DIY nesting box is only half the job: you also need to take care when it’s time to put it in place. It’s important to follow these instructions so that resident birds and their offspring are sufficiently protected against predators, weather conditions and people: