How to build a nestbox

Learn how to build a simple bird nest box with step-by-step instructions. Help local wildlife, support biodiversity, and give native birds a safe place to nest with this rewarding DIY Guardian project.

WILDLIFE GUARDIANS BEGINNER GUARDIAN

keeper of the light

7/4/20262 min read

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How to Build a Simple Bird Nest Box

Building a bird nest box is one of the easiest and most rewarding ways to help local wildlife. In just a couple of hours, you can create a safe place for birds to nest and raise their young.

What You'll Need

Untreated timber (15–20 mm thick)
Saw
Drill
25 mm or 32 mm hole saw (depending on species)
Screws or nails
Screwdriver or hammer
Measuring tape
Sandpaper

Avoid: Treated wood, plywood, MDF, or painted timber.

Step 1 – Cut the Wood

Cut the following pieces:

Front: 150 × 250 mm
Back: 150 × 300 mm
Two sides: 120 × 250 mm
Base: 120 × 120 mm
Roof: 180 × 180 mm

The longer back panel allows the box to be fixed securely to a tree or wall.

Step 2 – Drill the Entrance Hole

Choose the entrance hole size for the birds you want to attract:

25 mm – Blue Tits, Coal Tits, Marsh Tits
28 mm – Great Tits, Tree Sparrows
32 mm – House Sparrows, Nuthatches

Drill the hole approximately 50 mm below the roof.

Do not add a perch. Birds don't need one, and it can make it easier for predators to access the nest.

Step 3 – Assemble the Box

Attach the two side panels to the back.

Fit the base between the sides.

Attach the front panel.

Finally, fix the roof so it slightly overhangs the front to keep rain out.

Use exterior screws if possible.

Step 4 – Add Drainage

Drill a few small holes in the base.

These allow water to drain away and keep the nest dry.

Step 5 – Add Ventilation

Drill two or three small holes near the top of each side panel.

Fresh air helps prevent overheating during warm weather.

Step 6 – Position the Nest Box

Mount the box:

2–4 metres above the ground
Facing between north and east
Away from strong sunlight and prevailing rain
In a quiet location

Avoid placing boxes close to bird feeders during nesting season.

Step 7 – Leave Nature to Do the Rest

Resist the temptation to check inside while birds are nesting.

Watch from a distance and enjoy seeing wildlife thrive.

Annual Maintenance

Each autumn, after the breeding season has finished:

Remove old nesting material.
Brush out the inside with hot water (avoid chemicals).
Check that the box remains secure.
Replace damaged parts if necessary.

A well-built nest box can provide a safe home for birds for many years.

Guardian Tip 🌱

Building a bird box isn't just a woodworking project—it's a simple act of stewardship. One afternoon of effort could provide a home for countless generations of birds and help strengthen biodiversity in your local area.

Small action. Lasting impact.