Bird houses size guide

Bird houses can have a tremendous impact on the breeding and survival rates of garden birds in your area.

So find out what nesting box best suits your favourite bird in need.

Nest boxes are also a great way to get birds visiting your garden regularly. With roosting residents you’ll have regular feathered guests at your table. And if your lucky you can share the joys of parenthood as the little fledglings take their first flutters and eventually fly the nest.

When setting up or purchasing bird houses, there are a few key choices to keep in mind:

Who lives in a house like this?

There a lots of bird species that are known to use a bird house including:

Blue, great and coal tits
Nuthatches
House and tree sparrows
Starlings
Spotted and pied flycatchers
Robins
House martins

However, not all birds are looking for the same thing in a potential home. A lot rests on the differences in size and type of bird house. These factors will vary in importance for the different species.

The choice is yours

Another thing to remember is that some birds are in need of housing help more than others. For example, the RSPB has noted the recent increase in numbers of great tits and the dwindling number of sparrows. So when you are choosing or making a nest box, the choices you make will affect which birds will potentially use it. You can therefore make decisions that can positively benefit struggling species.

Bird house hole size

The size of the whole will determine who can move in. The RSPB advises the following dimensions for some of the different species:

25 mm for blue, coal and marsh tits
28 mm for great tits, tree sparrows and pied flycatchers
32 mm for house sparrows and nuthatches
45 mm for starlings

In all cases, the bottom of the entrance hole must be at least 125mm from the floor of the bird house to stop small chicks from falling out or naughty cat’s paws coming in.

They should be placed 2-4m above the ground up a tree or on a wall. To avoid too much direct sunlight and wet winds, have the box front face between somewhere between north and east.

By tilting the box forward a little you can encourage any rainwater to drain out and always make sure there is a clear flight path in front of the bird house for easy access.

Open fronted boxes

In addition to the common bird house design with a small hole on the front, there are other boxes that have an open front with a small panel at the base, which appeal to other birds.

The RSPB advises different sizes for the front panel for different species as follows:

100mm high open front for robins or pied wagtails
140mm high front panel for wrens
60mm low front to the box for spotted flycatchers

These open-fronted boxes also need to be sited at different heights from the ground for the birds concerned:

Less than 2m from the ground and hidden in vegetation – Robins and wrens
2-4m high up, sheltered by vegetation, with clear outlook – Spotted flycatchers
3-5m high up with clear flight path, on a tree trunk – Woodpecker.

Make or buy a bird house

You can have a go at making your own bird box based on these dimensions. Or if your woodwork skills are not what they used to be, take a look at the range of bird houses and nest boxes available from Dobbies online.