In this guest post wildlife gardening writer, Jan Miller-Klein, provides step by step instructions on how to build a birds nest box. As well as covering why this is so important for our local wildlife.

It wasn’t until I was about 30 that I realised that wild birds don’t live in nests all the time. They only build them to rear young, the rest of the time they roost in hedges, trees, reeds etc. But the way we are taught about wildlife as children is so anthropomorphic that a bird’s nest has to be described as its ‘house’. The ‘Jungle’ is still used as a backdrop in stories about animals that live on the Savannah; American kids I taught in the Netherlands thought there would be raccoons, cougar, fireflies and hummingbirds ‘out there’ in the European countryside; that’s what their cartoons, computer games, films and storybooks show them.

It has always surprised me how inaccurately we learn about the natural world – well most kids know that animals don’t wear clothes (why does Donald Duck always wear a jacket, hat and no trousers?), but there’s still a lot more to find out.

So I have just started a kids Wildlife Watch group, under the auspices of my local Wildlife Trust. Last week we made nestboxes from kits kindly made for us by an elderly volunteer called Betty, out of floorboard timber. She has a rig set up in her garage to cut the pieces to the right shape and measurements (different species need different sized entrance holes). The 25 kids that turned up – ages ranging from 5 to 13 - with their parents, had fun putting the pieces together and then took them home to put up in their own gardens. This gives them a reason to watch what goes in and out of them, and this is just the right time of year to do it as our wild birds come into their breeding season. We also made bird feeders by mixing lard with seed and pressing it into a pine cone.

 How to Build a Nest Box

To make your own nest box like Betty’s you just need;

  • 5 pieces of rough floorboard or recycled timber
  • a backboard 36cm x 14.5cm.
  • two sides with slanting top edge 20cm x 25cm x 15cm wide.
  • a front 20cm. x 14.5 cm.
  • a lid 23cm.long x 14cm. wide.
  • a bottom cut to fit when you have assembled the rest

The design is cleverly made to fit on a tree or a fence by having just one big hole at the top of the backboard and a notch at the bottom to put in another nail for stability, after hanging on a large nail at the top. This means the whole box can be lifted off for inspection and cleaning (in the winter - when no birds are in there of course!)

 Building a birds nest box

1. Look at the photo of the completed box and place the back on the sides the right way (so the box will hang off a nail in the tree when it’s put up

2. Screw the back into one of the sides

3. Turn over and screw the front to the side, lining up carefully to give a flush join so that there will be no gaps when the lid is closed. Screw the other side to the back

4. Place the lid on the box upside down and pencil in. Screw two screws in a short distance and check that you can open the lid and that the screws hold the lid in place. Do not fasten the lid to the box yet

5. Hold the box over the small plank and pencil the cutting line so that the piece will fit snugly inside the box forming the bottom. Make drainage holes and saw it off the plank. Fit it inside the bottom of the box and screw it in

6. Now offer up the lid firmly in position and hammer clout nails through the  plastic hinge to hold the lid in position

7. To hold the lid down use two screws and wire as on box photo

8. Paint the outside of the box with animal and bird safe stain to preserve and camouflage the box; do not paint the inside or the hole itself as the smell may put the birds off

building a bird box

Positioning The Box

    1. Find a position for the box so it’s facing approx. NE and a few metres above the ground.  (Not robin boxes which should be less than 2m above the ground and well hidden in vegetation.) Do not have the box on a trunk slanting upwards because rain could get in. 


bird box plans

    2. Drive in the big nail at an angle until it is firm and is not going to fall out – but most of the nail should be sticking out. Hang the box on the nail. Take the small nail and hammer it through the little slot at the bottom to stop the box from swaying. 
    DO NOT drive the nail in too far. This design allows you to quickly and easily remove the box for cleaning.  
    Bird Health 
    After use the RSPB suggest using boiling water to sterilise the box. I find a blow torch much simpler but do try to scrape out all the woodlice, earwigs, spiders first! 
    By using screws instead of nails the boxes can be easily repaired. 
    This exercise made me realise that we only help a small number of species with putting up nestboxes – the hole-nesters like Tits, sparrows, robins, nuthatch, etc. Other garden birds like Blackbird, thrushes, finches and many more have to find their own nest sites in suitable deep cover like hedges, brambles, fir trees that may be just as absent as old holey trees. The peanut, fat and seedfeeders we put out also favour a small range of birds; so we are preferentially selecting out the birds like Blue tits to become more common. Is this good or bad? I can’t decide, but at least we are helping some wildlife to survive the onslaught of human activity, and helping a new generation of children to think about it.