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How to make a bat box

You will need

  • Plank of rough-sawn untreated wood 120cm x 20cm x 2cm
  • 19cm x 4cm long nails and hammer
  • 1 x metal eyelet with a 1cm diameter
  • Pencil, wood saw, ruler
Do it: February - October
Takes just: 2 hours


A bat box works on the same principle as a bird box, except that bats prefer a wedge-shaped roost and enter through a gap underneath rather than a hole at the front. Using cheap, untreated wood, this box will give bats the perfect place to shelter and roost in your garden. If you're lucky, they may even give birth and raise their young there, so make sure you site it in a sheltered spot.

How to do it

Attach the side panels


Using a pencil, divide and cut the plank into the following sized pieces: 40cm x 15cm (back), 23cm x 20cm (roof) and 23cm x 15cm (front). Finally cut a piece 20cm x 34cm and cut it diagonally to create two triangles for the sides of the bat box. Place the backboard on a flat surface and cut ridges into it, 2mm deep every 0.5cm, to make a 'ladder' for the bats to climb up.

Take one of the side triangles and measure 12.5cm from the acute angle along the longest length. Draw a horizontal line across the triangle at this point and cut off the smallest part. Repeat with the other side. Nail the two side panels to the front panel of the bat box. Sit the roof on top and push up the backboard to check for a tight fit. Nail on the backboard. Nail on the roof and an eyelet for hanging and hang above ground on a tree, post or house wall.

Our tip

Rough sawn wood is ideal for giving bats something to cling onto, but if you can't find any then roughen it with saw cuts to help them cling properly.

To give bats the chance to choose the most suitable roost for the particular time of year site three boxes in your garden facing north, south-west and south-east.

Discuss this project

Talkback: How to make a bat box
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ebbypea 24/11/2011 at 15:28

I love bats, we sit in the conservatory at night to watch the bats swooping above us. I hope i can make a good one because I will be so chuffed with myself, and hopefully it may encourage more bats in my garden. Thankyou for the tips.

Richardjulian 24/11/2011 at 15:28

do you really mean to use nails 19cms by 4 cms? Wouldn't it be easer to use smaller nails!

mikehinson 24/11/2011 at 15:28

It seems you measure 12.5cm from the top acute angle, not the bottom one, which wastes quite a lot of wood, but gives the right size opening and a smaller box...I've made 2 boxes, both ways

Richardjulian 24/11/2011 at 15:28

You need 45 or 50mm long oval wire nails not as above; Step 3: the entrance hole needs to be 15-20mm. if you cut off 12.5cms the hole will be too big and you will then need to attach a piece of plywood to reduce the size, which is what I have had to do. If you cut less off the triangles, you will not have enough wood for the front.

tim.gardener 24/11/2011 at 15:28

On it is recommended to place batboxes due South. Other sites have similar recommendations. Are you aware of this and if so, is NE, NW and SE really better?

The argument for a due South planig is that youngh bats "need warmth". The USA site even recommends painting the South facing wood in black latex.

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