Birds and chimneys
Birds nesting in your chimney: what you can and cannot do
A nest in the stack is a wildlife-law question before it is a roofing one. Here is what the law protects, what has to wait, and what keeps birds out.
The short answer
You can clear an old, empty nest, but once birds are using a nest, or are still building one, the Wildlife and Countryside Act 1981 protects it from anyone who removes or wrecks it on purpose. If birds are using the stack, chimney work waits until they have finished with it. A cap or cowl fitted afterwards stops the next nest.
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What the law protects and what it leaves alone
Section 1 of the Wildlife and Countryside Act 1981 sets out the offence, which applies to someone who intentionally takes, damages or destroys any wild bird's nest during the period when it is in use or being built. Two phrases carry the weight. "Intentionally" means someone who sets out to remove the nest. "In use or being built" means the protection covers a nest that has birds in it or is going up, and says nothing about one left empty.
The government's wild bird guidance on GOV.UK states that licences are not granted for development or construction purposes. In plain terms, a roof job or a chimney repair is not a licensed reason to remove an occupied nest. The work moves to suit the birds, and the birds do not move to suit the work.
That is why a survey of a stack with a nest in it begins with a question instead of a ladder. Is anyone at home? If so, we tell you, leave the stack alone and agree a later date for the repair. If not, the old nest comes out as part of the job, along with whatever has dropped into the flue.
How to tell whether a nest is in use
The Wildlife and Countryside Act 1981 protects a wild bird's nest while it is in use or being built, whatever the month, so the calendar is not a safe test. The nest is. From the ground, with binoculars or the zoom on a phone, you can look for the following.
| What you see or hear | What it points to |
|---|---|
| A bird carrying twigs up to the pot | A nest being built: leave it |
| Parent birds flying in and out, calling from the pot | A nest in use: leave it |
| Chirping from inside the flue or fireplace | Young birds in the stack: leave it |
| Twigs in the grate, no birds seen over several days | Possibly empty: a roofer confirms from the roof |
Sticks and soot in the grate do not prove the nest is empty, since material can fall while birds are still in residence. Do not push a brush up the flue to find out, and do not tap on the pot to make them leave. If you are unsure, take a dated photo or two and send them to us before anyone goes up.
Bats and other animals in the stack
Birds are not the only tenants. Section 9(4) of the same Act makes a person guilty if they intentionally or recklessly disturb a protected animal while it occupies a structure it uses for shelter, or obstruct its access to that place. The Conservation of Habitats and Species Regulations 2017 go further for bats: harming a breeding site or resting place is an offence whatever the intent. GOV.UK includes roof repair and replacement in the work that can disturb a bat roost, which is why the question comes up on a roof at all.
If you see bats at the stack or the roof edge, or find droppings below it, stop and say so before work is planned.
- Do not block the gap where they are seen to enter.
- Do not light a fire or use smoke in the flue.
- Photograph what you see, without handling anything.
- Tell us the spot, so the survey notes it.
A wild animal sharing the stack changes the order of the job and sometimes its timing. It does not stop the repair for ever, but the repair follows the animal's use of the space.
Clearing the stack and keeping birds out
Once the nest is empty, the next job is stopping a repeat. The answer is a cowl, a cover that fits over the pot, or a cap where the flue is no longer used. Which suits you depends on what the flue serves, and our page on replacing a chimney pot and fitting a cowl sets out those choices. If the stack leans or the brickwork is breaking up, the nest may be the smaller problem, and the survey will say so.
While we are up there, the survey looks at everything that sits near the nest:
- the pot, for cracks and for any nest material wedged into it
- the mortar bed round the pot's base, which birds can pick at
- the lead strip sealing the stack to the slope
- how we reach the stack safely, which may mean scaffolding
You then get one written total price for the work the stack needs, and nothing begins until that price is agreed. Our chimney repairs page shows the full range of stack work, from repointing to a rebuild.
More questions
Can I remove a bird's nest from my chimney myself?
Only if you are sure the nest is empty and out of use. The offence applies to a nest in use or being built, and it turns on the word intentionally. If you cannot see whether birds are using it, do not disturb it. Send us a photo and we will tell you what the survey needs.
Will a cowl stop birds getting into the flue?
A cowl is made to cover the pot's outlet, so birds cannot drop into the flue, but the fit matters. It has to suit the pot and the flue's use. If a stove or boiler flue is connected, check with the engineer who services it before anything is fitted.
Tell us what's wrong with the roof.
You'll get one written total price.