The short answer
Sometimes, but not over an active nest. Under section 1 of the Wildlife and Countryside Act 1981, intentionally wrecking an occupied or half-built nest is an offence, and GOV.UK lists no licensing purpose for development or construction. Work has to be planned around the nest, which usually means leaving that stretch of roof until the birds have finished.
What the law says
The offence in section 1(1) of the Wildlife and Countryside Act 1981 needs intent: intentionally wrecking an occupied or half-built nest is what the section catches.
The word that does the work is intentionally. It would be wrong to say that disturbing a nest is always illegal, and it would be just as wrong to say that it never matters. A roofer who knows a nest is active and goes ahead anyway has a problem. A person who had no idea a nest was there is in a different position, though that is no reason to be careless.
GOV.UK adds a point that surprises people: it lists no licensing purpose that would allow development or construction. In practice, a householder cannot buy permission to clear an active nest in order to get on with building work.
The law does not fix dates, and we do not rely on a calendar to decide whether a nest is likely. What matters is whether a particular nest is occupied on the day.
This page gives general guidance and is not legal advice. If you are unsure, say so to the roofer and ask for the job to stop until the position is clear.
Finding out whether a nest is active
The best time to find out is at the survey, ahead of any scaffold booking. Birds nest in eaves, behind fascias, under tiles at the verge, in gaps beside chimneys and in the angle of a dormer. A look around the outside and a look in the loft will show most of them.
Signs of use are straightforward. Look for birds carrying material, an adult flying repeatedly to the same spot, chirping from a gap, droppings beneath, or straw and twigs poking out of an opening. A lone old nest that is cold and still may be inactive, but do not assume it.
Photographs help. A dated picture of the nest, with its position on the roof, becomes part of the job file and shows what was known at the time.
Tell your roofer about anything you have noticed. You see the building every day, and a pair of swifts or house martins coming back to the same corner is something you will know before anyone else.
Where a nest turns up after the work has started, stop at that spot, leave the nest alone and tell whoever is in charge. Do not move the nest to make progress.
Planning the job around an active nest
The practical answer is to plan around the nest and not to remove it. Work on the other side of the house can usually go ahead, which keeps the scaffold hire from being wasted. The affected stretch of eaves, verge or ridge waits until the birds have moved on, and the order of work is adjusted to fit.
That affects the programme. The scaffold may go up, parts of the roof may be done, and the rest completed on a second visit. Tell the roofer that this is acceptable, and ask for the revised order in writing.
Sometimes a nest sits in a place that has to be dealt with, such as a failing soffit with a gap above it. Then the timing of the repair is the issue, and the safe approach is to wait. A temporary measure may be possible without touching the nest.
Once the birds have gone, the repair can be done and the gap closed, ideally with a detail that keeps rain out without blocking ventilation.
We would rather schedule the work around a nest than risk causing harm, and the survey notes record what is found. Our answer on bats found during roof work covers the stricter position for roosts.
After the birds leave
When a nest is no longer in use, you can ask the roofer to clear it and close the opening. Do this only when you are confident that the birds have finished, and keep a note of what you saw.
Think about prevention at the same time. Closing small gaps at the eaves and verge with the right materials stops repeat nesting, but the detail matters. A solid closure at a soffit can cut ventilation, and a roof needs a flow of air in the void. The roofer should show you how the fix keeps air moving.
If swifts, house martins or other birds you want to keep use your house, you can discuss leaving a space for them, or fitting a nest box nearby. That is your decision, and the job can be shaped around it.
Guttering, fascias and soffits are among the parts affected. Our service page on guttering, soffits and fascias covers the repair work.
The broader picture of how we survey and plan a roof is on the homepage.
