Bat roosts and roof works under permitted development

Permitted development rights grant planning permission. They grant nothing at all under wildlife law. Bats and roof works under permitted development is the scenario where that gap does the most damage, because a re-roof or a loft conversion needs no planning application, so nothing in the process prompts anyone to ask whether the roof holds a bat roost. The homeowner books a roofer, the felt comes off in July, and the first anyone knows about it is when something flies out.

All bat species in the UK are protected under the Conservation of Habitats and Species Regulations 2017 and the Wildlife and Countryside Act 1981. It is an offence to damage or destroy a breeding site or resting place, and that offence does not depend on bats being present at the time. The roost is protected, not just its occupants. A roof used by bats in May is still a protected roost in January.

Why wildlife law applies regardless of planning

The two regimes are separate statutes with separate enforcement. Planning is administered by the council. Bat protection is enforced by the police, with Natural England as the licensing authority, and the offences are criminal.

Nothing in the General Permitted Development Order grants a defence. Nor does a planning permission, a building regulations approval or a Lawful Development Certificate. Where works would affect a roost, a licence from Natural England is required before the work starts, and the licence is granted on tests about purpose, alternatives and favourable conservation status rather than on planning merits.

So the sequence for a loft conversion or a re-roof on an older building is: check for bats, then design, then build. Not the other way round.

When a preliminary roost assessment is needed

A preliminary roost assessment is a daytime inspection by an ecologist who looks for bats, droppings, staining, feeding remains and the gaps a bat can use. It takes a couple of hours and it is the only proportionate first step for most householder projects.

Commission one where any of these apply:

• The building is pre-1960, or has a slate or clay tile roof on battens with gaps.
• There are soffit, fascia, bargeboard or ridge gaps, or lifted flashing.
• The roof void is unlined, or has bitumen felt rather than a modern breathable membrane.
• The building is near woodland, water, hedgerows, a park or a church.
• Neighbours have reported bats, or there is a known roost nearby.
• The works involve stripping the covering, removing the felt, opening the ridge or cutting dormers.

A modern house with a sealed membrane roof and no gaps is low risk, and an ecologist will say so in a short letter. That letter is worth having, because it is the record that the duty was considered.

Survey seasons and the programme consequence

The assessment can be done at any time of year. The follow-up surveys cannot, and that is where programmes break.

Where the assessment finds moderate or high roost potential, published good practice expects a number of emergence or re-entry surveys spread across the season, with the number increasing with the assessed potential. The Bat Conservation Trust's good practice guidelines set out the expectations, and ecologists follow them because Natural England does.

The practical consequence is blunt. Commission the assessment in February and you can survey in May and build in August. Commission it in September and you are waiting until the following May. For a householder paying for scaffolding and a contractor's slot, that is the expensive mistake, and it is entirely avoidable by making the call early.

Licensed works and supervision of the roof strip

Where a roost will be affected, Natural England licensing is the route. Two forms matter for domestic work.

A European protected species mitigation licence is the full application route, prepared by an ecologist with a method statement, mitigation design and a monitoring commitment. Determination takes weeks, so build it into the programme.

A low impact class licence allows a registered consultant to authorise certain low impact works on small roosts without a separate application, subject to the works and the roost meeting the published criteria. It is faster and it is the normal route for straightforward householder jobs. Whether a scheme qualifies is a judgement for the registered consultant, not for the homeowner.

Either way the works are supervised. The roof strip is done by hand in the affected area, in agreed conditions, with the ecologist present, and replacement roosting features such as bat access tiles or a maintained void are installed as specified. Build that into the contractor's programme and price it, because a roofer who has to stop for supervision on a day he had priced as a full strip will charge for it.

A Protected Species Survey and any mitigation licence require a suitably licensed ecologist under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017. An AI-assisted draft is a starting point for that professional rather than a substitute for them.

Offences and who is liable

Liability is wide, which surprises people. The homeowner who commissions the work, the main contractor, and the individual operative who removes the tiles can each commit an offence.

Damaging or destroying a breeding site or resting place is the offence most often committed on roof works, and it does not require intent. Deliberately killing, injuring, capturing or disturbing bats are separate offences. Penalties include fines and, for some offences, imprisonment, and the equipment used can be forfeited.

Contractors should ask, and good ones do. A clause in the building contract requiring the client to confirm that ecological checks have been carried out protects both parties and costs nothing.

An illustrative example

Illustrative only: a 1890s cottage with a slate roof, re-roofed under permitted development with no planning application involved. The homeowner commissions a preliminary roost assessment in March. The ecologist finds droppings on a beam and assesses moderate potential, so two emergence surveys are carried out in June and July, confirming a small roost of a few individuals under the ridge. The ecologist registers the work under a low impact class licence, the ridge is stripped by hand under supervision in August, and two bat access tiles and a maintained void are provided in the new roof. The scaffolding goes up once. Had the assessment been left to October, the same job would have waited nine months.

What to do if bats are found mid-works

Stop immediately. Do not continue in a different part of the roof, and do not move or handle the bats.

Then: cover the opening loosely to keep the roost conditions stable, record what was seen with photographs and the time, contact an ecologist and the National Bat Helpline run by the Bat Conservation Trust, and contact Natural England about licensing before any further work. Tell the contractor to secure the site and leave it.

Carrying on after bats are found converts what might have been an accident into a deliberate act, and that is the difference the enforcement authorities look at.

Keeping the records afterwards

Keep everything for the life of your ownership and hand it on at sale. The preliminary roost assessment and any survey reports. The licence or class licence registration and its reference. The method statement and the supervision records. Photographs of the mitigation features installed and their positions. And the invoice showing who did the work.

Two reasons. A future buyer's surveyor may ask, and a roost that was lawfully modified under licence has a paper trail that shows it. And if an allegation is made later, contemporaneous records are the evidence that answers it.

Where a planning application is also needed for other parts of the project, a Preliminary Ecological Appraisal usually sits alongside the bat work, and a Planning Statement should record the ecology position rather than leaving it to the case officer to raise. A bat survey is the document most councils name in their validation lists. Enter your postcode on PlanScope to see which reports a site with roost potential is likely to need.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.