Last July we wrote about the quieter fight next to Felton Common — the threat to irreplaceable habitat at Cook’s Farm from Bristol Airport’s plan to expand from 12 to 15 million passengers a year. We lodged a detailed objection. Our central point was simple: the airport wanted to bulldoze centuries-old habitat but its evidence didn’t add up, and the law said that should matter.
The airport has just responded by publishing a large tranche of ‘further information’ — an updated Environmental Statement, revised reports, and, for the first time, its full Biodiversity Net Gain calculation as a working spreadsheet. It was meant to answer North Somerset Council’s questions and to shore up the application.
It does just the opposite: the airport’s new evidence now confirms what we said in May — and in one respect it makes the case against the application considerably stronger. Here’s what has changed.
The airport now admits its plans will lose five veteran trees
In May we argued that the veteran trees the airport proposed to ‘translocate’ should be treated as lost, because moving trees of this age is a high-risk operation that almost never succeeds. The application originally presented the loss as a single tree, then three.
The airport’s own updated evidence now records the loss of five veteran trees. Its biodiversity spreadsheet puts it plainly: the affected trees ‘comprise a total of 5 ancient/veteran trees… all are in good condition. All of these will be lost.’ Translocation is now proposed for only three of the five — which is, as we set out before, just a plan to kill them slowly rather than a genuine solution.
We are not the only ones to reach this conclusion. North Somerset Council’s own ecological reviewer told the airport that treating translocated veteran trees as ‘retained’ is ‘inappropriate’ and that any veteran tree that cannot be kept where it stands ‘should be considered ‘lost’’. The airport has now accepted this. It’s a significant admission: the true scale of irreplaceable-habitat loss was understated when the previous evidence was submitted.
The data we were refused — and what it reveals
In May we recorded that we’d asked for the airport’s survey data and biodiversity metric in a usable spreadsheet form so the figures could be checked — and that our request had been refused, leaving us to analyse the evidence ‘as best we can’.
The airport has now published the full metric as a working spreadsheet. We welcome that; it is what should have accompanied the application from the start. Now that the numbers can actually be interrogated, they tell a striking story.
Nearly every major development must now deliver a biodiversity net gain of at least 10% — it must leave nature measurably better off. The airport’s own metric shows the reverse. On its own figures the scheme produces a net loss of around 32.5% in habitat units and 27.4% in hedgerow units. The spreadsheet flags, in its own words, that ‘net gain is less than target set’, and even warns that there are unresolved ‘input errors/rule breaks’ in the calculation. No off-site provision has been entered to close the gap, so the shortfall stands.
In other words: a scheme that is legally required to improve biodiversity by at least 10% would, on the applicant’s own arithmetic, destroy roughly a third of the site’s habitat value instead.
Breaking the trading rules
There is a further, more fundamental problem. The biodiversity metric has ‘trading rules’ that stop developers seeking to compensate the loss of valuable habitat by creating less valuable habitat somewhere else. Lose species-rich calcareous grassland, ancient hedgerow or veteran trees, and you must replace them with the same thing or better — you can’t swap them for a patch of ordinary grass and call it even.
The airport’s own spreadsheet records these rules as not satisfied — for its high- and medium-value grassland, and for its hedgerows. To meet both the 10% target and the trading rules, the airport would need to find, of the right type and quality, roughly 241 units of new habitat and 31 units of hedgerow — the great bulk of it medium-or-higher-value grassland, plus around 20 units of species-rich native hedgerow. None of this has been identified, on site or off it.
And the veteran trees sit outside the system entirely: as irreplaceable habitat, no quantity of new habitat can compensate for them at all.
Still no real compensation
That last point is key. National planning policy says that development resulting in the loss or deterioration of irreplaceable habitats such as veteran trees (there are at least 21 on site) should be refused unless there are wholly exceptional reasons and a suitable compensation strategy already exists. Asked in its own spreadsheet whether bespoke compensation for the veteran trees has been agreed, the airport’s answer is a single word: ‘No.’ Its updated documents describe only an ‘emerging’ strategy that ‘may include, but may not be limited to’ moving three trees — unwritten, unagreed, and left to be sorted out later.
The airport may say the details can be settled after permission is granted. For ordinary habitat, that may be partly true, but for irreplaceable veteran trees, and for the protected bat habitat this scheme also affects, a secured solution is required now, at the decision stage — not promised for the future. None has been provided.
The hedgerows matter too
It is worth remembering what some of these hedgerows are. Native and species-rich hedgerows are a ‘priority habitat’ that national and local policy require to be protected and enhanced. And as we noted in May, nearly all the hedgerows on Cook’s Farm appear on the tithe maps of the 1840s. Hedgerows that old and that rich in species are very likely to be ‘important’ hedgerows under the Hedgerows Regulations 1997 — a status that brings its own legal protection against removal. The airport’s further information still doesn’t identify which of the hedgerows it wants to grub out are ‘important’ in this sense. It should.
And Felton Common?
The proposals for Felton Common — the 8.5-metre high approach lights and fencing across protected grassland — are essentially unchanged, now described in more detail. For the record, that grassland loss is folded into the very same biodiversity sums that already fail to add up.
Where this leaves things
The airport had a chance to fix the problems we identified in May. Instead, its further information only confirms them:
- It now admits losing five irreplaceable veteran trees in good condition, with no agreed way of making up for them.
- Its own biodiversity calculation shows a net loss rather than the required gain.
- It breaks the rules that are meant to stop valuable habitat being traded away for less valuable habitat.
- The compensation remains a mere promise rather than a plan.
Our position is unchanged: we say these problems must be resolved before the application is decided. On the evidence now available, the Council should refuse it. For everyone who cares about Cook’s Farm — its ancient hedgerows and the veteran trees standing in them — this remains the line worth holding.
You can read our full response to the airport’s further information here:
BTF – Supplementary Comments – 30 September 2026
