Trees are the odd one out

Most habitats the BNG rules deal with — grassland, scrub, hedgerows etc. — can, in principle, be recreated somewhere else within a few years.

Plant a replacement tree for one felled and it starts life as a sapling and will take (assuming it lives long enough) years to do what the felled tree was already doing: a mature tree takes decades to mature and at least nine saplings to replace just one. The largest trees would need at least 19 new trees and still take many years to ‘replace’.

And a tree’s real value — the shade and cleaner air it provides us, soaking up rainfall, its character and the nature it shelters that you see daily — is delivered exactly where it stands. Move the ‘replacement’ to a distant field few will ever visit and, while you may have ‘ticked the replacement box’, you have lost the thing that mattered – your local, everyday tree.

That is the backdrop to the changes now coming.

Clearing trees here, ‘making up for it’ miles away

For slightly larger sites, one proposal would let developers skip trying to keep trees on the site and instead allow them to pay for replacement habitat (not necessarily trees) somewhere else — potentially a long way off. The mature tree that was growing near you, ‘replaced’ by a patch of new grassland or scrub far away in some ‘foreign field’ you cannot visit. The paperwork balances but your tree is gone.

A much bigger exemption for brownfield sites

This could be the big one for towns and cities. The Government has floated exempting brownfield sites of up to 2.5 hectares — more than ten times the size of the small-sites limit. Brownfield and urban plots are exactly where many mature street trees grow, so an exemption on that scale could wave through a lot of tree loss. It is still just a proposal and a final decision is awaited, but the threat is real.

‘Temporary’ felling that lasts forever

Another idea would exempt “temporary” development — anything that can put back within five years. That may be fine for many habitats, but not for trees: you cannot regrow a mature tree in five years. Fell it for a short-term purpose and it is gone for good.

Trees removed in the name of nature

One proposed exemption covers work to improve parks, playing fields and public gardens, or projects whose main aim is to help wildlife. Well meant — but these are often the places where big, mature trees grow. If the ‘improvement’ means cutting trees down — for example, to create open grassland or a play space — there would be no obligation to plant replacements.

Why it adds up

On their own, each of these is a small technical tweak. Together, they push in one direction: it becomes easier to remove the trees closest to where people live, and to offset them — if at all — with habitat elsewhere. The result, over time, is fewer trees in our neighbourhoods and the inevitable ‘greying’ of our urban spaces.

The older protections for trees still stand — Tree Preservation Orders, conservation-area rules, and protection for ancient and veteran trees — along with any local tree protection policies your council has adopted, but these are not always fully applied. Even so, this is exactly why these protections will matter more than ever.

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Read the full briefing note here

Our earlier companion post is also available here – The small-sites rule change that could quietly cost your neighbourhood its trees