Smaller farm buildings to escape mandatory BNG assessments

Farmers planning developments of less than 0.2 hectares could avoid mandatory Biodiversity Net Gain assessments under rules taking effect on 6 August 2026.

The exemption is expected to cover some smaller agricultural projects, including livestock sheds and slurry lagoons, provided they do not affect priority habitats.

Schemes exceeding the 0.2-hectare threshold, or those affecting priority habitats, will remain subject to Biodiversity Net Gain requirements.

The Government said the reforms were intended to simplify the Biodiversity Net Gain process, with fewer small developments required to undergo mandatory assessments.

H&H Land & Estates said the change could reduce survey costs, delays and administrative work for qualifying farm businesses.

Andrew Boles, environment and conservation adviser at H&H Land & Estates, said: “For many farmers this is a welcome and sensible change.”

He said the existing requirements had brought environmental benefits but had also added cost and complexity to relatively straightforward agricultural developments.

Some businesses have previously had to commission ecological surveys and provide biodiversity mitigation for projects considered essential to their daily operations.

In some cases, this has involved taking productive land out of agricultural use and accepting management obligations lasting up to 30 years.

Mr Boles said the new exemption should make it easier for some businesses to invest in smaller developments, but warned that it would not apply in every case.

He said: “However, it is important for landowners not to assume all developments will be exempt.”

The exemption will apply to new planning applications submitted from 6 August 2026.

A separate temporary development exemption will also be introduced where land is fully reinstated within five years, unless priority habitat is affected.

Changes to the biodiversity gain hierarchy will allow some minor developments to move directly to off-site biodiversity provision where appropriate.

At the same time, the existing exemption for self-build and custom-build developments will be removed.

Further reforms are expected, including possible exemptions for developments primarily intended to conserve or enhance biodiversity.

The Government is also considering targeted exemptions for improvements to parks, playing fields and public gardens, alongside changes to the statutory biodiversity metric.

Mr Boles advised farmers and landowners to seek professional guidance before submitting an application.

He said: “Although these changes represent a significant step forward for many farming businesses, every planning application should still be considered on its own merits.”