Biodiversity Net Gain

As a landowner, you can receive a payment in return for wildlife-friendly land management, to mitigate the ecological impact of development elsewhere.

What is Biodiversity Net Gain?

Biodiversity Net Gain (BNG) is an approach to development required from January 2021 that leaves biodiversity in a better state than before. Where a development has an impact on biodiversity it encourages developers to provide an increase in appropriate natural habitat and ecological features over and above that being affected by the development.

The biodiversity net gain (BNG) requirement means that any new development will need to not only leave biodiversity in as a good a state as it was before the development; it will actually need to be improved by 10%.


It is this government’s ambition under its 25 Year Environment Plan to leave the environment in a better state for the future.

How does it work?

Biodiversity Net Gain relies on the application of the mitigation hierarchy to avoid, mitigate or compensate for biodiversity losses.   

Developers use Defra’s biodiversity metric, based upon a habitat survey of the proposed planning site, to calculate the pre-development biodiversity score (in biodiversity units) and a projected post-development value, allowing the difference to be measured.


What is a biodiversity Metric?

A biodiversity metric is a tool used by ecologists to measure changes in biodiversity. Several such tools have been developed, most recently the Defra Biodiversity Metric 2.0.

Metrics assign every habitat on a site a ‘unit value’ according to its relative importance for biodiversity. This enables comparison between the existing value of a site and what will be delivered through development or management.


Opportunities for landowners

Where it is not possible to achieve the required uplift on site, a developer can partner with a local farmer or landowner, who can implement measures on their land to increase biodiversity by the required amount and receive a payment from the developer for doing so.

BNG will allow landowners to identify parts or areas of their land holdings that they wish to take out of production and place in to a long term environmental project.

Landowners receive a payment which will tie up the land for 30 years.

Currently, the amount paid is subject to negotiation.

The long term management of the land remains under the control of the land owner.


The ownership of the land remains unaffected. There are no statutory designations or access requirements imposed beyond the agreed management plan.


If you are interested in getting involved in a BNG development, the first thing you will need to assess is the level of uplift that could be achieved on the land offered.  Laurence Gould can assist with this.



The National Planning Policy Framework (NPPF) places a responsibility on local planning authorities to encourage net gains for biodiversity to be sought through planning policies and decisions. This allows the local planning authority to determine how BNG is assessed and enforced within their jurisdiction.

The Environment Bill sets out the mechanism by which biodiversity net gain from development is to operate. Planning Authorities will have a duty to implement the requirement for developers to deliver biodiversity net gain (BNG) on all developments covered by the Town & Country Planning Act (1990).

Registration: If you are a developer who requires BNG or a landowner who can provide BNG  please contact or Charles Baines on 01223 813622, and we will work out a suitable mitigation plan and broker a deal.