How Biodiversity Net Gain Became More Than Just a Buzzword


While biodiversity has been a topic of great importance to humanity, biodiversity net gain(BNG)has recently become a term to take note of. Royal decree has legislated BNG, and numerous structures are being designed and have already been created to contend with the impact of development on biodiversity. This mandates certain additional requirements before the local council will approve a development application. Every developer needs to be aware of the changes and what they must do to comply.

Despite previous legislation, including that of the EU before Brexit, biodiversity has decreased by 13% since 1970. Biodiversity net gain is being implemented with strict reporting mechanisms and structures to ensure adherence to the new law. Authorities are still determining what consequences should be applied to defaulters.


Biodiversity denotes the variety of species found in an area, ecosystem, or even globally. It is
estimated that there are around 8.7 million distinct species made up of fauna, flora, fungi, and
bacteria. However, only 1.2 million have been named and described by biologists.

Species adapt to survive and thrive. Every organism is both prey and predator. This maintains a
delicate equilibrium in an ecosystem so that the whole is healthy and the parts flourish. Yet, the
actions of humans have put many species at risk, of which many have become endangered or
extinct. This upsets the balance nature tries to preserve, with negative effects on all life on earth.

Although species do become extinct without mankind’s interference, the extinction rate is 1000
times greater than it would be without humans. One of the major threats to the planet is the
development of land for commercial or residential properties at the expense of biodiversity. Humans
may face extinction too if this dire situation is not turned around quickly. Before that happens, we
will be without healthy air to breathe, unpolluted water to drink, and food sources.

Legislation Has Made BNG Mandatory

Legislation is the outward cause of BNG gaining so much significance of late. Once something comes
into law, it is no longer optional. Developers who previously paid scant attention to preserving
nature and biodiversity now have to toe the line if they want their applications to be approved by
their local council. Non-compliance will result in consequences.

The Environment Bill was released in 2019. This has since been ratified by royal assent, resulting in
the Environment Act. The Act requires new developments to achieve a 10% BNG, effective
November 2023. Several local councils have already instituted the Act’s requirements. In addition to
the increase in BNG, ecosystems must be sustained at this level for a minimum of 30 years.

Other provisions of the Environment Act are compulsory conservation and biodiversity duties
imposed legally on public institutions, local councils to adhere to amended biodiversity reporting,

and Local Nature Recovery Strategies (LNRS). The Act also had to fill the gap left by biodiversity legislation regulated by the European Union, pre-Brexit.

Other legislation that fed into the Environment Act are the amended Wildlife Countryside Act of
1981, the Natural Environment and Rural Communities Act of 2006, the Conservation of Habitats,
the twice revised National Planning Policy Framework of 2012, and the Species Regulations of 2017. 

What Is Biodiversity Net Gain?

When developing land, the biodiversity of the site is compromised. Thus, it is incumbent on those
involved in preparing and submitting planning applications to restore the biodiversity to its original
level plus improve it by ten percent (on-site) or deliver this required quantity and quality of
biodiversity augmentation at another location (off-site). The sites must be preserved accordingly for
three decades.

How Is Biodiversity Net Gain Calculated?

The DEFRA biodiversity metric is used to calculate BNG. It was devised by Natural England. The first
version (2.0) came out in 2019. In 2021, version 3.0 was released. Biodiversity Metric version3.1 took over in April 2022. It will remain in place for three to five years. The Small Sites Metric was developed for use in calculating BNG for small developments.

The DEFRA biodiversity metric measures the biodiversity level of a site. This figure is called either
biodiversity credits or biodiversity units. The developer is required to increase this score by ten

If it is not possible to increase the development site’s biodiversity, developers can pair up with
landowners who lack funds to improve their lands. Developers will purchase the requisite number of
biodiversity units from these owners. The number of biodiversity credits that must be purchased is
the shortfall of the 10% required improvement that cannot be realised on-site. Hence, it will occur

The landowner has to sign a contract that is valid for 30 years. This document stipulates the
requirement to unfold the net gain plan that was detailed and approved by the local council for the
development application. Anyone who succeeds the landowner as the title holder of the property is
bound by this legal agreement. This is regulated by the Wildlife and Countryside Act, Section 39.


Stakeholders play a huge role in driving these changes, refining BNG measurement techniques, and
monitoring compliance. Along with the Environment Act, they are part of the reason why
biodiversity net gain became more than just a buzzword.

Natural England is responsible for the creation of the DEFRA biodiversity metric. They liaise with the
government and other parties to refine the tool further. DEFRA is the public entity of the
Department for Environment, Food, and Rural Affairs.

Natural Resources Wales is also an involved stakeholder. Other institutions that are involved in biodiversity conservation are the Nature Recovery Network, the British Standards Institute (BSI), the Natural Capital Committee, and Local Nature Recovery Strategies. Local councils play a direct role by being the decision-makers who approve or decline development applications.

How to Obtain Biodiversity Assessments and Net Gain Plans

Biodiversity Assessments and Net Gain Plans should be prepared by experienced ecologists who will
undertake a site visit to perform their appraisals and devise a plan for you. Biodiversity Net Gain Plan has around 30 ecologists with over a thousand assessments behind them in the past year alone. This
makes them experts in BNG and the specific requirements of your local council.
Biodiversity should be the concern of every person on the planet. With the new law in place, the
topic will continue to be discussed and BNG implemented to save the future for all species in the UK.