The Environment Act 2021 and Biodiversity Net Gain

The world is slowly going green. But, before change can be made, it has to be legislated. We’ll only see widespread change across society when government leads the way. That’s why The Environment Act 2021 has been largely hailed as a “world-leading” piece of legislation. 

It seeks to improve the natural environment by improving air and water quality, boosting recycling, preventing waste, and promoting the protection of species. The Environment Act became law in November 2021, setting the tone for the future of environmental law in the UK. Natural England has described it as a “turning point for nature”.  

A key part of this legislation was biodiversity net gain (BNG), a process where developments are required to consider the impact of their work on surrounding biodiversity. For a net gain to be achieved, the biodiversity and local ecosystem should be left in a better state than it was before. 

Read on to find out more about The Environment Act 2021 and how it will be introducing a 10% biodiversity net gain requirement for future developments in England.

the environment act 2021

What is The Environment Act 2021?

The Environment Bill was passed in 2021, and BNG will soon become legally binding through the forthcoming Environment Act in 2023.

George Eustice, the Environment Secretary, has praised the Act as being the “most ambitious environmental programme of any country on earth”. The focus of the act is to put the environment at the heart of the economy, promoting sustainability, traceability, and biodiversity protection. The Act became law during COP26 in Glasgow.

 The Environment Act 2021 has led to the creation of the ‘Office for Environmental Protection’ (OEP). This independent office is responsible for holding the government and public body organisations to account for the obligations set out by the Act and future legislation. 

Some of the headline measures include protecting rainforests and reducing the impact of sewage discharges from storm overflows. The Environment Act 2021 aims to halt the decline in species by the end of the decade by preventing deforestation and requiring new developments to create and improve surrounding habitats. The act’s purpose is to address the issues of climate change and the loss of biodiversity by taking protective and proactive steps.

What The Environment Act 2021 is introducing:

The Environment Act 2021 delivers on several areas – including waste, recycling, clean air, water, and nature. While the Act is in-depth and covers 8 different parts, there are some stand-out environmental targets to the legislation. 

  • Halting the decline of nature by 2030
  • Environmental reporting and monitoring
  • Embedding environmental principles into domestic policymaking
  • The creation of the Office for Environmental Protection
  • Tackling waste crime
  • Requiring Local Authorities to tackle air quality issues
  • Focus on biodiversity net gain to ensure new developments deliver at least a 10% increase in surrounding biodiversity
  • Strengthen protection of woodland areas
  • Minimising damage water abstraction

The Environment Act 2021 sets out the government’s intentions post-Brexit on how they’ll guide environmental policy without being tied into EU programmes.


What the Act means for biodiversity net gain

The goal of The Environment Act 2021 is to create a circular economy that has the environment at its heart. It is working to promote sustainability throughout the economy, from more eco-friendly packaging to creating spaces for wildlife to flourish. This goal means that there’s a new approach to biodiversity net gain. 

While biodiversity net gain isn’t a new concept, and the National Planning Policy Framework requires a net gain approach which should be be achieved in a measurable way, there has never been a statutory requirement for it until now.  

Under The Environment Act 2021, developments and projects will now need to ensure there is at least a 10% net gain to biodiversity. This net gain will be measured through Metric 3.0.  

Every developer will be required to show how this net gain will be achieved through landscape planning and planting schemes. For this biodiversity net gain to be considered valid, it must be guaranteed for at least 30 years through the developer’s landscape management plans. 

mitigation hierarchy will need to be followed and demonstrated to avoid, minimise or compensate. If it is not possible to compensate on site, then offsetting will be required elsewhere through discussions with third parties such as land owners, public authorities landbanks or wildlife charities. 

There will also be the establishment of a national land register to show the biodiversity gain. Local authorities will play a role in creating this biodiversity net gain through so-called “local nature recovery strategies” across England. This will encourage habitat creation and enhancement in the right places. 

Conservation covenants will be a mechanism used to deliver this (this approach is in preparation by Defra and Natural England).

It is important to note that the metrics used are only concerned with habitats and do not take protected species in consideration. Other ecological legislation and policies will still apply following the introduction of the act.


What developers must do under The Environment Act 2021


If you’re a developer planning a project in England, you’ll need to understand how The Environment Act 2021 is changing every aspect of development. This legislation aims to make developers consider biodiversity net gains from the land acquisition, through to the design stage, and beyond. The biodiversity gain is intended to be worked into the designs instead of being retrospectively fitted into the plans.

Developers will primarily see a change in the planning stage. Local planning authorities will be expected to create new nature recovery strategies to meet the ambitious goals of The Environment Act 2021.

 Under the Act – and with amendments to the Town and Country Planning Act of 1990 – planning permission in England will only be granted with a biodiversity gain plan. At this stage, developers can take several different approaches to how they’ll achieve this biodiversity net gain. 

Developers can use their biodiversity plan to set out how they’ll minimise any adverse effects on surrounding habitats. They’ll also state how to identify and measure the biodiversity value on-site before and after development. The specifics that are required in the biodiversity plan will be set out by the local planning authority.

Developers must also incorporate Species Conservation Strategies and Protected Site Strategies to help in the delivery of better outcomes for nature. 

Are there any exceptions under The Environment Act 2021?

When the legislation is passed to bring the 10% biodiversity net gain into law, there will only be a few exceptions to it. The requirement will be part of every planning permission made for developments in England. 

Currently, the only exceptions are for planning permissions given under a development order for projects deemed exempt by the Secretary of State or part of urgent crown developments. It’s expected that these exemption categories will gradually expand over time through regulation changes made by the Secretary of State.  

In general, you can expect your development to fall under the 10% biodiversity net gain requirement, with the need for enhancements to be guaranteed and maintained for 30 years. Every developer must understand the implications of The Environment Act 2021 and how biodiversity net gain will impact the planning of future projects. 

How can Collington Winter assist?


Our team of ecologists and landscape architects have helped many developers over the years. We have provided policy guidance for biodiversity gain in England, which varies across each Local Planning Authority the country.  

There are three stages of using the assessment and we assist our clients during the very early stages of developments, including promotions and land purchases.  

We are more than happy to complete an informal initial assessment for sites of interests to help our clients understand the probable implications and costings of Biodiversity Net Gain from the offset.


1) Project Feasibility

  • Identifying implications for potential development projects.
  • Audits of land for biodiversity gain capacity at land acquisition stage.
  • Providing advice on options for delivery of biodiversity gain on and off-site or potential unit costs to the Local Planning Authorities.


2) Assessment and design

  • Baseline survey and habitat condition assessment – to provide data for the biodiversity metric (completed as part of a Preliminary Ecological Appraisal).
  • Detailed design-phase input: aim to retain highest valued ecological features, scope for habitat creation and enhancement .
  • Combining green infrastructure, SANG and habitat provision.
  • GIS expertise: managing metric data and supporting calculations.


3) Planning permission and delivery

  • Planning conditions: working with a project team (especially landscape teams) with the aim to provide feasible, proportionate and practical final designs and management.
  • Preparing long-term site management plans (or consult with Landscape Architects) and advising on future monitoring commitments.
  • If offsetting is required, we will liaise with local authorities, conservation organisations, and other third parties for agreeing the delivery of biodiversity gain. 

Please get in touch if you would like further information about the implications of the Environment Act 2021, Biodiversity Net Gain or Landscape Management Plans. We are happy to offer free CPD sessions on the Biodiversity Net Gain Principles and how we can help your projects achieve this.


If you would like to find out more about the services we provide, feel free to contact us using the details below.


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