Biodiversity Net Gain Wales: Achieving BNG

Biodiversity Net Gain Wales

Biodiversity net gain (BNG) is an approach to development whereby developers consider the environmental impact a project will have in terms of biodiversity. It aims to ensure the biodiversity is left in a better state than before the development was completed for local people and future generations. This is done by avoiding loss of biodiversity and retaining natural habitats and ecological features.

BNG was requested as a result of studies such as the State of Nature Report UK that shows that the abundance of species studied in the UK has declined by 19%.

Biodiversity Net Gain is now being requested more frequently to inform planning applications. The aim is to demonstrate how the proposed development will be of benefit to biodiversity in a measurable manner. 

Following the passing of the Environment Bill, mandatory biodiversity gain for developments in Wales will be introduced through the forthcoming Environment Act in 2023. Following this, any development will be halted if it fails to meet the requirements. However, BNG is already required by the National Planning Policy Framework.

Due to relevant national legislation, biodiversity net gain is soon to become mandatory in Wales. The Welsh Government is now requesting biodiversity net gain and nature recovery to determine planning applications for planning permission.

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Biodiversity Net Gain aims


Biodiversity Net Gain (BNG) is a policy in the UK aimed at ensuring that new developments have a positive impact on biodiversity. The main aims of delivering Biodiversity Net Gain in the UK are:

  • Enhancing biodiversity: BNG aims to leave the natural environment in a measurably better state than it was before development takes place. This is achieved by ensuring that the biodiversity value of a site after development is higher than it was before. In cases where a development affects biodiversity, developers must ensure the provision of additional suitable natural habitats and ecological features, surpassing the impacted area by at least 10% compared to the initial baseline.
  • No net loss: BNG aims to ensure that there is no net loss of biodiversity as a result of development activities. This means that any loss of biodiversity due to construction or other development activities should be compensated for elsewhere.
  • Improving ecosystem services: BNG seeks to enhance the provision of ecosystem services, such as pollination, water purification, and climate regulation, which are crucial for human well-being.
  • Habitat creation and restoration: BNG encourages the creation and restoration of habitats, including wetlands, woodlands, grasslands, and other ecosystems that support a diverse range of species.
  • Connectivity and green infrastructure: BNG promotes the creation of green corridors and connectivity between habitats, allowing wildlife to move freely and ensuring genetic diversity within populations.
  • Sustainable development: Biodiversity Net Gain aims to integrate biodiversity conservation with economic development. It emphasises the importance of sustainable land use planning and construction practices.
  • Adaptive management: BNG promotes the concept of adaptive management, which involves monitoring the biodiversity outcomes of a development and making adjustments as needed to achieve the desired net gain.
  • Compliance with legal requirements: BNG aligns with existing legal requirements related to biodiversity conservation in the UK, including the Wildlife and Countryside Act and the Conservation of Habitats and Species Regulations. The Environment Act 2021 will make BNG a legal planning requirement from November 2023.
  • Public engagement and education: It encourages public engagement and education about biodiversity conservation, helping to raise awareness and foster a culture of environmental stewardship.
  • Long-term Sustainability: BNG aims for the long-term sustainability of biodiversity gains, ensuring that they are maintained and managed effectively over time.

Biodiversity Net Gain Principles

There are ten crucial good practice principles of biodiversity net gain. These should help to achieve BNG if they are followed accordingly. The mandatory biodiversity net gain principles include the following:

  • Utilise the mitigation hierarchy to minimise the impact on biodiversity
  • Eliminate any negative impacts on biodiversity
  • Communicate each BNG outcome with complete transparency
  • Cover all areas of sustainability, including societal and economic factors
  • Involve any pre-development and post-development stakeholders in creating mandatory net gain solutions
  • Focus on producing long-term natural net benefit for biodiversity. This will ensure a development leaves biodiversity in a better state than it was before
  • Understand the variable factors and potential risks in order to achieve biodiversity and deliver net gain
  • Offer nature conservation that exceeds the stated BNG requirements
  • Determine a suitable method in order to secure measurable biodiversity net gains
  • Ensure the best possible results from biodiversity net gain

Biodiversity metric

The biodiversity metric serves as a tool to gauge how a development or alteration in land management will impact the biodiversity value of a site. This includes activities like constructing houses, establishing woodlands, or cultivating wildflower meadows.

This metric enables you to:

  • Evaluate the biodiversity unit worth of a specific land area.
  • Provide a consistent means of showcasing biodiversity gains or losses.
  • Quantify and acknowledge direct effects on biodiversity.
  • Compare different proposals for a site, whether they involve on-site or off-site habitat creation or enhancement.

It aids in the process of designing, planning, and making informed land management decisions that prioritise biodiversity. The metric computes values in terms of ‘biodiversity units’, which are determined by considering factors like habitat size, quality, and location.

Our team of ecologists and landscape architects have helped numerous clients over the years. Our clients have ranged from minor developments to major applications. We have assisted with matters regarding policy guidance for biodiversity net gain in Wales.

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

Biodiversity credits

Most local planning authorities in Wales will want developers to ensure that BNG is achieved on-site. In some circumstances, this cannot be achieved, and it is simply not possible. However, this does not mean that the local planning authorities will automatically refuse a planning application.

Instead, the local planning authority may grant planning consent if developers are able to deliver sufficient biodiversity net gain using offsite biodiversity habitat enhancement.

Developers may be given the option of purchasing biodiversity credits through funding schemes that will generate the equivalent number of units in other areas.

The biodiversity net gain credits purchased will then be invested into habitat creation and enhancement.

Natural England is currently supporting the design of the credits scheme by developing payment structures and a BNG credit investment pipeline to fund habitat provision.

How Can Collington Winter Assist with BNG in Wales?

Collington Winter Environmental are experts in BNG planning and have helped numerous Wales-based clients over the years. It is important to note that this varies across each local planning authority in the country. Completing net gain for biodiversity through development is something that we are qualified and experienced in.

We assist all types of developers in achieving BNG to ensure planning permission is granted in Wales.

We are determined to offer you the support you need in order to reach the required mandatory biodiversity bracket. If you would like to find out more about biodiversity net gain, Wales, feel free to contact us using the details below.

We can assist with biodiversity net gain by providing: 

Please get in touch if you would like further information about BNG. We can also develop land management plans. We are happy to offer free CPD sessions on the BNG principles and how we can help your schemes achieve this.

Our Ecology Director, Olivia Collington, holds a Natural England license. If you would like to find out more about the ecosystem services we provide, feel free to contact us using the details below.

Contact Us

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Future Business Centre, Cambridge Campus, Kings Hedges Road, Cambridge, CB4 2HY


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