Biodiversity Net Gain Somerset: Understanding BNG

Somerset is home to rich biodiversity and diverse landscapes, including ancient woodlands, species-rich grasslands, and protected wetlands. These environments support rare and threatened species, making their protection and enhancement a key part of the planning system.

To support these natural assets, developers are encouraged to work with the Somerset Local Nature Recovery Strategy (LNRS) in mind. This ensures developments deliver measurable biodiversity improvements that align with regional priorities, such as enhancing hedgerows, reconnecting wildlife corridors, and protecting habitats for key species like water voles, skylarks, and great crested newts.

In situations where on-site biodiversity enhancement is not feasible, whether it be due to space constraints or existing land use, Somerset County Council allows for the use of off-site biodiversity units. These can be purchased through recognised habitat banks or biodiversity offset providers, ensuring gains are delivered within ecologically relevant locations.

Popular off-site interventions include woodland creation, peatland and wetland restoration, and the rewilding of degraded farmland. All enhancements must be maintained for at least 30 years and be measurable and monitored over time to make certain they continue to deliver BNG units.

BNG applies to a broad range of developments, including:

• Housing developments with 10+ homes or sites larger than 0.5 hectares.
• Commercial or industrial building with over 1,000m² floorspace.
• Smaller projects, which may still need to meet BNG criteria depending on local authority guidance.

The goal of BNG is not simply to offset the harm caused by development, but to embed nature-positive outcomes into long-term planning. This involves a structured process of site analysis, mitigation, and habitat improvement – creating net positive contributions to biodiversity rather than just minimising damage.

To meet BNG requirements, our ecological consultants work in collaboration with developers to use Natural England Biodiversity Metric tools, allowing them to quantify baseline habitat conditions and predict gains after the development is completed. Monitoring, management plans, and ongoing stewardship are also required to ensure promised gains are maintained into the future.

There are ten guiding principles that underpin successful BNG planning:

1. Follow the mitigation hierarchy to reduce biodiversity loss.
2. Avoid impacting irreplaceable habitats.
3. Work collaboratively and transparently with stakeholders.
4. Promote sustainability across ecological, social, and economic dimensions.
5. Engage with specialists and local communities throughout the project lifecycle.
6. Deliver measurable, long-term improvements to biodiversity.
7. Account for risks and changes over time.
8. Aim to exceed the 10% requirements when possible.
9. Use the latest biodiversity metric tools/
10. Ensure projects provide lasting value for nature.

At Collington Winter Environmental, our team of ecologists and environmental consultants works with developers and land managers across Somerset to ensure BNG compliance. We assess habitats using the latest statutory biodiversity metrics and draft detailed biodiversity net gain plans to guide developers through this sometimes tricky part of their development journey.

With the certification of Natural England licences, our experts are familiar with local planning authorities’ policies and requirements, and we offer practical, tailored advice to support an application with your site habitats in mind.

Whether you’re managing a housing project in Taunton, a rural development in Frome, or a commercial expansion near Yeovil, our consultants bring local insight and national policy expertise to help you meet your obligations while enhancing the natural environment.

To learn more or speak to an ecological consultant about how we can help your development site achieve BNG, contact us at info@collingtonwinter.co.uk or fill out the contact form below.