News

On 8^th July 2024 a roundtable discussion was held in Canterbury with public, private and charity sector natural environment professionals working in Kent and Medway. The purpose was to reflect on how biodiversity net gain (BNG) is working in practice and how effective it is for delivering positive outcomes for nature and people. The roundtable concluded with a set of recommendations for improving the BNG Metric guidance and its application on development sites, which would help to maximise the potential of this important tool. The roundtable was hosted by Design South East and EDLA Landscape Architects. 

The BNG Metric is largely fit for purpose and there are best practice examples of it in use. However, applying the Metric without considering other important landscape, tree and ecology considerations can lead to inappropriate outcomes for ecology and people, and reduced ambition in landscape design. In some development projects, meeting the 10% BNG threshold has meant restricting people from habitats, reducing opportunities for recreation and nature connection, contrary to best practice in landscape design. Local Plans and development industry practices have not all caught up with BNG requirements, sometimes leading to viability challenges and sub-optimal outcomes for BNG.  

Our key recommendations (provided below) focus on: 

1. Strengthening the BNG user guidance and supporting DEFRA guidance to add greater weight to ensuring good design, access to nature and public open space provision on development sites alongside BNG; and, 

2. Improving the application of the BNG Metric in practice as part of design-led and strategic planning approaches.  

Key recommendations for improving the BNG Metric and working practices 

• The application of the BNG Metric in practice needs to be part of a multi-disciplinary, sensitive, design-led approach. Practitioners should avoid a ‘design by spreadsheet’ approach where achieving the metric is prioritised over best practice masterplanning and landscape design principles. Wording in the BNG guidance should be strengthened to reflect his.  

• The need for appropriate, realistic and deliverable habitats, not just those that score highly, is made clear in the BNG guidance. However, this key aspect of BNG is not always consistently applied by applicants and enforced by local authorities. Ecologists, developers and local authority officers may need upskilling and the wording in the metric could be strengthened to reinforce this.  

• BNG needs to be integrated into early decision-making on strategic planning and development, including Local Plan site allocations and development feasibility analyses. As one attendee put it, ‘A landscape-led approach is the only way to deliver BNG’.  

• More funding should be provided for local authority landscape and biodiversity officers. Many councils have no in-house BNG expertise and can’t enforce the proper use of the Metric or engage with it proactively. Proper resourcing is essential to ensure positive outcomes and appropriate monitoring of implementation. 

• In places that are particularly low in biodiversity, a much higher level of net gain beyond 10% could be targeted. Where appropriate, local authorities should consider increasing the percentage of BNG requirement through local plan policy and site allocations, informed by appropriate evidence.  

• Guidance on climate change resilience and adaptation needs to be integrated with the Metric to ensure habitats are resilient into the future. The Metric should incentivise retaining and planting a broad mix of native and non-native trees appropriate to the location and landscape character, chosen on the basis of the “Right Tree for the Right Place” principle. Currently, non-native tree species are disincentivised in the Metric despite their potential role in enhancing climate resilience.  

• The Metric should be more inclusive of a range of habitat creation approaches, including rewilding and natural regeneration. 

• The Metric could review how the weighting is working in practice to disincentivise the creation of large areas of single habitat type to maximise scores. A mix of habitat types will often offer additional benefits for wildlife and people and infer greater resilience.  

• In ecological terms, the 30-year timespan of BNG is actually quite short and can lead to unintended consequences, such as disincentivising slow growing trees or woodland habitats in favour of pioneer species and habitats that are quick to establish like grassland. In some situations, a longer timespan of 50-100 years would be more appropriate. Development projects need to consider how habitats will change or be managed beyond 30 years, particularly facilitating the growth and maturation of trees.  

• BNG is new and we are all still learning. Natural England should provide further guidance, host CPD events and hold Q&A sessions with built and natural environment professionals so that the nuances of the legislation and Metric can be properly understood.  

• The Metric and guidance could be improved for various aspects of arboriculture: 
  • The definition of veteran trees within the BNG legislation needs to be amended to avoid capturing all trees with deadwood or a cavity regardless of size and age.  
  • There is a need for the Tree Helper to be adapted to provide a clear differentiation between existing and proposed trees. 
  • A clearer definition should be made within the BNG Guidance on what constitutes an urban and a rural tree, and why one has a higher attribution to the other.  
  • Amend the Metric to include tree planting within hedgerows, which is currently not accounted for. 

Roundtable attendees 

Eleanor Trenfield	Director	EDLA Landscape Architect
Donald Roberts	Director	EDLA Landscape Architect
Ross O’Ceallaigh	Learning Programme Manager	Design South East
Nicky Britton-Williams	Biodiversity Net Gain Officer	Kent Council Council
Robyn Wickman	NbS Project Development Officer	Kent Wildlife Trust
Samual Durham	Director, Ecology	Lloyd Bore
Andrew Cox	Director, Landscape	Lloyd Bore
Paul Bratton	Senior Landscape Officer	Medway Council
Mike Sankus	Tree Officer	Medway Council
David Smith	Director	EPR
Sylvia Harmer	Ecologist	Adonis Blue Environmental
Annie Brown	Landscape Officer	Ashford Borough Council
Helen Lucking	Owner	Corylus Ecology
Brian Hawtin	Associate Landscape Architect	Huskisson Brown