Design South East hosted a Kent Design workshop entitled Biodiversity Net Gain in Practice in Sevenoaks to discuss how biodiversity net gain (BNG) is working one year on from the introduction of the policy requirement for all new developments to deliver a BNG of 10%. The three-hour session was designed to help attendees navigate the common challenges faced when incorporating the BNG metric onto sites of varying scales. This was framed through a series of case studies within the South East region.
The afternoon was structured through the lens of Local Authority perspective, followed by three case study presentations, summarised below.
Four things to look out for as BNG enters its 2nd year
David Scully (Landscape and Biodiversity Officer, Tunbridge Wells Borough Council)
The introductory presentation from David Scully explored four main challenges to achieving BNG: Additionality, Local Nature Recovery Strategies, Irreplaceable Habitats and the nuances around habitat classification and condition assessment of grassland. David spoke knowledgeably about the complexities of these components within the metric, and consequently the challenges of application of the metric in practice.
Case study: South East Faversham
Eleanor Trenfield (Director, EDLA), David Smith (HR and Business Systems Director, EPR) & Peter Lacey (Project Manager, Duchy of Cornwall)
The South East Faversham case study drew upon the principles of ‘bigger, better, more joined up’ (The Lawton Review), and demonstrated the merit of creating multifunctional, useable space, and incorporating nature through the design of productive corridors for growing. It highlighted the importance of creating a clear narrative and themes for the wider project, to truly embed the landscape within the project. The message was that designers should not become so fixated on the numbers that it comes at the expense of creating useable green space, and that biodiversity must not be considered separately to creating landscapes for people.
Case study: Letchworth Garden City
Peter Neal (Landscape Consultant, Peter Neal Consulting Ltd)
The Letchworth Garden City framework reinforced the significance of getting the principles for development right early on, and integrating this into the decision-making process. Within new towns and garden suburbs, we have the opportunity to use the green infrastructure and landscape to structure our places and create a synthesis between garden and city. On a project of this scale, Peter emphasised the importance of formulating a modern design approach that is fit for the 21st Century, where climate resilience and richer ecology are drivers of the Garden City extension, as well as illustrating how to showcase the character of the site through the landscape, and where to look for clues, such as drawing on National Character Area profiles.
The Small Sites Metric (SSM)
Deborah Nagan (Director, Deb Nagan Studio)
We concluded the session by moving onto the application of the BNG small sites metric, which applies to sites which are under 1 hectare of land, and/ or less than 9 dwellings. The emphasis of this presentation was on the Principle 7 of the biodiversity metric principles:; the need for habitat interventions to be realistic and deliverable within a relevant project timeframe and Principle 8:; for creative and enhanced habitats to be practical and reasonable, local to any impact and to deliver strategically important outcomes for nature conservation. On these small sites, biodiversity is about supporting climate resilience through smaller-scale interventions, such as flood mitigation, and small developers must embed this into their strategy for the site, once again shining a light on the importance of narrative and placemaking.
Four key takeaways from the session:
- BNG as an approach to development must make sure that natural habitats for wildlife are considered holistically with landscapes for people. The relationship between people and nature is perceived as a challenge, which has been created in part by the constraints of the metric, but we must not forget that the core principles of BNG are elements that we should be seeking to achieve anyway; clear design objectives, variety in the landscape, and understanding how solutions work in their context.
- While BNG is a metric, the process of applying it should be done through the exploration of strong narratives and key design themes, which should be drawn up at the start of the project and should run throughout.
- The process for design when it comes to BNG should start with landscape character, such as drawing on National Character Area profiles and Statements of Environmental Opportunity, which can indicate sensitivities and opportunities that can be drawn upon. This bears just as much relevance to small sites, too, and if done well, BNG can help to enhance place and identity, to become a unique selling point for a proposal.
- There is no substitute for knowing the site, and this knowledge can only be fully realised with an effective design team made up of different disciplines, who have a dedication to enhancing what already exists. This includes drawing on the knowledge of the relevant local authority.
It was clear from the session that the complexities of the BNG metric are nuanced, and it is only by looking at how it can tangibly be applied to different sites and at different scales, that we can understand how this metric can provide positive outcomes for wildlife, people and place.
A huge thank you to all of our speakers, who presented a rich array of case studies and shone a constructive light on the opportunities and constraints, and thanks to all those who attended for your enthusiasm and insights.
(Image credits: David Cliff)
