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Biodiversity Net Gain: What is Biodiversity Net Gain?

Biodiversity net gain refers to the process whereby a development (or project) considers the environmental impact in terms of biodiversity. It aims to ensure the biodiversity is left in a better state than before.

Biodiversity Net Gain (BNG) is being requested more frequently by Local planning authorities to inform a planning application. The aim is to demonstrate how the proposed development will be of benefit for biodiversity in a measurable manner. Utility providers, transport and other organisations are introducing Biodiversity Net Gain to internal policies to ensure any project will achieve a net gain. Some are even setting greater percentage gain targets than 10%.

Implementing BNG

Our team has strong experience completing biodiversity net gain and will provide guidance throughout the planning process, from the initial land purchase agreements to monitoring assessments.

what is biodiversity net gain

Our ecologists will complete a habitat classification assessment and the data is entered into a metric to measure changes to the natural environment, pre and post development. This metric is currently Defra Metric 3.0. Landscape planting plans and management plans are used to inform post development measures.

Calculating Biodiversity Net Gain

Metrics assign every habitat on a site a ‘biodiversity unit value’ according to its relative importance for biodiversity. This enables comparison between the existing value of a site and what will be delivered through development or management, post development. This may include an increase in natural habitats through retention and enhancement and/or creation, which goes over and above the environmental habitat originally on site.

Biodiversity Net Gain: The Environment Bill

The Environment Bill was passed this year, and BNG will soon become mandatory through the forthcoming Environment Act in 2023. However, the National Planning Policy Framework also requires net gain approach which should be be achieved in a measurable way.

Mandatory Biodiversity Net Gain

The Environment Act received Royal Assent in England in November 2021. It introduces a requirement to deliver biodiversity gain for developments in England. There is a two-year transition period before the net gain requirement becomes law (in autumn 2023).

The current national policy in England, The National Planning Policy Framework (NPPF) Paragraph 179 states:

“To protect and enhance biodiversity and geodiversity plans should:

b) … identify and pursue opportunities for securing measurable net gains for biodiversity.”

Paragraph 180 states:

“When determining planning applications, local planning authorities should apply the following principles: … opportunities to improve biodiversity in and around developments should be integrated as part of their design, especially where this can secure measurable net gains for biodiversity…”

Numerous Local Planning Authorities have been requesting the assessment for numerous years. Many have introduced or are currently amending local developers plans to ensure it is mandatory as a part of Local Policy.

The Act will require the key points:

  • Developers must deliver a minimum of 10% net gain through their schemes; this will be measured through a metric, currently Metric 3.0.
  • A developer will need to demonstrate how biodiversity gain will be delivered. This will be demonstrated through the production of detailed Landscape Planting Schemes, Landscape Management Plans and Monitoring assessment for on and/or off-site.
  • mitigation hierarchy is to be followed and demonstrated to avoid, minimise or compensate. If it is not possible to compensate on the development site, then offsetting will be required elsewhere. This will be done through discussions of third party land owners, the council, landbanks or wildlife charities.
  • Developers will have to guarantee the biodiversity gain i maintained for at least 30 years (as outlined in Landscape Management Plans).
  • New “local nature recovery strategies” will be prepared to geographically cover England by “responsible authorities”; 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).
  • A national register of land used for biodiversity gain will be established; this will involve setting up a new biodiversity credits market.
  • Metrics are only concerned with habitats and do not take protected species in consideration.
  • Other ecological legislation and policies still apply.

The aim is to get clients think about biodiversity during the initial land acquisition and design stages, and avoid retro-fitting the calculation once designs have been produced. Retrofitting will often lead to delays, unpredicted financial costs and difficulties with planning application determinations.

How can Collington Winter assist?

Our team of ecologists and landscape architects have helped numerous clients over the years, including policy guidance for biodiversity gain in England. It is important to note that this varies across each Local Planning Authority in 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 happy to complete an informal initial assessment for sites of interests. This helps our clients understand the probable implications and costings of Biodiversity Net Gain from the offset.

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.

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 creating or enhancing habitats.
  • Combining green infrastructure, SANG and habitat provision.
  • GIS expertise: managing metric data and supporting calculations.

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 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 schemes 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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