Understanding Biodiversity 3.0

Biodiversity Net Gain is a key consideration for developers. All new developments must leave the environment in a better condition than it was before. In fact, the Environmental Bill currently sets the compulsory net gain at a 10% increase, secured for at least 30 years.

This requires developers to deliver an increase in appropriate natural habitat and ecological features in a way that helps to restore any biodiversity losses caused by construction. Although this is an incredibly important commitment, to date, there has been no standard definition for this process, or a method to evaluate or measure net gain.

This summer, Natural England finally unveiled a number of tools to help developers measure biodiversity net gain, to ensure all new developments are ‘nature positive’. These new metrics include the Biodiversity Metric 3.0, the Small Sites Metric (SSM), and the Environmental Benefits from Nature Tool (EBNT).

 The Biodiversity Metric 3.0

The Biodiversity Metric 3.0 provides a way of measuring and accounting for nature losses and gains resulting from development or changes in land management. This tool updates and replaces the beta Biodiversity Metric 2.0 and is the culmination of more than 14-years’ work to develop a practical metric to measure gains and losses of biodiversity in England.

The tool can be used to:

  • Assess or audit the biodiversity unit value of an area of land
  • Calculate the losses and gains in biodiversity unit value resulting from changes or actions which affect biodiversity, such as from development or changing the conservation management of a land holding
  • Predict the likely effectiveness of creating new or enhancing existing habitats
  • Compare different plan and project proposals for a site allowing more objective assessments of alternative approaches to be made

The metric can be used throughout all stages of a project, from site selection and options assessment through to detailed design. The earlier it is applied the greater the opportunities for optimising the project design to deliver net gains, determining whether the project is suitable for application of this metric, and testing whether the outcomes are as expected.

The Biodiversity Metric 3.0 will become the industry standard metric for all on-land and intertidal development types in England, and when the landmark new Environment Bill is delivered, the metric will become a legal requirement for ecological consultants, developers, local planning authorities, and land owners.

 The Small Sites Metric (SSM)

The Small Sites Metric (SSM) is a beta version of the Biodiversity Metric 3.0, designed to simplify the process of calculating biodiversity net gain on smaller development sites.

Small development sites are defined by Natural England as ‘small sites where both of the following criteria are met’:

  1. Development sites where:
  • For residential developments the number of dwellings to be provided is between one and nine inclusive on a site having an area of less than one hectare
  • Where the number of dwellings to be provided is not known, but the site area is less than 0.5 hectares
  • For all other development types where the site area is less than 0.5 hectares or less than 5,000sqm
  1. Where there is no priority habitat present within the development area (excluding hedgerows and arable margins).

Published in beta format, the Small Sites Metric will seek feedback from users prior to a further update in the future.

The Environmental Benefits from Nature Tool (EBNT)

The Environmental Benefits from Nature Tool (EBNT) provides developers, planners and other interested stakeholders with a way of exploring the benefits that biodiversity net gain brings to people and nature, such as improvements to water quality, flood management services and carbon storage.

Designed to work alongside the Biodiversity Metric 3.0, the Environmental Benefits from Nature Tool uses a habitat-based approach to provide a common and consistent means of considering the direct impact of land use change.

The Environmental Benefits from Nature Tool has been developed by Natural England and the University of Oxford in partnership with Defra, the Forestry Commission and the Environment Agency to support Government’s 25 Year Environment Plan commitment to expand net gain approaches to include wider Natural Capital benefits such as flood protection, recreation and improved water and air quality.

Although designed to work with the Biodiversity Metric 3.0, it is a voluntary tool that is not required to meet the biodiversity net gain provisions set out in the Environment Bill for development in England.

Using the tools in practice

When the Environment Bill becomes law, demonstrating biodiversity net gain will become a vital part of securing planning consent in England. Local planning authorities will require all new planning applications to include biodiversity net gain calculations to prove there will be biodiversity improvements. This proof should include:

  • Written documentation and clear maps showing the assessment of net gain for biodiversity
  • The level of net gain for biodiversity currently acceptable in the local planning authority area
  • The measures to achieve 10% net gain for biodiversity onsite or alternative compensation measures
  • Financial support for 30 years positive biodiversity management (through a s106 or similar agreement)
  • A Design & Access Statement explaining the derived Biodiversity Net Gain
  • Proof that an ecological consultant has advised on the mitigation hierarchy, avoidance of damage, and a net gain assessment or compensatory off-site solutions.

Appointing an ecological consultant at the start of planning will simplify this process significantly. They will conduct a series of surveys and assessments, and work closely with the designers to ensure that the best possible solutions to achieve Biodiversity Net Gain are considered from the very start.

For more information about biodiversity net gain and how the new Biodiversity 3.0 tools can be utilised in your project, get in touch with us on 01225 459564 or

Get in touch

To discuss your project requirements, please contact our experienced team