24 Feb, 2023
Wild flowers

On 21st February the Government published the results of its 2022 consultation on the implementation of Biodiversity Net Gain (BNG) within planning policy and legislation. We hope you find this leaflet useful as we continue to navigate the process with you and work with you in your future and current applications. Read this article in full our Download our briefing note instead.

We are still awaiting the Government’s responses to the consultation on the DEFRA Metric however and as soon as we know more, we will let you know. What we do know is that the next version of the Metric is due to be ratified under the Secretary of State and be set for a period of 3-5 years giving us the much needed clarity and stability on assessing sites and the impacts of a scheme.

Key dates

  • Confirmation of Nov 2023 for full implementation of the Environment Act and its requirements for mandatory net gain of 10% for all development schemes. An extended transition period for small sites is proposed until April 2024.
  • New guidance, in line with this consultation briefing is to be published by the Government. No date was given, expected to be in time for full implementation of Environment Act in Nov 2023.
  • Similarly, updates to the Biodiversity Gain Plan and Habitat Management and Monitoring Plan templates and guidance is to be published, however no date was provided for this.
  • A consultation on the DEFRA BIA metric itself concluded in September 2022, with results and a new version of the metric expected in approximately Summer 2023.

Biodiversity Gain Plans

Schemes will have to provide a Biodiversity Gain Plan (BGP) in addition to and supported by the DEFRA Metric. This document will set out/detail the onsite and offsite measures implemented for the scheme to achieve net gain. An amended template for this is to be published in due course. Core information to be included in the BGP is:

  • The pre-development biodiversity value;
  • The proposed approach to enhancing biodiversity on-site; and
  • Any proposed off-site biodiversity enhancements (including the use of statutory credits) that have been planned or arranged for the development

Whilst a summary BNG statement and metric is to be provided at application stage, the full BGP is to be provided prior to commencement of the development.


Exemptions from mandatory BNG:

Whilst all developments will still be expected to provide biodiversity enhancements in line with planning policy a number of new exemptions from requiring mandatory net gain by way of a calculation are proposed:

  • Development impacting habitat of an area below a ‘de minimis’ threshold of 25 metres squared, or 5m for linear habitats such as hedgerows;
  • Householder applications and small scale self build projects;
  • Biodiversity gain sites (where habitats are being enhanced solely for wildlife).

The Environment Act will already allow exemptions for:

  • Temporary Impacts, restored within 2 years;
  • Development on sealed surfaces.

Mandatory BNG and different types of development

Outline and Phased DevelopmentsOutline planning applications will be required to submit biodiversity gain information at application stage. Summary information on how biodiversity gain is achieved on a phase by phase basis will be required at application stage, with a full biodiversity gain plan submitted prior to commencement of each individual phase.

Small sites: A new version of the small sites metric to be released. Longer transition time for implementation of BNG on small sites until April 2024

How BNG will work: Credits: Banks, Price etc?

BNG Credits, Units, Banking:

It is proposed that any landowners or managers, including local planning authorities are to be able to create or enhance habitat for the purpose of selling biodiversity units, provided that they are able to meet the requirements of the policy.

Developers will be allowed to sell excess biodiversity units through the proposed national register, operated by Natural England, and this is to be opened by November 2023. A registration fee of between £100-1000 is currently proposed.

Natural England will also sell credits until the private market has established. Guidance on price of these units will be published in summer 2023, with price reviews undertaken every 6 months.

Cost of Units:

Full guidance on costing of units is to published in summer 2023 however it is expected that the price of “private” units should be determined by negotiations between the buyer and seller and are likely to vary by habitat type and location. Sellers must ensure that the price is sufficient to cover the costs of creating or enhancing the habitat, any necessary monitoring, and maintaining it for a minimum of 30 years.

Additionality/mitigation stacking:

All five of the governments proposals on additionality or “stacking” of onsite mitigations will be implemented. In brief this will allow for inclusion of net gain from measures such as eg SUDs, nutrient mitigation, mitigation and compensation measures for protected species (with certain caveats) and mitigation for nearby statutory protected sites. Full guidance on this is to be published at a later date.


RammSanderson have a dedicated BIA team and the company have sought to positon ourselves at the forefront investing heavily in UKHABAS training via CIEEM and DEFRA. Complementary to this we have ensured as a company we have trained staff capable of undertaking the river aspect of BIA referred to as MORPH. The team have  depth of experience working with a wide range of clients from varying sectors and all scales of projects. We work closely with our clients from conception to manage the BIA requirements for planning. We also have a habitat team who deliver BNG on sites within our clients portfolios and can facilitate conversations with land owners to seek offsetting schemes.

To find out more get in touch with one of our team on 0115 930 2493