The IES and the Association of Local Government Ecologists (ALGE) have responded to the Defra consultation on Improving the implementation of Biodiversity Net Gain for minor, medium and brownfield development.

Read the full response here.

Our response is based on the views of IES and ALGE members. Thank you to all of our members who supported this consultation response.

Our joint response with the ALGE follows close working on our joint BNG in Practice project, including:

• BNG in Practice Report (February 2025)
• BNG in Practice 2025 Event Series

Key points in our response include support for:

• The removal of the self-build and custom build exemption, and replacement with an exemption for a single dwelling house with a 0.1 hectare threshold
• Extending the de minimis to 50 square meters, accompanied by re-enforcement of the precautionary principle and implementation for larger sites
• Introducing a new exemption for development whose sole or primary objective is to conserve or enhance biodiversity
• Adapting the trading rules to allow the losses of any medium distinctiveness habitat to be compensated for with any other medium distinctiveness habitat, to provide greater flexibility in securing appropriate biodiversity outcomes (the right habitat in the right place)
• Simplifying the Small Sites Metric (SSM) to make it easier to apply correctly, and more straightforward for Local Planning Authorities to verify
• Exploration of a more active role for LPAs in stimulating and securing demand in the small sites BNG market
• The development of clear guidance for the SSM, and a digital tool, to enhance usability and accessibility
• Establishment of a competency framework for those doing BNG assessments, supported by action in the long term to grow both the professional ecology workforce and broader ecological literacy
• Relaxing the biodiversity gain hierarchy for small sites, placing off-site habitat enhancements with the same preference as onsite habitat enhancements
• Amending the Spatial Risk Multiplier to align with Local Nature Recovery Strategy and National Character Areas

Media contact
For further information please contact:

• Ellie Savage, IES Policy Officer (ellie@the-ies.org)
• IES Office +44 (0)20 3862 7484

Background

• The Institution of Environmental Sciences (the IES) is at the forefront of uniting the environmental sciences around a shared goal: to work with speed, vision and expertise to solve the world’s most pressing environmental challenges, together. As the global professional membership body for environmental scientists, we support a diverse network of professionals all over the world – and at every stage of their education and careers – to connect, develop, progress and inspire.
• The Association of Local Government Ecologists (ALGE) is the only organisation supporting professional officers with responsibility for, and an interest in, biodiversity and nature conservation in local authorities and National Parks across all four countries of the United Kingdom.