What is Biodiversity Net Gain?

Biodiversity Net Gain (BNG) is achieved when development leaves biodiversity in a better state than before. The revised National Planning Policy Framework (2019) states that local planning authorities (LPAs) in England should identify and pursue opportunities for securing measurable net gains for biodiversity. Whilst BNG is not a new concept, the Environment Act (2021) has introduced a mandatory requirement for 10% BNG on most new developments.

Who Does It Apply To?

The achievement of 10% net gain is a mandatory requirement for major developments where planning permission is required. Smaller development sites (less than 1ha in area) will be subject to a more simplified requirement, due to become mandatory on 2nd April 2024. Some LPAs also have their own local policies in place that require a higher minimum net gain, so local knowledge is essential. BNG is expected to become mandatory for Nationally Significant Infrastructure Projects (NSIPs) in 2025.

Biodiversity Impact Assessment

A Biodiversity Impact Assessment (BIA) involves calculating biodiversity units pre- and post-development, and then calculating the percentage change, using the Statutory Biodiversity Metric. The key steps to an assessment are as follows:

  1. Conduct a pre-development field survey to assess the conditions of baseline habitats (EMEC can undertake this as part of the usual Preliminary Ecological Appraisal to make the process more efficient).
  2. Review landscape and planting proposals to assess post-development habitats.
  3. Use the Biodiversity Metric to calculate pre- and post-development biodiversity units and the percentage change. EMEC uses the Natural England Statutory Metric.
  4. If there is a shortfall in the target BNG (i.e. less than 10%), EMEC can provide pragmatic recommendations for achieving an increase in post-development biodiversity units. Consideration can be given to on-site and off-site habitat creation and enhancement solutions, or the purchase of statutory credits as a last resort. EMEC uses local knowledge to secure the best results for local wildlife, maximising the number of biodiversity units that can be achieved.
  5. Once a final proposal to achieve BNG is reached, EMEC is able to produce a Habitat Management and Monitoring Plan (HMMP), as required by planning. This document is needed to secure appropriate habitat management for at least 30 years.

How Can EMEC Help?

  • EMEC can conduct a Biodiversity Impact Assessment and advise developers how best to achieve their BNG target.
  • EMEC can discuss options for increasing post-development biodiversity units through local off-site habitat creation.
  • EMEC’s land management team can enhance existing habitats and create new habitats with high biodiversity value.
  • EMEC can prepare long-term ecological management and monitoring plans for a site. EMEC’s land management team can deliver on those plans in the long-term and satisfy all long-term management and reporting requirements.
  • EMEC can project manage the entire BNG process through its whole service provision.