What is Biodiversity Net Gain?

DEVELOPMENT THAT LEAVES BIODIVERSITY IN A BETTER STATE THAN BEFORE.

In terms of planning policy Biodiversity Net Gain seeks to reverse natures' decline across England (and beyond). It places a requirement on developers to increase biodiversity levels in measurable units for a defined area of land, to secure planning permission.

Most Local Planning Authorities already request development to demonstrate positive outcomes for nature, however the new Environment Bill proposes making Biodiversity Net Gain of 10% mandatory for nearly all new development.

Calculating Biodiversity

A Biodiversity Net Gain Assessment compares the pre-development baseline conditions to post development plans. It uses a spreadsheet calculator known as the Biodiversity Metric to convert habitats into biodiversity units which have a monetary value ascribed to them.

Assessment Process:

1. Undertake field survey to collect pre-development habitat information 
2. Desktop study to:
   1. Review proposed development landscape plans to gather post-development habitat information
   2. Set strategic context using relevant local, regional & national plans
3. Review any offsite compensation (or Gain) site plans for habitat creation/enhancement information
4. Use pre & post development information to run the Biodiversity Metric which will convert habitats into Biodiversity units
5. The Biodiversity Metric output will be either a gain or loss for biodiversity expressed as a percentage

Should a biodiversity loss or a too low gain be calculated then consultation to refine the landscape plans will be required until an acceptable level of Net Gain can be achieved. 

If this isn't possible then a compensatory payment may be agreed and which is commensurate with the value of the biodiversity units lost. It's worth noting that although this has not been set yet costs attributed so far are between £9,000 to £15,000 per unit. Most are applying an average of £11,000 per biodiversity unit.

Net Gain should be achieved on a permanent basis, with the requirement for compensatory habitats to be actively managed for 30 years.