A spring forward to balancing development and biodiversity: the implementation of the mandatory biodiversity net gain and principles of best practice 

The government’s spring statement released on 13 March 2019 announced that the government will “use the forthcoming Environment Bill to mandate biodiversity net gain for development in England ensuring that the delivery of much needed infrastructure and housing is not at the expense of vital biodiversity.”

At a time when the government is coming under increasing pressure to build more and more homes to support a growing population and a fragile economy via Affordable Housing, it is important that there is also an opportunity to make the environment synonymous to the planning regime and a framework to be created which promotes sustainable growth. 

The Biodiversity Net Gain

Biodiversity Net Gain is defined as “development that leaves biodiversity in a better state than before, and an approach where developers work with local governments, wildlife groups, landowners and other stakeholders in order to support their priorities for nature conservation”. It is a policy framework for development projects and an approach which is proposed to be integrated into the existing planning and development process so that planning decisions will be taken in accordance with what the development can do for the environment.

Under the framework, developers will be required to ensure habitats for wildlife are enhanced and left in a measurably better state than they were pre-development. They must assess the type of habitat and its condition before submitting plans, and then demonstrate how they are improving biodiversity – such as through the creation of green corridors, planting more trees, or forming local nature spaces.

The Department for Environment, Food and Rural Affairs (DERA) have been keen to comment on this framework and call for “green improvements on site to be encouraged” and in the rare circumstances where they are not possible, developers will need to pay a levy for habitat creation or improvement elsewhere” (https://deframedia.blog.gov.uk/2019/03/13/government-to-mandate-biodiversity-net-gain/)

Good practice principles

To achieve biodiversity net gain, developers will be required to follow a series of good practice principles:

  • Mitigation – do everything possible to first avoid and then minimise impacts on biodiversity.
  • Avoid losing biodiversity that cannot be offset elsewhere – avoid impacts on irreplaceable biodiversity as these impacts cannot be offset
  • Be inclusive and equitable – engage stakeholders and involve them in designing, implementing, monitoring and evaluating the approach to net gain. Achieve net gain in partnership with stakeholders
  • Address risk – mitigate difficulty, uncertainty and other risks and apply well-accepted ways to add contingency when calculating biodiversity losses and gains in order to account for any remaining risks, as well as compensate for the time between the losses occurring and the gains being fully realised.
  • Make a measurable net gain contribution – achieve a measurable, overall gain for biodiversity and the services ecosystems provide while directly contributing towards nature conservation priorities.
  • Achieve the best outcomes for biodiversity by:
  • Delivering compensation that is ecologically equivalent in type, amount and condition and that accounts for the location and timing of biodiversity losses
  • Compensating for losses of one type of biodiversity by providing a different type that delivers greater benefits for nature conservation.
  • Achieving net gain locally to the development while contributing towards nature conservation priorities at local, regional or national levels
  • Enhancing existing or creating new habitat
  • Enhancing ecological connectivity by creating joined areas for biodiversity
  • Be transparent and communicate with shareholders and the local planning authority

Scenarios for residential developers

The following scenarios illustrate the broad mechanisms through which a residential development could achieve biodiversity net gain under the policy proposals:

  • Scenario A: the developer is able to avoid harm, mitigate and enhance on site
  • Scenario B: the developer is unable to avoid, mitigate and compensate all impacts on site, but is able to secure local compensatory habitat creation
  • Scenario C: the developer is unable to avoid, mitigate and compensate on site and unable to find local compensatory habitat to invest in. A tariff is therefore used to fund cost-effective habitat creation projects according to local and national conservation and natural capital priorities.

Framework feedback 

Support for this framework is already gaining momentum. The Environment Secretary Michael Gove has said that “mandating biodiversity net gain will ensure wildlife thrives at the same time as addressing the need to build new homes. Whether it’s through planting more trees or creating green corridors, developers will now be required to place the environment at the heart of new developments”.

Gove said the new approach will “not only improve habitats for wildlife and create healthier places to live and work, but is central in our ambition to leave the environment in a better state for future generations”.

Natural England has also welcomed the announcement, saying it looked “forward to working out the details to make sure there is a measurable gain for biodiversity around infrastructure and housing”.

Environmental Net Gain

Environmental Net Gain (ENG) follows the same ideas as biodiversity net gain but requires developers to deliver a wider range of environmental benefits over and above the full environmental impact of the proposed development (e.g. air quality, flood risk management). Work is currently underway to explore the implications of such an approach for all stakeholders.