Biodiversity net gain is an approach to development that aims to “leave the natural environment in a better state than before”.

This approach encourages developers to increase natural habitats for the wildlife and for biodiversity to thrive, consequently preventing the loss of biodiversity throughout the UK and to halt any further decline. The biodiversity net gain is part of the 25-year proposed plan for improving the Environment, there is an ongoing emphasis on delivering biodiversity enhancement as part of development.

The natural environment has often been significantly impacted by development. However, the Environment Bill which received Royal Assent on 9 November 2021 requires any new development that results in loss of habitat to provide a mandatory biodiversity net gain of 10% to be maintained for a period of at least 30 years which will be secured via obligations or conservation covenants. This will result in developments being unable to commence until a biodiversity gain plan has been approved.

The National Planning Policy Framework already states that the planning system in England should provide biodiversity net gains where possible. However, the introduction of biodiversity net gain in the Environment Bill imposes mandatory and measurable improvements for biodiversity by creating or improving habitats associated with development.

The change in legislation means that local planning authorities will only approve the biodiversity gain plan if the biodiversity value attributable to the new development exceeds the pre-development biodiversity value by at least 10%. The government’s biodiversity metric will be used to determine whether the proposed net gain will be achieved.

The metric works by identifying the site boundaries, dividing the site into parcels according to the different types of habitats then considering factors such as the type, condition, significance, and size of each habitat. The metric then creates a numerical value of the site by converting the information into a numerical score. Upon development, it must be ensured that the original numerical score is increased by at least 10%.

Examples of how to achieve biodiversity net gain includes taking measures to recreate or enhance habitats following development, for example including a nature reserve within the development and restoring natural habitats. The gain can also be provided offsite, if onsite is not a viable option and there are no proximity requirements. The offsite area must be recorded on a biodiversity gain site register and provide for a 30-year commitment to maintain the gain. Alternatively, there will be an option for developers to purchase credits from The Secretary of State, the money received will then be used for the purpose of habitat enhancement.

The requirement of mandatory biodiversity net gain will apply to all new developments. However, minor developments which include residential developments of 1-9 dwellings on a site under one hectare and non-residential development where the floor space is less than 1,000 square metres or where the site area is less than one hectare will be subject to a simplified assessment.

With the Environment Bill now having gained Royal Assent, the implementation of biodiversity net gain will be driven by new legally binding environmental legislation.

For further information, please contact our property team on or 01753 889995.

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