The ‘Net Gain’ Consultation

January 31, 2019

By Peter Dixon

The ‘net gain approach’ is an important theme in the 25 Year Environment Plan which states that the approach will become embedded in the planning system in England.  The theme is echoed in the Agriculture Bill that is currently before Parliament which contains provisions enabling the Secretary of State to introduce a replacement for the current system of farm support when the UK is no longer subject to the Common Agricultural Policy: the first purpose for which it is proposed to give the Secretary of State the power to provide financial assistance is managing land and water in a way that “protects or improves” the environment. There are indications that when the new the payments regime is introduced there will be a shift in emphasis to the provision of ‘public goods’ such as landscape or nature conservation.

The revised NPPF states that planning policies and decisions should contribute to and enhance the natural and local environment. Against that background it is advised that plans should identify and pursue opportunities for measurable net gains for biodiversity and that in determining planning applications local planning authorities should refuse permission where there would be significant harm to biodiversity and the harm cannot be avoided  – whether by locating the development on an alternative site, providing adequate mitigation or “as a last resort” compensated for.

It is hoped that by allowing a developer to compensate for the loss of biodiversity by creating and managing replacement (off-site) habitat it will be possible to reconcile the competing needs for development and for nature conservation.  The current consultation paper states as follows:

“An effective net gain policy could enable us to build the houses, commercial premises and local infrastructure we need and at the same time improve the environment by more than compensating for biodiversity loss where it cannot be avoided or mitigated.”

A particular challenge is to place a value upon existing biodiversity and upon any replacement proposed in compensation on a consistent and objective basis.  In 2012 DEFRA and Natural England consulted on a biodiversity metric which was intended to address the problem by providing a tool to enable the before and after comparison to be carried out in a transparent and verifiable way using a scoring system based on ‘biodiversity units’.  Put simply, to achieve a net gain, a development must have a higher biodiversity unit score after development than before.  The metric has been road tested in a variety of settings since then and an updated version (‘DEFRA Metric 2.0’) is said to be in preparation.

Another challenge is how to ensure that any compensating measures are delivered and thereafter secured with any necessary management for the long-term.  Existing mechanisms as such as planning obligations and the Community Infrastructure Levy have limitations in these respects. In 2013 the Law Commission published proposals for a new form of long-term ‘conservation covenant’ intended to run with land and be enforceable by designated responsible bodies (e.g. local authorities, nature conservation or heritage agencies, etc).   The consultation paper indicates that the Government now plans to legislate to implement the Law Commission’s proposals.