COMMENT | What biodiversity net gain policy means for property

The revised National Planning Policy Framework has strengthened the policy on biodiversity, stating that ‘measurable net gains’ should be secured, writes Georgina Palmer of Tyler Grange.

In simple terms, biodiversity net gain is about leaving the environment in a better state than when you found it.

The Environment Bill is due to be published in 2019/2020 and it is expected that it will then become a legal requirement to deliver BNG on all development sites as part of applications.

Penny Simpson, environmental lawyer and partner at Freeths works with Tyler Grange regularly and said of the forthcoming Environment Bill: “The current lack of any legal requirement for net gain means that the application of the principle has been disparate across the country, resulting in an uneven playing field for developers. The inclusion of a BNG legal requirement in the Environment Act, once it comes into force, will give greater clarity to developers, planning practitioners and decision makers on what is required.”

We are expecting that the Environment Bill will result in the delivery of mandatory BNG, but what further clarity can we expect on how it will work?

The recent DEFRA consultation response provides an insight into how BNG will work, and confirms that:

• 10% will be the minimum required gain
• 30 years will be the minimum period for a compensation site to be managed
• Small sites will be subject to a simplified assessment process
• Nationally significant infrastructure projects and marine developments will remain outside of the scope of mandatory BNG
• The pricing mechanism by which BNG will be assessed, based on a biodiversity metric

So, what are the implications until the Environment Bill is published?

At the moment, Local Planning Authorities are interpreting the NPPF update into their own local policies and many are using different metric systems to measure the delivery of it.

Here in the North West, the Greater Manchester Combined Authority is producing a Supplementary Planning Document which will provide a further locally-specific biodiversity metric for developments within Greater Manchester.

Those of us working on obtaining planning permission for a development need to be reviewing local policy early – preferably before even completing a land deal. This allows us to have a reasonably accurate idea of what the likely cost implications will be for the BNG requirements on that particular piece of land, and avoiding any nasty shocks later in the process.

We would also highly recommend that an agreement over which biodiversity metric to use is made with the relevant LPA at an early stage.

If BNG is a requirement in the NPPF and Local Planning Policy, how do developers deliver it now to achieve a policy-compliant planning application?

There are still some unknowns, such as how BNG will stand in terms of interaction with other site constraints, and what will take priority.

Maintaining scheme viability where significant areas of habitat need to be created could be a huge opportunity for a site and make it marketable to the end user, but it could invariably affect scheme viability.

Whilst off-site compensation will be a possibility, we don’t yet know how this will be implemented and managed. Could it be through a Section 106 agreement, conservation covenant, or will another mechanism be used? How will this be managed and maintained into the future? Most local authorities don’t currently have strategic offsetting sites available, and third-part offsetting brokers have limited sites available so how will the decision be made as to which developments can use off-site compensation and which can’t?

There will also be pressures if you are working in areas where land is too constrained to deliver BNG, potentially affecting the viability of land for delivering much needed housing numbers.

This is particularly notable on Green Belt release sites which have been identified by the LPA to deliver a minimum number of housing units, yet significant Green Infrastructure provision is also required to achieve BNG.

Questions remain around how schemes already consented at outline are to be treated once BNG becomes mandatory. In some cases, it is likely to be difficult to demonstrate BNG at Reserved Matters stage and a way forward for such schemes needs to be determined.

Next steps

Consultants and developers alike eagerly await the publication of the Environment Bill for further clarification on how the government intends to implement BNG.

In the meantime, engaging with an ecological consultant early on can allow developers to provide pragmatic advice on the delivery of BNG for a site, balancing an understanding of the commercial aspects of development against other site constraints.

Ecologists will be able to undertake provisional calculations and assess whether on-site BNG will be possible based on initial designs, and if not, to quantify the potential cost implications of providing off-site compensation to inform your decision-making process. The earlier the better for this, so that you can best plan for the future of your site.

• Georgina Palmer is senior ecologist at Tyler Grange

Contact us for more information – email georgina.palmer@tylergrange.co.uk