BNG and Planning – What Developers Need to Know

The 2 April 2024 saw mandatory Biodiversity Net Gain (BNG) regulations come into force for “minor’’ planning applications. This follows the introduction of mandatory BNG for major applications from 12 February 2024. The statutory BNG requirement is for development to deliver at least a 10% increase in biodiversity value relative to the site’s pre-development biodiversity value, which must be secured for at least 30 years.

The concept of making sure new development leads to an enhancement in biodiversity has been around for many years and was included in the first version of the National Planning Policy Framework (NPPF) published in 2012. However, it is only this year, that mandatory BNG, which was introduced by the Environment Act 2021, becomes a statutory requirement in planning applications.

There are new minimum requirements required to be submitted with each applicable application including information in respect of the application site’s pre-development biodiversity value and a completed biodiversity metric and a plan showing the on-site habitat.

Each applicable permission will be subject to a BNG planning condition requiring a biodiversity gain plan to be submitted which cannot be amended via an amendment application as is possible with other planning conditions (eg via a s.96a or s.73a application).

The biodiversity value can be delivered on site, off site via an agreement with a third party or through a broker or through a new biodiversity credits scheme which can be purchased from the Secretary of State, with Natural England acting as the broker. These credits will be deliberately uncompetitively priced to encourage developers to deliver on site or off site wherever possible. The BNG metric also incentivises provision of biodiversity solutions close to the subject site through use of a spatial multiplier which effectively reduced the biodiversity value of habitats delivered further from the subject development site.

There are exceptions from BNG requirements, which include but are not limited to:

• Reserved Matters applications

• “De Minimis” development - development which does not impact a priority habitat and also impacts less that 25 square metres (5m by 5m) of on-site habitat or 5 metres of on-site linear habitats such as hedgerows

• Development granted Planning Permission by a development order eg “Permitted Development”, permitted by the GPDO, 2015 (as amended)

• Householder development

• Urgent Crown development.

The current BNG metric also identifies that temporary impacts on habitats that can be restored within two years can be excluded from the BNG calculations.

S.73 applications to amend planning permissions may also trigger the need for a new BNG plan. However, where the parent permission to be amended was granted prior to 12 February ("major" development) or 2 April (“minor” development), no BNG requirements apply.

The BNG planning condition ensures that the required solution is a “post-permission matter” and dealt with via condition. However, the route to secure the 10% uplift even with minor applications will need to be considered up front and as the scheme design is developed ensure the condition can be discharged. In most instances it will be most cost effective to deliver some or all of the habitat value on land owned or controlled by the developer.

The impacts are likely to be keenly felt by already-stretched Local Planning Authorities (LPAs) who will need new ecological resource to assess BNG information within planning applications. Where off-site gains or biodiversity credits are required, s.106 legal agreements will often be required which will be place additional burdens on Local Authority legal teams.

The alternative to s.106 agreements is the currently largely untested route of securing the uplift via a “Conservation Covenant’’, a private, voluntary agreement between a landowner and a “responsible body", such as a conservation charity, government body or a local authority. It will be interesting to see how widely these are taken up, but many developers may prefer the devil they know and stick with s.106 agreements initially.

As many developers will have experienced, the UK faces a shortage of suitably qualified ecologists, both in the public and private sectors, before the introduction of BNG nationally. The additional work required from the introduction of BNG has further exacerbated this shortage in expertise and is expected to lead to delays in preparing and determining planning applications.

One area which might improve efficiencies for both developers and LPAs in assessing and providing for BNG is Artificial Intelligence (AI). In order to improve options for clients, our Planning team are trialling partially-automated AI assessments of sites using high quality commercial-grade aerial photography. While the legislation requires a suitably qualified person to visit a site, this may offer significant opportunities for ecologists to cut timescales and costs and review BNG enhancement options.

To discuss any of the matters discussed above or any other planning matter, please contact the team.