Biodiversity Net Gain (BNG)

Biodiversity net gain is a now mandatory element of the English planning system.

The goal of BNG is to leave development sites more biodiverse than they were pre-development by creating and enhancing habitats. It uses a quantitative metric tool to measure losses and gains in “biodiversity units”. Our highly experienced team will guide you through the planning process to ensure your development meets legislative requirements for BNG.

BIODIVERSITY NET GAIN (FOR DEVELOPERS)

Biodiversity net gain (BNG) is an approach to development, and/or land management, that aims to leave the natural environment in a measurably better state for example post-development. BNG became a legal requirement from 12 February 2024 under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021), and mandates a measurable 10% BNG for most new developments in England. BNG is a move away from a more traditional opinion-based assessment to a more quantitative, measurable and transparent based assessment.

There are three ways a developer can achieve BNG.

1. They can create biodiversity on-site (within the red line boundary of a development site).
2. If developers cannot achieve all of their BNG on-site, they can deliver through a mixture of on-site and off-site. Developers can either make off-site biodiversity gains on their own land outside the development site, or buy off-site biodiversity units on the market.
3. If developers cannot achieve on-site or off-site BNG, they must buy statutory biodiversity credits from the government. This should be a last resort. The government will use the revenue to invest in habitat creation in England.

Developers can combine all three options above but must follow the steps in order. This order of steps is called the biodiversity gain hierarchy.

BNG Feasibility Assessment

Our BNG Feasibility Assessment report is aimed at a client or design team to inform them of the feasibility of delivering BNG. In the first instance this assessment includes an ecological walkover survey and habitat (and sometimes river) condition assessment to ascertain the habitat type, condition and distribution within the site. It should be noted that much of this information is captured as part of the ‘preliminary ecological appraisal’ (PEA) which should normally precede BNG Feasibility Assessment. The statutory biodiversity metric or small sites metric tool is then used to calculate the biodiversity baseline value of a site pre-development and the predicted biodiversity value of a site post-development using detailed design information. As a minimum, a BNG Feasibility Assessment (including the statutory biodiversity metric) must be submitted to the planning authority for a planning application to be validated.

The Biodiversity Net Gain Feasibility Assessment report aims to:

• Assess at the project feasibility stage as to whether the project can deliver BNG, or not, for all of the development options being considered;
• Advise how the project can maximise its ability to deliver BNG considering factors such as location, design, construction methods and programme (where relevant);
• Consider the potential for on-site or off-site delivery of BNG or purchase of statutory biodiversity credits in-line with the biodiversity gain hierarchy.

Biodiversity Gain Plan

A Biodiversity Gain Plan must be submitted to and approved by the planning authority to discharge the biodiversity gain condition prior to the commencement of development. The Biodiversity Gain Plan sets out how the measurable 10% BNG will be met for the development granted planning permission.

Habitat Management and Monitoring Plan (HMMP)

A HMMP should be submitted alongside the biodiversity gain plan (to discharge the biodiversity gain condition). If you’re delivering off-site gains, the HMMP should be agreed with either the local planning authority and secured through a planning obligation (section 106 agreement), or with a ‘responsible body’ if you’re securing gains with a conservation covenant. If you’re delivering ‘significant on-site enhancements’, the HMMP should detail how proposed habitats will be initially created and enhanced and how they will be managed and monitored over a minimum 30-year period.

BIODIVERSITY NET GAIN (FOR LAND MANAGERS)

The above is a planning / development-led approach to BNG. However, with the steady rise in natural capital markets becoming available in the UK, land managers (i.e. farmers and estate owners) can also sell off-site biodiversity units (as well as other natural capital products including carbon and nutrient credits), either directly or through a habitat bank operator, to developers to fund nature recovery work / rewilding initiatives and ecosystem services on their land, which could be a significant source of additional revenue.

PJC Consultancy can work with land managers on nature recovery work / rewilding initiatives to initially calculate the biodiversity baseline value of a site pre-intervention and then advise on site-specific habitat enhancement initiatives that reflect local nature recovery strategies and that can maximise the biodiversity value of a site post-intervention, thereby maximising the biodiversity uplift and profitability of nature recovery work / rewilding initiatives.”