Understanding biodiversity net gain

Biodiversity Net Gain (BNG), introduced by the Environment Act 2021, became mandatory in England from 12 February 2024. BNG has been established to ensure that any development has a positive impact on biodiversity. The goal of BNG is to create new habitats while also enhancing existing ones, thereby ensuring the retention and improvement of the ecological connectivity they offer for wildlife.

Development frequently leads to impacts on and the loss of natural habitats. BNG demands that development contributes more to nature. It establishes a requirement for a minimum 10% increase in biodiversity compared to what was present before development started. Consequently, BNG will result in the creation of more and higher-quality habitats for wildlife to flourish in, while also providing enhanced opportunities for people to enjoy nature.

Calculating biodiversity

Should your development be subject to BNG, it must employ the metric tool. A Biodiversity Metric is employed to measure BNG, typically by a qualified ecologist. However, if your development is small in scale, hiring an ecologist is not mandatory. Instead, you have the option to utilize the simplified Small Sites Biodiversity Metric tool independently, or someone familiar with the site can conduct a survey and perform the calculation. This individual could include the project manager, a gardener, or a landscape architect.

Biounit trader can help you in the process of identifying and engaging with the right agent to calculate your Biodiversity Metric. The metric is complex and assesses changes in both the quantity and quality of habitats as an indicator of natural conditions, comparing the habitat present on a site before and after development. This comparison relies on four fundamental factors: habitat size, condition, distinctiveness, and location.

In simple terms, a developer is provided with the number and type of Biodiversity Units needed to achieve 10% net gain. The developer then decides how these are to be achieved.

Achieving biodiversity net gain

There are three ways in which BNG can successfully achieved during the planning process, each can be used independently or in any combination.

On-Site Units

A developer can make full or partial 10% BNG through habitat creation or enhancement using landscaping and green infrastructure within the red line boundary of a development site.

Off-Site Units

If there is insufficient BNG net gains through on-site habitat creation, a developer can seek to purchase off-site units to achieve the remaining 10% BNG. This is facilitated by habitat creation or enhancement strategies in collaboration with both public and private land managers such as a landowner, farmer, estate owner, habitat bank operator, land agent and land advisor. Biounit trader matches developers with land managers, supplementing on-site BNG with off-site habitat creation. The unit price of off-site units are dictated by the land manager and advertised on biounit trader. The cost per unit is affected by market forces plus habitat distinctiveness, broad habitat type and specific habitat type.

Credits

Should a developer fail to achieve on-site or off-site BNG, they are required to purchase statutory biodiversity credits from the government, which should only be considered as a final option. The government will utilize the generated revenue to fund habitat creation projects in England. Statutory biodiversity credit prices are published by the government and are reviewed every 6 months. They are calculated based on habitat distinctiveness, broad habitat type and specific habitat type. The price per credit is kept excessively high, ranging from £42,000 to £650,000 to encourage the use of on-site and off-site biodiversity units. The current government biodiversity credit price list was last updated by 12 February 2024 and is shown here.