Biodiversity net gain has brought one of the biggest changes to planning we have seen for a long time. The new rule came under the 2021 Environment Act requiring developers to leave the natural environment in a better state than they found it. The legislation makes a 10% biodiversity net gain (BNG) a condition of planning permission for all development sites. It was effective from February this year (2024) on larger developments and extended to include smaller developments from April 2024.
The biodiversity net gain policy is designed to ensure that new developments contribute positively to the environment by enhancing biodiversity. This could involve creating new habitats, planting native species, and enhancing existing green spaces.
In practical terms, it necessitates developers to assess existing and proposed biodiversity values, formulate a plan for enhancement, obtain approval from local authorities and monitor the progress of habitats for years afterwards.
As well as impacting on developers, it will of course impact on planning authorities and land managers.
In this blog, we’ll break down why biodiversity net gain is important, how developers can achieve it, how it works, and any exceptions to be aware of.
Why is biodiversity net gain important?
Biodiversity encompasses the variety of living species on Earth, including plants, animals, bacteria, and fungi (National Geographic). We know that many species are under threat due to human activity – pollution, climate change and population growth. We also know that air quality is poor in many urban areas impacting negatively on the health of people living there.
As habitats shrink, species decline, and air quality worsens, it’s essential to mitigate the negative impacts of construction projects on local ecosystems. Biodiversity net gain is one way of preserving the natural world in the face of urbanisation and development.
By incorporating biodiversity net gain into development plans, developers can help safeguard wildlife, improve air quality, and create healthier and more sustainable communities and ecosystems.
The announcement of BNG in 2021 spurred many local planning authorities to include biodiversity in their plans. It is reported that by March 2023 about 40% of councils already had BNG policies.
How can developers achieve a 10% biodiversity net gain?
Achieving biodiversity net gain requires a proactive and holistic approach to planning and design. Developers have three primary methods for achieving it:
- Creating biodiversity on-site
- Delivering off-site gains
- Purchasing statutory biodiversity credits from the government (although these should only be used as a last resort).
Developers should start by conducting thorough ecological assessments to identify existing biodiversity and potential areas for improvement. From there, they can integrate biodiversity enhancements into their site plans, such as incorporating green roofs or creating wildlife corridors.
Collaboration with ecologists, landscape architects, and other specialists might be required to ensure that biodiversity objectives are met effectively. Additionally, it would also be a good idea for developers to engage with local communities and stakeholders to garner support for biodiversity initiatives and promote awareness of their environmental benefits.
How does the biodiversity net gain (BNG) requirement work?
The new legislation applies to all planning permissions granted in England, with some exceptions. These include permitted development, householder applications, small-scale self-builds, and planning applications made before 12 February 2024. Having said that, planning departments still want to see some improvements in biodiversity albeit on a smaller scale.
Developers should submit a biodiversity gain plan preferably at the same time as the planning application which needs to be approved by the planning authority. The plan must demonstrate a 10% net gain in biodiversity value post-development and address any adverse impact on habitats.
Created, retained and enhanced habitats must be managed appropriately for 30 years to ensure that they attain their target ecological condition. Monitoring is required at various stages to establish progress. If habitats are not developing as they should, then refinements to the management regime are required, alongside further monitoring to gauge success. However, it remains uncertain how the council plans to oversee this maintenance in practical terms.
The biodiversity net gain process typically involves calculating the biodiversity value of a site before development and setting targets for improvement. This can be measured using tools such as DEFRA’s Biodiversity Metric, which quantifies the value of habitats based on their type, condition, and location. Separate BNG calculations are required for habitats, as well as hedgerows and tree lines, and watercourses and ditches, if present on site or within 10 metres in the case of watercourses. A 10% net gain is required for all three of the above, where present in the baseline.
Once development is complete, developers must demonstrate that they have achieved or exceeded the required net gain in biodiversity value. This may involve implementing habitat enhancements, monitoring biodiversity outcomes over time, and providing evidence of successful conservation measures.
Exceptions to biodiversity net gain
While biodiversity net gain is a fundamental principle of sustainable development, there may be circumstances where achieving a net gain is not feasible or appropriate. For example, in cases where development is essential for meeting housing or infrastructure needs, developers may be granted exemptions or allowed to offset biodiversity losses through alternative means, such as funding conservation projects elsewhere.
However, exemptions will only be granted sparingly and only after careful consideration of the potential impacts on local ecosystems and biodiversity. Developers should always strive to minimise harm to the environment and explore opportunities for enhancing biodiversity wherever possible.
Biodiversity net gain is a vital tool for promoting environmental sustainability and biodiversity conservation in the UK. By embracing this principle and integrating biodiversity enhancements into their projects, housebuilders and developers can play a significant role in creating greener, healthier, and more resilient communities for generations to come.
If you’re looking for advice or assistance with making alterations to your workspace or home, contact our specialist team of architects who will be happy to help angus.ellis@waltonhorsfall.co.uk or 01484 602377
