Maximising Biodiversity Net Gain through built environment frameworks

Biodiversity Net Gain is the enhancement or creation of natural habitats to improve the strength, richness or diversity of the ecosystems that they support by ensuring that development creates a measurably positive impact on the environment.

The activities that enable this to happen are called Ecological Enhancements, which can range from the rewilding of existing spaces right through to the design and creation of brand new habitats and green infrastructure.

The natural world sustains all human life and activity; from providing clean air, water and food, to materials, medicines and energy.

However, the pace at which it is declining is increasing and with the built environment being responsible for nearly 40% of the world’s energy-related carbon emissions, it is vital that we mitigate this.

Improving biodiversity through sustainable construction practices helps to keep ecosystems balanced, maintains the food chain and protect the plants, animals, insects and micro-organisms within them.

Diverse habitats also improve water, food and air quality, provide flood and climate resilience and create health and wellbeing benefits for communities and individuals.

Biodiversity law is being strengthened in countries across the world but not at the speed needed to sufficiently protect and enhance the natural world. Collectively we all have a moral, ethical and social responsibility to align with best practice and champion sustainable construction.

In England, as part of the Environment Act 2021, a minimum of 10% Biodiversity Net Gain is mandatory for all projects that require planning permission, meaning:

• A minimum of 10% net gain to habitats must be met and measured using the biodiversity metric.
  This is the legal requirement; however, local planning authorities may ask for more than this. The bottom line is, the more BNG the better.
• A biodiversity gain plan must be submitted alongside the planning application to the local planning authority.

Habitats must be secured for at least 30 years to fulfil BNG requirements and the maintenance of them is the responsibility of the landowner, supported by planning obligations and conservation covenants.

For developments in London, projects also need to comply with the Urban Greening Factors specified in the London Plan, which requires you to demonstrate an improvement in green coverage by measuring surface area and using specific metrics in line with local plans for each borough.

In Scotland, The Planning (Scotland) Act 2019 and the draft National Planning Framework Policy 3: Nature Crisis (NPF3) include provisions for ‘biodiversity enhancement’. This approach, like net gain, requires the overall improvement of biodiversity, but does not have a specific measure associated with it. The same approach is reflected in Northern Ireland and in Wales regarding the Net Benefits for Biodiversity requirements.

Before applying for planning permission, you need a BNG baseline, which determines the biodiversity value for the site depending on the type of habitat that is being created or improved. Some are more valuable and harder to replace than others, so factors such as size, quality, location and type of biodiversity are considered as part of this.

It is widely agreed that best practice is to deliver Biodiversity Net Gain on-site, as this has the greatest impact. This can be done through landscape planning and green design to incorporate ponds, wildflower beds, native hedgerows, wildlife corridors and green rooves. On-site outcomes should be prioritised, but if they are not possible, BNG can be delivered within the same planning authority through off-site Biodiversity Net Gain.

If there are valid reasons that it can’t be delivered on-site or off-site, or if BNG credits are bought which is also known as Environmental Offsetting, something called the Spatial Risk Multiplier is applied. This is a metric which lowers the value of the BNG activity, making it harder to meet the 10% requirement. This has significant cost, time and resource implications for organisations and acts as a deterrent to discourage the use of these approaches.

Whether you know what outcomes you need or if you want to discuss your options, our team is ready to support you and help you to improve the biodiversity in your community through sustainable procurement.