Biodiversity Net Gain: The Construction Industry's Environmental Promise

min read time
2021-07-11 08:52:54

What is Biodiversity Net Gain (BNG)?

Like humans, animals and plants need homes; these homes are all around us- our back gardens, local lakes, parks, and forests. The construction industry is tasked with building new homes for us but during this process, the homes of animals and plants are being eradicated, this is where biodiversity net gain comes in. The aim of biodiversity net gain is to ensure that when a new development is completed that there are more potential habitats for animals and plants to thrive than before the development began, hence a gain in biodiversity.

Why is BNG so important?

The world is ever-changing in both positive and negative facets, a negative facet is a continuous decline in biodiversity due to habitat destruction caused by new developments. By 2050, 90% of animals are expected to lose some of their natural habitats due to agricultural processes like deforestation and the disappearance of waterways, the effect of new developments further increases habitat loss. The effects of the changes in the environment and the way animals live are evident with the extinction of species rate 10,000 times higher than the historical level.

Eye-opening statistics like these are exactly why biodiversity net gain is so important to be able to retain habitats for animals and plants to live alongside us in society and prevent extinction levels from increasing any further than this already alarmingly high level.

How is Biodiversity Net Gain currently measured?

On the 7th of July 2021, Natural England launched a new Biodiversity Net Gain metric called Biodiversity 3.0 metric as part of a new sustainable development toolkit. A Small Sites Metric was created alongside the 3.0 to allow for easier calculations of BNG on smaller development sites. Since then, a new updated version, Biodiversity metric 4.0 has been published in April 2022.


Woodland- BNG

What does mandatory Biodiversity net gain mean for developers?

Quite simply, the mandate of BNG means that developers must ensure that they are forward-thinking when it comes to the development of habitats for plants and animals. This means they must prove they’re taking the right initiatives and practices to advance biodiversity rather than aid its continuous decline when applying for planning permission for a new development or construction project.

Some of the potential rules and regulations that need to be complied with by developers include:

  • A minimum of 10% net gain in the biodiversity created was calculated using Biodiversity metrics.
  • Habitats that can be secured for at least 30 years
  • Habitats can be produced on the development site, offsite or via statutory biodiversity credits
  • Registration on a national register for net gain delivery sites

What are the pros and cons of the impending Biodiversity Net Gain mandate?


  • Improved perception of the construction industry in the UK by contributing to the development of an improved environment
  • Fewer habitats are being destroyed, and less deforestation
  • More green spaces for communities to enjoy
  • A minimum 10% increase in biodiversity with every new development
  • New habitats were created aiding animal and plant life
  • New still bodies of water are being created helping with surface water and flood water management
  • More trees being planted lowers the carbon in the air we breathe


  • Longer planning permission processes for new developments with the new BNG regulations
  • Project costs could increase with the added cost of the preservation and advancement of habitats
  • Build times for developments could be increased due to more work to complete impacting developers and the people waiting for the property
  • There may be a lack of knowledge among people within the construction industry over what biodiversity is and how they’re going to take action to improve it.
  • There needs to be awareness spread by the people enforcing biodiversity net gain to ensure that the industry is aware.

Are there any alternatives when biodiversity net gain on the original site is not viable?

The option for offsite compensation is also likely to be included where it is not possible to avoid, minimise or remediate habitat damage on site. In this instance, a developer may opt for offsite compensation or as a last resort purchase biodiversity credits. For certain irreplaceable habitats such as ancient woodland, ancient and veteran trees, blanket bog, limestone pavement, sand dunes, salt marsh and lowland fen, this mitigation approach will not be applied, and they will continue to be protected in accordance with the National Planning Policy Framework (p.68-9, 2019) and the Conservation of Habitats and Species Regulations (2017).

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To help you get ahead of the new changes, this guide covers:

• Why the UK needs a new approach to biodiversity
• The key principles for maximising BNG
• New legal requirements relating to BNG
• How to achieve a 10% net gain through onsite improvements
• How BNG can boost a development’s bottom line

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