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Biodiversity net gain: How can land developers be ready for February 2024?

Part of the UK government’s Environment Act, the biodiversity net gain (BNG) legislation takes effect in February 2024. It requires all land developers to “leave biodiversity in a better state than before” construction started. On each project, from February 2024, developers must create or enhance biodiversity by at least ten percent and maintain those biodiversity gains alongside construction for 30 years. 

This is not just about legislation, though. BNG is about doing the right thing for nature, the environment and the communities that enjoy their local habitats – everyone wins when biodiversity gains.

Biodiversity net gain for land developers: what the legislation says 

You must try to avoid loss of habitat on a piece of land you plan to develop. If you cannot do this, you must create habitat either on-site or off-site. 

On-site means within the red line boundary of the development site. Off-site means either your own land away from the development site, or buying biodiversity units from a landowner who has units that he can sell. 

If you cannot create or buy sufficient biodiversity units then the last resort is to buy statutory credits from the government. You must provide evidence for using this option. The government will invest the money in habitat creation elsewhere in England. 

You may be able to combine all three options to make up your BNG. Before embarking on any course, a developer should obtain legal advice to ensure that all the necessary steps have been followed.  You will need to have your plans for biodiversity gain approved by your local planning authority before you start building. 

Source: https://www.gov.uk/guidance/understanding-biodiversity-net-gain  

Here’s how to prepare for February’s biodiversity net gain legislation 

Understand the requirements 

Biodiversity net gain is a clear government expectation of developers to leave nature in a better state than before. The gain is measured against a pre-development baseline and achieved by creating new habitats, restoring existing habitats and improving habitat connectivity. 

 To be granted planning permission, every land development in England that affects the natural habitat must show it will add value to the environment, either on-site, on land allocated to the development or in biodiversity credits bought for the development. 

 Understand the biodiversity metric 

To calculate biodiversity net gain, the industry will use Defra’s biodiversity metric version 4.0 – and the small sites’ metric, here. These metrics measure the type, condition and size of habitats on a site and calculate its biodiversity value. In doing so, you assess the impact of development on biodiversity.  

To use the metric, your ecologist first needs to identify the habitats on your site, then assess their condition, using Defra’s criteria. Once you have done this you can then calculate the biodiversity score of the site using the metric’s calculation tool.  

A practical problem for developers is that there is a shortage of ecologists to do all these assessments and it is usually only possible to carry out a habitat survey during the spring and summer months. Landmark has therefore built two state-of-the-art screening reports the Landmark BiodiversityCheck and Landmark BiodiversityReport BIODIVERSITY REPORT to give you at-a-glance analysis and a confidence rating for a site, using satellite data, , aerial photography and environmental datasets to help you with your due diligence in the assessment process. 

 The metric also assesses the impact of development on biodiversity. To do this, you need to calculate the biodiversity value of the site before and after development. If the biodiversity value of the site is at least 10 % higher after development than before, you will have achieved biodiversity net gain. If the biodiversity value of the site is lower after development than before, then there is a net loss in biodiversity. 

 Understand habitat value 

The key to minimising the impact of construction on biodiversity is to carry out an ecological survey using the metric.  There will be some rare habitats that cannot simply be replaced or moved, so the aim is to protect them at all costs. An ecologist can help you understand the existing biodiversity value of your development site and identify ways to mitigate damage and achieve that 10 percent net gain.  

Similarly, referencing the Living England habitat probability map, which uses geospatial datasets, satellite imagery and field data records to plot English habitats, can give you a useful starting point.  

Explore best practices 

It is important to remember there is no one-size-fits-all approach to enhancing biodiversity for net gain. The best approach will vary depending on the site and its surroundings. It is important to consult with an ecologist to develop a plan tailored to your specific needs. 

 Whatever the development, implement best practices of: 

  • Being alert to native fauna and flora 
  • Consulting ecologists to ensure the right habitats are in the right places 
  • Communicating with local experts 
  • Linking biodiversity protection to other local protection strategies (health, flood, recreation, and active travel) 

 Ways to promote biodiversity generally 


  • Protect mature trees and nesting sites 
  • Plant native trees, shrubs, hedgerows and wildflowers 
  • Create ponds, wetlands and meadows 
  • Install bat boxes, bird feeders and bee houses to enhance existing habitats 
  • Reduce the use of pesticides and herbicides 
  • Let some areas of the site grow wild 
  • Create green roofs and living walls 
  • Connect habitats with wildlife corridors 
  • Keep light pollution to a minimum to appeal to bats, owls and other nocturnal animals 


  • Support local land trusts and conservation organisations 
  • Donate land to be used for conservation 
  • Purchase biodiversity credits from a habitat bank 
  • Volunteer your time to help with habitat restoration projects 
  • Educate the locals about biodiversity and encourage them to protect and enjoy it 

 Develop a biodiversity gain plan 

With a clearly calculated BNG requirement, you can work with ecologists to develop a plan of specific measures, timescales and budgets to achieve that ten per cent gain. Of course, implementing the plan can be costly, so having a cost-effective tool, like Landmark’s BiodiversityCheck, to work through raw BNG data and gather insights to create a shortlist of sites is useful – as is securing funding early in the development process.  

 If, as the developer, you are funding the habitat creation or restoration, maintenance and monitoring, create a clear, transparent budget. If you’re applying for government or council grants or private investment, ensure you make the applications early, so you don’t hold up development, which might damage the process and the habitat. 

Talk with local authorities and communities 

Work closely with local planning authorities to ensure your BNG plan aligns with their expectations and requirements. By engaging in early discussions with them, you can avoid potential delays in the approval process.  

Similarly, when you communicate your BNG efforts with the local community, conservation groups and stakeholders, you will have more success in getting them to support your vision. By drawing them into discussion, you get the people who will be living with the new habitat to be willing stakeholders. 

At Landmark, to prepare for this exciting change in legislation, we have created legal and geodata-focused products that screen site-specific areas to determine opportunities for biodiversity gains. We recognise the need for quick, cost-effective due diligence in a competitive market, and we are aware of the additional pressures BNG will put on ecologists.  

With licenced information gathered using satellite, aerial photography and environmental datasets, Landmark’s BiodiversityCheck provides at-a-glance analysis and a confidence rating for a site, so land developers can shortlist the right sites first and simply assign the right resources for further review. 

BiodiversityReport uses robust methodology and expert consultant assessment to provide land developers with analysis, data interpretation and a confidence rating without physical inspections or ecologists on site. 



Do you want to get ready for February 2024?

Then watch our Biodiversity Net Gain | How developers can prepare for February 2024 webinar on demand.

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Article originally published by Landmark Information Group.