A groundbreaking approach to planning and biodiversity net gain

The Lichfield Model helps local planning authorities to achieve consistent measurable biodiversity net gain and to increase ecological connectivity, while supporting sustainable development. Justine Lloyd explains how it works.

Covering more than 33,000 ha, Lichfield District in Staffordshire is home to several highly valued Midlands habitats, including lowland heath, woodland and semi-natural ancient woodland, grasslands, rivers, ponds and wetlands.

However, permanent habitat losses to new development and changing land use and more intensive farming threaten Lichfield’s biodiversity, directly and indirectly. The direct effects include permanent destruction of habitats and the populations of species that rely on them, and increased use of pesticides killing priority species.

However, the indirect impacts can be just as damaging, reducing habitat connectivity, through loss of key sites and preventing movements of wildlife. That can isolate populations of priority species that further environmental or artificial perturbations may wipe out.

Lichfield District Council has little direct involvement with or control over local farming activities. However, as the local planning authority, it is determined to conserve habitats and species.

The council’s ecology team created the Lichfield Model in 2015, drawing on experience of more than 6,000 planning applications, planning appeals and public enquiries, ranging from single dwellings to large industrial and national infrastructure projects.

Lichfield wanted to create a simple, robust system that:

  • Could be easily understood by developers and non-ecological experts
  • Would not over-burden officer time
  • Would ensure measurable net-gains
  • Would be constantly achieved
  • Would allow the planning system to support a lasting ecological network across the district without being over-onerous on the developer.

The Lichfield Model includes a policy within the district’s local plan, Policy NR3, and its supporting Supplementary Planning Document, The Biodiversity and Development SPD. The policy clarifies three things:

  • It enshrines the ecological mitigation hierarchy within the Lichfield planning system: “First gather sufficient ecological information; avoidance of ecological harm so far as is possible; mitigation against ecological harm for far as is practical; & appropriate compensation for all residual ecological harm caused”
  • It will approve no development shown to result in a net loss – a legal requirement on all local planning authorities under section 40 of the 2006 NERC Act
  • It requires developments to deliver measurable net gain to biodiversity within the district, under the presumption that it is always possible for a developer to provide a net gain in a system that supports biodiversity offsetting. This position was upheld when the House of Lords considered the NE report on the Ecological Impact of HS2 phase one.

The SPD provides a concise step-by-step approach to dealing with ecology in the planning system, being species-specific and addressing habitat issues. It makes biodiversity offsetting the final step, having explored and exhausted all other options.

It links biodiversity offsets within the district to an adopted biodiversity opportunity map, to create the right habitats in the right place to support a strategic vision of habitat network restoration.

A UK first

The SPD establishes the idea of a biodiversity replacement percentage for the first time in the UK. Lichfield set this at 20 per cent higher than the biodiversity unit value of the habitats lost. A development that will lose habitats equivalent to ten biodiversity units (BU) must compensate by creating habitats valued at least 12BU.

The 20 per cent replacement requirement achieves several things:

  • It requires ecological impacts and gains to be measurable and for developers to use biodiversity metrics to provide a quantitative assessment of impact – how else can they show they have met/exceeded the 20 per cent replacement percentage?
  • By changing ecological assessments in the district from traditional qualitative to quantitative assessments, it reduces ecological jargon, allowing the Lichfield ecology team to talk to developers in language that both parties understand, ie: “Your site has a habitat value of 5BU. Your development will destroy all 5BU, so you need to create 6BU of habitat to get our support on ecological issues”.
  • It steers developers away from the most ecologically valuable habitats within the red lines of their development sites. Valuable habitats – woodlands, heathlands, wetlands – generate substantially more biodiversity units per hectare than low-value habitats such as arable farmland and amenity grassland. The more biodiversity units a development destroys, the more habitat it must provide to compensate, increasing costs for the developer. This makes it more financially sustainable to design developments to retain high-value habitats and to develop low-value sites.

Biodiversity off-setting is a tool to achieve measurable net gain and linked habitat networks off-site. It should not be confused with developments where impact on biodiversity can be avoided or mitigated on-site.

Lichfield requires all biodiversity net gains and compensatory habitat creation – whether within the development site or off-site under a biodiversity-offset scheme – to be secured via planning conditions or by a Section 106 contribution for at least 25 years.

It secures ecological monitoring within the same planning condition, or accounts for the cost of monitoring and all staffing costs within the section 106 contribution. It gives an example of a planning condition, accepted by the Secretary of State as part of a public inquiry, confirming that the biodiversity offset can be managed in perpetuity.


Since it adopted the Lichfield Model, the district council has monitored all major developments to ensure they achieve or exceed the habitat-replacement percentage ratios and are delivering significant biodiversity net gain.

So far, all major applications in the district since 2016 have achieved more than 20 per cent net gain – and several developments have achieved more than 100 per cent. The average net gain score in Lichfield District is 59.3 per cent and the average biodiversity units net gain is 8.04BU.

Net gain and creation of habitats as part of a compensation package has conformed to the Lichfield District biodiversity opportunity map, which aims to safeguard and enhance the ecological network and increase habitat connectivity.

Applicants should integrate new biodiversity benefits within a development scheme, rather than fragment them into isolated pockets or restrict them to peripheral areas. Applicants must also factor in the wider landscape and ecological context of the development to promote and maximise connectivity of habitats, as set out in Policy NR6 of Lichfield District Local Plan.

And the result? Developments are enhancing, restoring and adding to biodiversity, from bird nesting and bat-roosting opportunities, to sustainable urban drainage systems (SuDS) and major new habitat areas. Priority habitat – many hectares of woodland, heathland and species-rich grassland – is being created, restored and managed for 25 years.

Justine Lloyd is ecology manager for Lichfield District Council.

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