What is a Biodiversity Impact Assessment (BIA)?

The completion of a Biodiversity Impact Assessment is fast becoming the standard mechanism to show a proposal’s potential for biodiversity net gain. In this article RammSanderson explain what is involved in the process and what local planning authorities will expect of a landholder prior to granting planning permission in order to ensure there is a positive net gain.

A Biodiversity Impact Assessment (BIA) is a tool that can be used to quantify the impact that a development is likely to have on the natural environment (negatively or positively), and determine any need for further habitat creation or enhancement, or the need to pay commuted sums in order to ‘offset’ any negative impact.

 Why was it introduced?

The UK’s National Planning Policy Framework (NPPF 2019) was published 24 July 2018 and updated 19 February 2019. This policy mandated local authorities to approve development that would result in economic, social and environmental  ‘net gains’ within the local plan.

In respect of environmental net gains, the NPPF 2019 states that development should ‘contribute to protecting and enhancing our natural environment; including making effective use of land [and] helping to improve biodiversity’.

How is a Biodiversity Impact Assessment determined?

Biodiversity Impact Assessment is concerned with comparing the condition and size of natural habitats before and after the completion of a development.

To do this, it is necessary to survey a site before any site preparation works have begun.

For the first stage of this survey, an extended Phase 1 Habitat Survey should be carried out; this survey method allows the broad habitat types to be recorded and mapped, and also captures information on any protected or priority animal species that may be present at the site.

In conjunction with the Extended Phase 1 Habitat Survey, the condition of habitats will also be graded against the criteria set out in Defra’s Farm Environment Plan (FEP) handbook. Following the initial extended Phase 1 Habitat Survey, a National Vegetation Classification System (NVC) survey will be carried out of particularly sensitive habitats, or those which might be of conservation significance (e.g. semi-improved grasslands), to confirm their classification.

On complex sites, it might be necessary to survey different habitats at different times of year, when the key ‘indicator species’ are possible to identify with certainty. Broadly, the optimal times to survey different habitat types are as follows:

  • Woodlands in spring;
  • Grasslands in mid-summer;
  • Heathlands in autumn, and;
  • Open waters between mid-June and the end of September

Once the survey data has been collected, it is time to input the information into a Biodiversity Impact Assessment Calculator, which is in the form of an Excel spreadsheet.

By inputting the classifications, areas, and conditions of habitats within a development site, the calculator provides the Habitat Biodiversity Value of the site.

At this stage, it is possible calculate the impact that the development will have upon the site’s Habitat Biodiversity Value.

If the site layout and landscape design have not been fixed, RammSanderson will provide advice on the maximising the design of proposals to avoid removing sensitive habitats, with the objective of reducing costs for the developer and the need to offset the removal of these habitats.

If the site layout and landscape design have been fixed at this point, the impact of the proposals will be calculated, and RammSanderson will provide advice on planting schemes and management of landscaping and POS areas, to optimise the potential gains that can be made from these areas.

When the Biodiversity Impact Calculator has been completed, the site’s Habitat Biodiversity Value and the Development Biodiversity Value are compared against one another, with the calculator will generating a Habitat Biodiversity Impact Score, which is a positive or negative number, based on whether the proposals are likely to have a positive or negative impact upon the biodiversity of the site.

In order to meet their responsibilities under the NPPF 2019, a local planning authority will either grant planning permission to a development that has a positive Biodiversity Impact Score, or will condition that commuted sums are paid to offset a negative Biodiversity Impact Score.

Prior to submission of the Biodiversity Impact Assessment Calculator, RammSanderson will consult with a developer to discuss any layout or landscape changes that could be made to avoid or reduce the need to pay commuted sums to the Local Planning Authority.    

What documents must be submitted to the LPA as part of a Biodiversity Impact Assessment?

  • Preliminary Ecological Appraisal (PEA) / Environmental Impact Assessment (EcIA)
  • Extended Phase 1 Habitat Plan data files
  • Landscape Ecological Management Plan (LEMP)
  • Construction Ecological Management Plan (CEMP)
  • Fixed design / landscaping proposals

What if I ignore it?

Under NPPF 2019, a Local Planning Authority mandates that an applicant must demonstrate that a proposal will result in ‘net gain’ for biodiversity, and will not grant planning permission if this cannot be shown. The completion of a Biodiversity Impact Assessment is fast becoming the standard mechanism  to show a proposal’s potential for biodiversity net gain, so if this stage of the process is ignored, it is likely that a local planning authority refuse permission until a Biodiversity Impact Assessment is carried out.

How can RammSanderson Help?

RammSanderson have been working with the Biodiversity Impact Assessment system since 2016, and have demonstratable success in this field, with numerous planning applications granted with our Biodiversity Impact Assessment documenation as part of the submission.

We have the expertise to be involved with a proposal from inception through to submission, with experienced staff able to complete the site surveys, reporting, and digital mapping, as well as being capable complete the Biodiversity Impact Assessment Calculator, advise on optimal landscaping and design layouts, and also hold dialogue with the Local Planning Authority where it would be of benefit for a submission.

Whatever the stage of your planning application, we can provide support for the Biodiverity Impact Assessment, so please contact us if you would like to find out more about how we can help your scheme.