Case Study: Achieving Biodiversity Net Gain On Site

The Challenge

Elton Ecology Ltd were approached by our client to provide ecology and biodiversity support for a planning application relating to the erection of a new detached dwelling and garage with associated works and landscaping in the countryside.

The design proposals were developed within the context of ‘Paragraph 80’ (now Paragraph 84) of the National Planning Policy Framework (NPPF). Of particular relevance was circumstance e) of Paragraph 80:

‘e) the design is of exceptional quality, in that it:

– is truly outstanding, reflecting the highest standards in architecture, and would help to raise standards of design more generally in rural areas; and

– would significantly enhance its immediate setting, and be sensitive to the defining characteristics of the local area.’

The Market Bosworth Neighbourhood Plan Policy CE5 also stated that: ‘In the open countryside outside the settlement boundary, new development will only be permitted: […] where it does not cause harm to the landscape or biodiversity of the countryside that cannot be effectively mitigated.’

In addition to policy requirements, the setting of the site was ecologically sensitive, with the site bound by hedgerows with mature oaks present, a woodland copse in the west of the site and a watercourse, Sutton Brook, present at the southeast and southwest site boundaries. A barn was present in the north of the site.

It was therefore essential that the scheme could not only demonstrate that significant negative impacts to biodiversity could be avoided and/or mitigated, but also that the scheme was outstanding in its design and represented significant enhancement for biodiversity and its immediate rural setting.

Following our assessment, BNG standard practice requires that the development would be locked in to delivering the stated habitats to the standard projected for 30 years. Therefore, it was important to work as part of the project team to ensure the habitats were realistic and deliverable in the long term.

Our Approach

Elton Ecology Ltd completed the following work in relation to Biodiversity Net Gain at the site:

• UKhab survey & condition assessment survey
• Baseline and post-development GIS mapping & biodiversity metric calculations
• Attendance at design team meetings, to develop the habitat design proposal
• Liaison with the local planning authority ecology consultee
• Biodiversity Net Gain report

The UKHab Survey & Condition Assessment recorded the baseline existing habitat condition on site in relation to its optimal state; which included other neutral grassland, wet woodland, native hedgerows, and individual trees, from which the BNG calculation would be made. Via condition assessment of the baseline existing habitats on site, Elton Ecology were able to demonstrate the existing site to be of relatively poor to moderate habitat condition, with significant scope to achieve a biodiversity net gain on-site post-development.

The UKHab and Condition Assessment survey data was then mapped via GIS and exported directly into the Biodiversity Metric spreadsheet, allowing for a fast workflow and accurate data migration. The Proposed site plans were also mapped in GIS and exported into the metric, applying professional judgement regarding the habitats to be created in the proposed scheme, in order to maximise the potential to deliver above 10% BNG on site. Post-development habitats included other neutral grassland wildflower meadow enhancement, woodland planting, species-rich native hedgerows, pond creation, and tree planting.

Working as part of the design team, Elton Ecology delivered multiple drafts of the post-development habitat scheme, as the project proposals developed in accordance with other constraints and opportunities on site.

To assess the wider impacts on ecology and biodiversity, Elton Ecology Ltd also delivered:

• Preliminary Ecological Appraisal Report
• Nocturnal Bat Emergence Survey

Outcome

Our Biodiversity Net Gain assessment demonstrated the proposed development could deliver a significant net gain of +64.83% for habitat units and +20.96% for hedgerow units, with trading rules satisfied.

The Preliminary Ecological Appraisal report was able to conclude no significant impacts would arise from the proposed development, subject to the incorporation of mitigation measures.

Working as part of the design team for the site, Elton Ecology were able to design a scheme of habitat creation and enhancement which was compatible with other constraints and opportunities on site, and deliverable on the ground in the long term.

Impact

The Biodiversity Net Gain (BNG) proposals and our Preliminary Ecological Appraisal Report were accepted by the Ecology & Biodiversity consultee on the planning application, subject to the incorporation of mitigation measures outlined in the Preliminary Ecological Appraisal Report.

The scheme design would result in a significant scheme of biodiversity enhancement relative to the existing land use scenario.