Preliminary Ecological Appraisal and BNG assessment for Eyhorne Street, Hollingbourne

The client

Cantium Land and Development Ltd, who commissioned Adonis Blue Environmental Consultants to deliver a Preliminary Ecological Appraisal (PEA) and Biodiversity Net Gain (BNG) assessment for a proposed development at Eyhorne Street, Hollingbourne.

The challenge

Ahead of submitting a planning application, the client needed to identify any ecological constraints on the site, understand the potential impacts of development on habitats and protected species, and ensure the scheme aligned with biodiversity enhancement principles under current planning policy.

What we did

A qualified ecologist carried out a site visit to deliver the PEA, including habitat identification and mapping, assessment of ecological constraints, and evaluation of potential impacts on protected and notable species. In parallel, we conducted a BNG assessment, involving baseline habitat classification and condition assessment, calculation of biodiversity units, and support in designing post-development habitat proposals to achieve measurable net gain. The PEA found that ecological constraints — relating to nesting birds, hedgehogs, badgers, hazel dormice, foraging and commuting bats, reptiles, and great crested newts — were manageable with appropriate mitigation, and that no further detailed surveys were required. We incorporated a range of mitigation and enhancement measures into the development design, including timing vegetation clearance to avoid bird nesting season, retaining habitat and applying sensitive site management, installing wildlife-friendly features such as hedgehog access points and bat boxes, and creating and enhancing habitat to support protected species.

The outcome achieved

The BNG assessment demonstrated a 21.37% increase in habitat units and a 667.24% increase in hedgerow units, delivering an overall 21.37% net gain in biodiversity — comfortably exceeding standard policy requirements. The scheme achieved a measurable, policy-compliant biodiversity net gain, incorporated practical and effective mitigation measures, and enhanced the site's ecological value beyond its original baseline. As a result, the development received a resolution to grant planning permission, with biodiversity set to improve significantly as part of the scheme. The project demonstrates how early ecological assessment and thoughtful design can deliver positive outcomes for both development and the natural environment.