Biodiversity Net Gain: 8 Planning Tips for Development

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Biodiversity Net Gain is something to start considering now – it could be essential to achieving planning permission later

Practical Planning Advice
Author Brigid Taylor
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Having finally received Royal Assent, the much anticipated Environment Act 2021 ushers in a new system for the delivery of Biodiversity Net Gain (BNG) and Local Nature Recovery Strategies (LNRS).

What is Biodiversity Net Gain?

In simple terms, BNG is an approach to development which aims to leave the natural environment in a measurably better state than it was beforehand. Planning policy that seeks to protect and enhance biodiversity is nothing new but this latest approach focuses in more on the measurability aspect.

Planning applications will need to quantify the different habitat types on site both before and after the proposed development using the latest Biodiversity Metric. A minimum of 10% gain in biodiversity will be required either on-site or via enhancement elsewhere.

Legal Requirements

Firstly, it’s worth highlighting that BNG is not mandatory everywhere yet but it will become a statutory requirement in 2023 and its importance in the planning process will be elevated. Local planning officers will no longer be free to approve a scheme which fails to achieve 10% BNG despite delivering other benefits (such as housing or community infrastructure) – this may by implication negatively impact the delivery of other aspects of planning gain.

This raises a number of interesting opportunities and potential issues for those engaged in the planning and development world.

Timing Variations

Whilst not yet mandatory, many Local Planning Authorities (LPAs) have started to embed BNG as a policy requirement in their Local Plans, meaning practice will vary from place to place over the next year or two. Bell Cornwell advise on a site by site basis and our in-depth understanding of development plans will provide the necessary local insight for a particular site.

Specialist Skills

The metric requires a certain level of technical knowledge and ecologists will therefore play a key role in carrying out BNG assessments for development proposals. A robust ecology assessment is going to prove advantageous. Our planning consultants can recommend local ecologists and coordinate specialist reports to support planning applications on your behalf.

The recently produced Small Sites Metric could prove useful to those that are not trained ecologists, for example, on developments of 1-9 residential dwellings on sites under 1ha.

Off-setting Schemes

The Environment Act has introduced a new concept, LNRS, to ensure a broader strategy and co-ordinated approach with the aim of delivering networks of well connected habitats. Pilot LNRS are underway but there’s a lot of work to be done. In the meantime, there is the possibility for landowners to deliver offset credits on their own land, which developers of more urban sites could purchase to deliver BNG off-site. The new offsets could also help cash strapped Local Authorities fund green space improvements.

Site Promotion

So, for those involved in site promotion and longer term pipelines of development sites, it is important to consider the current baseline habitats on site. Is a 10% uplift going to be achievable and what impact might this have on the developable footprint of the site? It might be easier to deliver 10% BNG on a site which has low baseline biodiversity value (such as a brownfield site), although this still needs to be balanced against other abnormal costs associated with such projects.

Other Ecological Mitigation

If your proposal also needs to provide other ecological mitigation, Natural England suggest that this will be additional to the BNG requirement – that is, no double counting is allowed. SANG (Suitable Alternative Natural Greenspace) is often provided to offset any potential impact on a protected site (such as the Solent or Thames Basins Heaths SPA). In this example, 10% BNG would need to be achieved in addition to land set aside as SANG, as opposed to the pre-development scenario.

How can we help?

Whilst BNG is not yet a legal requirement, it may already be a local one. Bell Cornwell can advise on your Local Plan conditions and suggest next steps for your development proposal. We advise at all stages of the planning process but for proposals that are still evolving (perhaps just an idea, where pre-application advice has been requested or seeking allocation in a Local Plan) BNG is something to start considering now – it will be essential to achieving planning permission later. Consulting with us early will help prevent holdups further down the line and increase your chances of a successful outcome.

Associate, Brigid Taylor has significant experience in environmental planning aspects of large development proposals and is on hand to help guide you through this developing area of practice.

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