Biodiversity Net Gain

What is Biodiversity Net Gain?

Biodiversity Net Gain (BNG) is about “leaving biodiversity in a better state than before”. As part of the Environment Act it is now mandatory for all development schemes in England to deliver a 10% BNG and maintained for at least 30 years. To achieve BNG, a project must incorporate a measurable increase in natural habitat over and above what is lost. It can be achieved on-site, off-site, or through a combination of measures.

By considering BNG as early as possible in the design process you can reduce the risk of completing a scheme with a net loss. Creating a development with a net loss is not only a risk on the local biodiversity, but it could result in substantial offset costs.

What is a Biodiversity Net Gain Assessment?

A BNG Assessment compares baseline conditions to post-development plans. BNG is achieved if the post-development plans provide a net improvement to the biodiversity of a site.

As biodiversity uses habitats as a proxy for measuring biodiversity and ecological value a number of Good Practice Principles must be applied within the assessment to ensure a holistic and well-rounded development which truly improves the ecological value of the site. The mitigation hierarchy ensures that all onsite opportunities for improving biodiversity have been maximised before offsite mitigation is considered.

Avoidance - Avert from negative impacts on the habitat if possible. Examples include finding an alternative site, retaining habitat features, or changing work timings. This is the most preferred option.

Minimise/Mitigate - Measures that aim to reduce impacts to the point where they have no adverse effects.

Compensate - Measures that compensate for residual losses of biodiversity.

Offset - Where losses of biodiversity can’t be compensated for on site. This should be a last resort.

Although we recommend that BNG is considered as early as possible in the development process, the assessment can be undertaken at several stages which dictates the specific assessment required;

• Identifying implications for potential development projects at any scale from single unit to whole estate and portfolio
• Audits of land for biodiversity gain capacity at land acquisition stage, akin to risk assessment or due diligence.
• Providing advice on options for delivery of biodiversity gain on and off-site.
• Modular River Survey Assessment.

Assessment and Design Stage
• Baseline survey and habitat condition assessment
• Design-phase Biodiversity Enhancement Strategy: advising on the retention of ecological features, scope for habitat creation and enhancement.
• Combining green infrastructure, Local Nature Recovery Strategies, SANG and habitat provision.
• GIS expertise: managing metric data and supporting calculations.

Planning Consent and Delivery
• Planning conditions/obligations: working with a project team to ensure that the proposed requirements are reasonable, proportionate and practical.
• Preparing long-term (30 years) Habitat Management Plans and advising on future management commitments.
• Site-based advice and expertise in working with contractors to deliver habitat creation, restoration and enhancement.
• Liaison and negotiation with local authorities, conservation organisations, and other third parties for agreeing the delivery of biodiversity gain.
• Identification and negotiation of land and schemes for offsite compensation.

Our Expertise

At Urban Green, we have a diverse team of BNG experts that will support your development along the entire process from feasibility to completion, which would include;

Our CIEEM accredited ecologists will undertake a baseline field survey, a habitat condition assessment and desk study in order to calculate the baseline biodiversity unit score for the site. (These can be completed alongside a preliminary ecological appraisal for the proposed development).

Our geographic information system (GIS) team will create accurate habitat measurements based on our initial surveys. We will then feed this into the metric to produce a biodiversity baseline unit for the site.

We will inform you of any potential net losses as early as possible in the design process. We can also provide recommendations on what habitats could work, where they should be located and how to layout the site in a way to maximise net gain.

Our team of Landscape Architects and Urban Designers will work with you and the ecologists to design a scheme for BNG. Whether the initial calculations show a gain or a loss, the landscape team will aim to maximise the biodiversity output for the development.

On completion of the design process and finalisation of the calculations, we will produce a concise and robust assessment report of the biodiversity output for your development.

Free Biodiversity Net Gain CPD sessions for your business

BNG is a complex matter and, at first glance, can seem daunting. To help you and your team understand BNG and how to deliver it, we can provide an informative CPD webinar covering everything you and your team need to know about BNG and its mechanisms for delivery. To find out more about our online webinar, get in touch.

Biodiversity Net Gain services

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