As cities and communities grow, we must ensure that new developments do not continue to harm nature. In fact, with the right approach, development can help improve the environment.
Biodiversity Net Gain (BNG) is a way to ensure that when land is developed, the overall amount of nature and wildlife increases rather than decreases.
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What is Biodiversity Net Gain?
Biodiversity Net Gain means that a development project must leave the natural environment in a better state than before. Instead of just replacing what is lost, developers must improve habitats, plant more trees, and create new spaces for wildlife. The goal is to make sure that nature benefits from new buildings, roads, and infrastructure rather than being destroyed by them.
According to the Chartered Institute of Ecology and Environmental Management (CIEEM), some examples of BNG activities may include:
- Planting native trees or shrubs to provide food and shelter for birds and pollinators.
- Installing green roofs on buildings and shelters using site soils.
- Establishing ponds or wetlands with native plants.
- Creating bird boxes for species like finches, swifts, and swallows.
- Removing invasive species (like Japanese knotweed).
Why Does Biodiversity Net Gain Matter?
Nature is essential for human well-being. Plants, animals, and ecosystems provide clean air, freshwater, and a stable climate. However, urban expansion and construction have led to the loss of many natural habitats. BNG helps to reverse this trend. Here are some key reasons why BNG is important:
Protects wildlife → Helps preserve and restore the homes of birds, insects, and other animals.
Improves air and water quality → More green spaces mean cleaner air and better water filtration.
Helps fight climate change → Healthy ecosystems absorb carbon dioxide and regulate temperatures.
Reduces flooding → Natural landscapes like wetlands and forests help manage water flow.
Creates better spaces for people → Green areas make towns more beautiful and enjoyable to live in.
How Does Biodiversity Net Gain Work?
BNG follows a structured process to measure and improve biodiversity in development projects, typically beginning with an initial consultation and a pre-development field survey, followed by habitat definition, a biodiversity assessment, and a final report with recommendations. Southern Scientific’s ecologists carry out this process from start to finish, ensuring accurate results and compliance with relevant guidance.
For a full breakdown of our step-by-step BNG assessment process, see our Biodiversity Net Gain Assessments page.
Here’s how we perform BNG assessments at Southern Scientific to ensure accurate results and compliance with regulations:
We discuss your project to understand its potential impact on nature and any legal requirements.
Our ecologists visit the site to assess the current biodiversity, collect data, and identify important species and features.
We look at the development plans to understand what the environment will look like after construction and define the new ecological features.
We calculate the biodiversity units for both the current and post-development habitats. These units show whether there is a gain or loss in biodiversity, often as a percentage.
We provide a detailed report on how the development impacts biodiversity. If there is a loss, we suggest ways to improve the site’s ecology, such as creating or restoring habitats.
Regulations in the UK & Ireland
BNG became a legal requirement in England in 2024 under the Environment Act 2021, requiring most developments granted planning permission to deliver a minimum 10% net gain in biodiversity, measured against pre-development figures. The requirement is continuing to expand: the UK Government has confirmed that BNG will become mandatory for Nationally Significant Infrastructure Projects (NSIPs) from 2 November 2026, applying a consistent 10% requirement across all NSIP types with no sector-specific exemptions. Separately, a targeted exemption is under consultation for small residential sites of 0.2 hectares or below.
In Ireland, BNG is not yet a formal legal requirement, and there is currently no nationally recognised method for assessing BNG in the Republic of Ireland. Even so, momentum is building. Several Irish planning authorities now expect developers to demonstrate BNG as part of planning applications, and state bodies such as Uisce Éireann have made “no net loss” of biodiversity and active pursuit of BNG a formal objective in their own biodiversity action planning. CIEEM’s Ireland Policy Group has also published briefing material reviewing how BNG approaches from the UK could be adapted for an Irish context, though it stops short of recommending a specific quantitative metric at this stage.
The developers who follow these practices now will be ahead of the curve if formal regulations arrive in Ireland, which looks increasingly likely. By adopting BNG now, developers can:
- Prepare for future regulations: New environmental laws could soon require BNG in Ireland.
- Improve their reputation: Companies that care about nature are viewed more positively by the public.
- Make planning easier: Many local authorities already look favourably on projects that include biodiversity improvements.
- Support ESG and CSRD reporting: BNG data can feed directly into corporate sustainability disclosures, helping developers and landowners evidence their environmental impact as ESG and CSRD reporting requirements grow.
Working With Southern Scientific
Biodiversity Net Gain is not just about meeting regulations, it’s about establishing methods for sustainable growth. We can build healthier communities and maintain our ecosystems by designing developments that work with nature instead of against it.
At Southern Scientific Services, we are an INAB-accredited environmental consultancy (ISO 17025, registration 194T) with over 30 years of experience delivering scientific and environmental testing across Ireland. Our team of experienced ecologists specialise in Biodiversity Net Gain Assessments for land development projects, guiding you through every stage from initial consultation to final reporting and recommendations.
If you are planning a development project, now is the time to consider how it can contribute to biodiversity.
