Biodiversity Net Gain Consultancy: What It Means for Your Site

Biodiversity Net Gain (BNG) is a legal requirement for most development projects in England. It means leaving nature in a better state than before. Since January 2024, developers must deliver at least a 10% net gain in biodiversity to secure planning approval.

This approach goes beyond reducing harm. It ensures measurable improvements to habitats and ecosystems. For developers, BNG is not only about compliance—it is about creating healthier, more attractive spaces for communities and wildlife.

Why Does BNG Matter for Developers?

BNG is part of the Environment Act 2021. Local authorities require developers to prove compliance as part of planning consent. Projects that fail to meet biodiversity targets risk delays and possible rejection.

The benefits extend beyond approval:

• Higher property values in green, nature-rich settings.
• Stronger brand reputation for sustainable practices.
• Better wellbeing for communities.

Natural England data shows that access to green spaces can improve wellbeing by up to 20%, making developments more desirable and resilient.

How is BNG Measured?

BNG uses the Defra Biodiversity Metric. This tool calculates “biodiversity units” based on habitat size, distinctiveness, and condition. Developers must show at least a 10% increase in units compared to the baseline.

If this cannot be achieved within the site, developers may need to consider offsetting or credits.

What About BNG Offsetting and Credits?

Not every development can meet the full 10% on-site. In such cases, developers can:

• Enhance on-site habitats like wetlands, wildflower meadows, or green roofs.
• Offset off-site by funding biodiversity improvements on nearby land.
• Purchase credits from government-approved schemes.

Credits are designed as a last resort and can be expensive. Government estimates suggest costs ranging from £42,000 to £650,000 per hectare, depending on habitat type. This makes early ecological planning the most cost-effective strategy.

Long-Term Monitoring and Maintenance

BNG is not a one-off requirement. Developers must ensure biodiversity improvements are maintained for at least 30 years. This includes:

• Monitoring habitats over time.
• Submitting updates to local authorities.
• Managing landscapes to ensure gains are permanent.

A consultant helps design practical maintenance plans so that sites remain compliant and costs stay manageable.

BNG in Urban Developments

BNG is not limited to rural or greenfield sites. It also applies to urban areas. Developers can achieve net gains by:

• Adding green roofs or walls to buildings.
• Planting street trees and pocket parks.
• Creating sustainable drainage systems (SuDS) with ecological value.

Urban BNG improves air quality, reduces heat, and increases community appeal, aligning with wider net-zero and climate resilience goals.

Community and Stakeholder Benefits

BNG is more than compliance—it builds trust and adds social value. Developments with richer biodiversity create:

• Healthier, more attractive places to live and work.
• Positive engagement with local councils and communities.
• Opportunities for environmental education.

By prioritising biodiversity, developers create lasting legacies that benefit both people and nature.

The Role of a BNG Consultant

A Biodiversity Net Gain consultant ensures compliance while keeping projects viable. At Syntegra, we:

• Carry out baseline ecological surveys.
• Calculate biodiversity units using the Defra metric.
• Prepare Biodiversity Gain Plans for planning applications.
• Explore on-site, off-site, and credit-based strategies.
• Design monitoring and maintenance frameworks.

Working with consultants early reduces risks, prevents costly delays, and ensures smoother planning approvals.

Final Thoughts

Biodiversity Net Gain is shaping the future of development. It is more than a regulatory requirement—it is a chance to add long-term value. By working with a specialist consultancy like Syntegra, you can stay compliant, protect your investment, and create greener, healthier places.

Offsetting, credits, monitoring, and urban strategies all add complexity. But with the right support, BNG becomes an opportunity rather than a challenge.