Biodiversity Net Gain and the Changing Role of the Managing Agent

BNG Changes the Nature of Estate Management Risk

Under the Environment Act 2021, most new developments in England must deliver at least a 10% biodiversity net gain, secured for a minimum of 30 years through planning conditions, Section 106 agreements or conservation covenants.

Responsibility for maintaining this gain typically passes to the Resident Management Company (RMC) or a community trust, and to managing agents acting on their behalf. This represents a clear shift in both risk and knowledge burden.

Biodiversity outcomes are legally binding. Where habitat creation fails, planting is poorly implemented, management regimes are inadequate, or monitoring obligations are missed, the responsible entity may face enforcement action, remedial costs and reputational damage.

Managing agents therefore sit at the sharp end of an obligation that begins before residents move in and continues long after the developer has exited the site.

Green Infrastructure Must Be Treated Like Built Assets

Managing agents have long applied rigorous standards to the handover of buildings and constructed assets. Historically, landscape and green infrastructure have not received the same level of scrutiny.

Under BNG, habitats created to secure biodiversity gain form part of a legally enforceable ecological strategy. They require correct installation, appropriate maintenance and long-term monitoring.

A competent managing agent should expect, as a minimum, a comprehensive green space handover pack including:

• Approved biodiversity metric calculations and baseline surveys 

• The Habitat Management and Monitoring Plan (HMPP/HMMP) 

• Detailed landscape specifications and planting schedules 

• Evidence of compliance with Section 106 obligations 

• Defined monitoring and reporting requirements over the 30-year period 

Without this information, managing agents inherit liabilities they cannot effectively control or defend.

The Critical Importance of Build-Stage Due Diligence

A key implication of BNG is the need for managing agents to engage earlier in the development lifecycle, creating a continuous “green thread” from planning through construction to long-term management.

The success of BNG depends heavily on build-stage decisions: soil preparation, planting quality, sequencing of works, habitat protection and delivery of sustainable drainage systems (SuDS). Errors at this stage can undermine biodiversity outcomes and lead to costly remediation.

Managing agents must be prepared to challenge developers and stakeholders. This requires confidence and a willingness to ask critical questions, such as:

• Has the landscape been installed in accordance with planning approvals and Section 106 requirements? 

• Are the correct habitat types delivered in the right locations and at the correct scale? 

• Has the HMPP been properly implemented, or merely referenced? 

• Are SuDS features designed with long-term access and maintainability in mind? 

Without this scrutiny, long-term obligations may be compromised before management begins.

A New Skill Set for a New Management Model

BNG does not require managing agents to become ecologists, but it does demand a broader and more technical skill set. Agents must be capable of interpreting ecological documentation, commissioning specialist advice and understanding what success looks like on the ground.

Key areas of competence include:

• Understanding biodiversity metrics and performance measures 

• Managing ecological surveys and monitoring programmes 

• Procuring and overseeing specialist landscape and habitat contractors 

• Translating ecological objectives into practical management plans 

• Budgeting for long-term maintenance and remediation 

These skills must be embedded across organisations rather than treated as niche expertise. BNG is now a mainstream feature of development, and failure to adapt exposes both managing agents and their clients to long-term risk.

From Passive Management to Responsible Stewardship

Estate management has traditionally been reactive, maintaining assets and responding to issues within cost constraints. BNG fundamentally challenges this approach.

Maintaining biodiversity gain over 30 years requires active stewardship. Habitats must establish, mature and adapt. Monitoring outcomes may require changes to management regimes, and regulatory bodies will increasingly expect transparency and accountability.

This shift requires managing agents to:

• Refuse handovers where delivery or documentation is incomplete 

• Escalate risks to biodiversity assets early 

• Defend long-term management budgets aligned with legal obligations 

• Provide clear advice to RMCs and community trusts on risk and liability 

This is a move from passive oversight to accountable stewardship.

Community Engagement: The Final Piece of the Puzzle

BNG is not only about ecological outcomes; it is also about improving the quality of places where people live. Community engagement is therefore critical.

Residents who understand why meadows are left to grow, why certain areas are protected, or why drainage features appear natural are more likely to support them. Poorly explained landscapes can lead to complaints and pressure to alter features in ways that undermine biodiversity objectives.

Managing agents play a key role in bridging this gap. Through clear communication and engagement, agents can foster shared responsibility and support long-term stewardship.

Conclusion: A Defining Moment for Managing Agents

BNG represents a defining moment for the property management profession. It elevates the importance of green infrastructure, extends long-term accountability and demands a higher standard of practice.

Managing agents who strengthen their skill sets, insist on rigorous handover processes and embrace a stewardship mindset will protect their clients and position themselves as leaders in a changing sector.

The future of successful developments lies not in short-term maintenance, but in long-term care. In the era of Biodiversity Net Gain, managing agents play a critical role in ensuring that both communities and the landscapes that support them are built to last.

Helen Roberts, Director of Client Services, Fexco Property Services