ISO 17620:2025

Overview

ISO 17620:2025 - "Biodiversity - Process for designing and implementing biodiversity net gain in development projects" provides a structured, auditable process to plan, deliver and verify biodiversity net gain (BNG) outcomes across the life cycle of spatially explicit development projects. The standard covers terrestrial, freshwater and intertidal habitats (down to mean low water), aligns with the Convention on Biological Diversity and the Global Biodiversity Framework, and is applicable across sectors (residential, energy, transport, agriculture, forestry, extractive industries, infrastructure, etc.). It supports projects that have high, limited or no biodiversity impact and those achieving BNG onsite, offsite or both. Note: ISO 17620 does not detail the specific technical delivery requirements for biodiversity enhancements or management actions, nor the different approaches required for marine habitats.

Key topics and requirements

• BNG process stages: preparation; environmental assessment and design; implementation; management, monitoring and reporting - mapped to Plan‑Do‑Check‑Act.
• Baseline and measurement: establishing a biodiversity baseline and using indicators to measure biodiversity change.
• Mitigation hierarchy: identification of impacts, avoidance, minimization, restoration and offsets where required.
• Measurable BNG targets: setting, documenting and prioritizing quantifiable targets (including like‑for‑like or better and additionality considerations).
• Feasibility and option appraisal: assessing the feasibility of achieving BNG and informing project design decisions.
• Time and distance considerations: reducing time lags and spatial distance between losses and gains.
• Governance and documentation: requirements for BNG commitments, management and monitoring plans (MMP), BNG agreements, record management and reporting.
• Auditing and verification: provisions for auditing project BNG processes and outcomes.
• Risk and exclusion: guidance to avoid projects that negatively impact protected or irreplaceable biodiversity features.
• Supporting annexes: informative guidance on process elements, irreplaceable features, example design measures and BBOP principles on biodiversity offsets.

Applications and users

ISO 17620 is practical for organizations that need a consistent, transparent framework to design and demonstrate biodiversity net gain:

• Developers, project managers and planners
• Ecologists, environmental consultants and conservation practitioners
• Infrastructure, energy, agriculture and forestry companies
• Land managers and restoration project teams
• Planning authorities, regulators, auditors and investors

Benefits include improved regulatory and stakeholder confidence, clearer decision‑making for project options, documented measurable outcomes, and alignment with international biodiversity targets.

Related standards and guidance

• ISO 14001 (environmental management; Plan‑Do‑Check‑Act alignment)
• BBOP Principles on Biodiversity Offsets (referenced in Annex D)
• Convention on Biological Diversity and the Global Biodiversity Framework

Keywords: ISO 17620, biodiversity net gain, BNG, biodiversity baseline, mitigation hierarchy, monitoring, management plan, ecological design.