The Senedd's approval of the Environment (Principles, Governance and Biodiversity Targets) (Wales) Bill (the Bill) on 24 February, and its consequent Royal Assent in April to become the Environment (Principles, Governance and Biodiversity Targets) (Wales) Act 2026 (the Act), marks an evolution of how environmental matters must be considered across Wales's regulatory landscape.
The Act has clear implications for environmental governance and biodiversity, and Welsh ministers have provided an explanatory memorandum that provides a guide to the provisions in the Act.
This article explores what the new framework means for planning practice and project delivery.
New statutory baseline for environmental decisions
The Act is set out in four parts.
- Part 1 focuses on environmental objectives and principles.
- Part 2 establishes the Office of Environmental Governance Wales (OEGW).
- Part 3 introduces legally binding biodiversity targets.
- Part 4 sets out the regulation powers and when each provision will come into force.
The Act enshrines four environmental principles into Welsh law:
- precaution
- prevention
- rectification at source and
- polluter pays.
These principles will be applied by ministers and Natural Resources Wales when preparing environmental policy, and certain other public authorities when carrying out strategic environmental assessment.
For the planning system, this creates an expectation that environmental impacts are considered early, systematically and proactively. Local planning authorities (LPAs) preparing development plans, and Welsh ministers determining major development or infrastructure projects, will likely need to demonstrate how:
- harm has been prevented rather than mitigated
- the ability to rectify impacts at source has been assessed and
- the costs of environmental damage have been internalised in scheme design.
While this reinforces the importance of robust evidence in planning decisions, it largely aligns with existing requirements established under Planning policy Wales (PPW) in Chapter 6, 6.1 Historic Environment, and will continue to shape environmental impact assessment and related environmental processes in Welsh planning.
Office of Environmental Governance Wales created
A central feature of the Bill is the creation of an independent watchdog, the OEGW, which will be empowered to hold public authorities to account for compliance with environmental law.
For planners and promoters of major schemes, this means:
- a clearer route for third-party complaints about compliance with environmental duties
- greater emphasis on robust, transparent reasoning in planning reports and decision notices and
- the potential for OEGW investigations to intersect with or run parallel to planning processes.
This will add a new governance layer to the Welsh planning system, emphasising the need for decision‑makers to evidence their consideration of environmental obligations.
Legally binding biodiversity targets set
By requiring Welsh Ministers to set legally binding biodiversity recovery targets, and by amending the Environment (Wales) Act 2016 to establish a structured target-setting framework, the Act creates a statutory driver for nature recovery in which planning will play a central role.
The Act places a duty on Welsh ministers to set at least one target in priority areas such as native species, effective management of ecosystems, pollution reduction and quality of evidence.
Once targets are adopted, LPAs and developers should expect:
- stronger biodiversity enhancement requirements in local development plans
- greater scrutiny of scheme‑level biodiversity net gain (BNG) outcomes and
- more consistent integration of resilience and ecosystem services into planning assessments.
Although Wales has not mirrored England's mandatory 10% BNG regime, the new targets will nonetheless exert material weight in planning decisions.
In practice, this is likely to narrow the gap between policy-led enhancement and mandatory expectations at the application stage.
There is also a duty on Welsh ministers to promote awareness of the importance of, and threats to, biodiversity.
'The Act creates a statutory driver for nature recovery in which planning will play a central role'
What does this mean for strategic planning, infrastructure and thresholds of acceptable harm?
The Act's strengthened governance and biodiversity framework will directly influence the following.
- National planning policy updates: future revisions of Future Wales: The National Plan, Planning Policy Wales and technical advice notes.
- Design and consenting strategies: for major energy, transport and water infrastructure, particularly where projects interact with sensitive habitats.
This is particularly relevant for promoters where front‑loaded environmental reasoning for design decisions taken will become increasingly important in justifying impacts on the environment.
The Act reinforces Wales's environmental governance, with direct consequences for the planning system. By mandating stronger environmental principles, establishing an independent oversight body and putting biodiversity recovery on a statutory footing, Wales is signalling that planning must fully embed environmental protection at every stage.
While the direction of travel suggests planning decisions in Wales will continue to emphasise integrated and transparent consideration of environmental outcomes, it is worth noting that the existing consenting processes already provide a robust framework for environmental assessment and scrutiny.
A version of this article was previously published by Burges Salmon on 10 March.
Cathryn Tracey is a partner at Burges Salmon
Contact Cathryn: Email
Related competencies include: Development appraisals, Environmental assessment, Planning and development management, Management and regeneration of the built environment
Discover the new RICS Member App: CPD on the go
RICS has introduced a refreshed CPD approach that prioritises meaningful, high-quality learning that genuinely benefits your work and is tailored to your specialism, career stage, and the real-world challenges you face.
The new app makes logging CPD simpler and more intuitive, so you can focus on the development that matters to your practice.
