Net benefit for biodiversity in Wales and the section 6 duty

This article is about Wales. Net benefit for biodiversity in Wales is a policy requirement in Planning Policy Wales, backed by a statutory duty on public authorities under section 6 of the Environment (Wales) Act 2016, and it is not the English mandatory net gain regime with a different name. There is no statutory percentage, no statutory metric and no biodiversity gain condition deemed into Welsh permissions. What there is instead is a duty on public authorities to support biodiversity and the resilience of ecosystems, a policy test that development must deliver a net benefit, and a stepwise approach that can end in refusal.

The statutory duty on public authorities

Section 6 of the 2016 Act requires public authorities in Wales to seek to maintain and enhance biodiversity so far as is consistent with the proper exercise of their functions, and in doing so to promote the resilience of ecosystems. The duty replaced the earlier conservation duty that still applies in England.

Two features make it bite harder than a background obligation. The duty refers to resilience, which Natural Resources Wales assesses through diversity, extent, condition, connectivity and adaptability, so an authority is expected to think about ecological networks rather than only about designated sites. And authorities must publish a plan setting out what they will do to comply and report on it, which gives objectors and applicants a document to quote.

Section 7 of the same Act carries the lists of living organisms and habitats of principal importance for maintaining and enhancing biodiversity in Wales. Those lists are the practical starting point for identifying what a site holds that matters.

Net benefit against mandatory net gain

The differences are worth setting out plainly, because agents working across the border get caught by them.

The absence of a metric cuts both ways. It removes the arithmetic argument about units, which in England now consumes a great deal of fee time. It also removes the certainty, so a Welsh authority's judgement about whether a scheme delivers a benefit is harder to predict and harder to appeal.

Some Welsh authorities ask applicants to use a metric voluntarily as supporting evidence. Treat that as a presentational aid rather than the test.

The stepwise approach applied in Wales

Planning Policy Wales sets out a stepwise approach to biodiversity and resilience. In order: avoid harm, then minimise it, then mitigate what cannot be minimised, then as a last resort compensate. Only after that is the question of enhancement reached, and the policy position is that where harm cannot be avoided, minimised, mitigated or compensated, permission should be refused.

That ordering matters for how an application is assembled. A scheme that leads with an attractive enhancement package while leaving an avoidable loss of semi-natural grassland in the layout has not answered the first step. Officers in Wales read the steps in order.

So the ecological appraisal needs to document the alternatives considered and show why the retained habitat could not be retained in full. That record is the evidence for step one, and without it the stepwise approach collapses into an assertion.

Evidence a Welsh authority expects

The documents that carry these applications are familiar, but their emphasis differs. A Preliminary Ecological Appraisal establishes what the site holds, mapped against the section 7 lists and the local ecological network. Species surveys follow where the appraisal identifies a reasonable likelihood of protected species, with the same seasonal windows as in England.

Then the net benefit case itself: what is lost, what is retained, what is created or restored, how it connects to habitat beyond the site boundary, and how long it will be managed and monitored. Connectivity is given more weight in Wales than applicants expect, because resilience is written into the duty.

Bear in mind that PlanScope's drafting is grounded in English national policy and English local plans. For a Welsh site, the structure of a report such as a Biodiversity Net Gain Assessment is still useful as a framework, but the policy citations and the legal framework need replacing with Welsh sources, and an ecologist has to make the ecological judgements. The devolved systems diverge on procedure as well as policy, as our notes on the two-tier system in Northern Ireland and the hierarchy of developments in Scotland show.

Securing enhancement by condition

Because there is no deemed condition, the enhancement has to be secured by ordinary means: a condition requiring a landscape and ecological management plan, a condition tying implementation to a phase of the development, or a planning obligation for longer term management and for anything off site.

Draft the condition so that it has a measurable end point. A requirement to deliver "ecological enhancement" is unenforceable. A requirement to implement an approved management plan, with specified habitat areas, a planting specification, a management schedule and monitoring reports at stated intervals, is enforceable.

Where the enhancement depends on land outside the application site, an obligation is the right instrument, and the land has to be controlled. Check title and tenancies before committing to it in the application.

Where applicants go wrong

Four failures recur. Treating net benefit as a tick box answered by a bird box schedule. Skipping the avoidance step and offering compensation instead. Submitting an English metric output as though it answered the Welsh policy test. And leaving the ecological appraisal until the layout is fixed, which makes avoidance impossible by definition.

The fix for all four is the same, and it is dull. Commission the appraisal before the layout is drawn, let the ecologist mark the parcels to keep, design around them, and then write the net benefit case from what the design actually does. Schemes assembled that way read as coherent and they survive consultation with Natural Resources Wales.

A fifth point is worth noting. Welsh Government has considered introducing a more prescriptive approach to biodiversity in planning, so the position may change. Check the current edition of Planning Policy Wales and the current Technical Advice Note before relying on the framework described here.

This is general guidance on the Welsh planning system, not legal advice. Check the position with the local planning authority or a qualified professional before relying on it.

Browse the report types to see which ecology documents a scheme is likely to need, then have the policy framework checked against Welsh sources before submission.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.