Developments of National Significance in Wales explained

This article is about Wales. A Development of National Significance is a category of scheme that bypasses the local planning authority and is determined by Welsh Ministers instead. The regime was created by the Planning (Wales) Act 2015 and has no equivalent in England, where major infrastructure projects follow a different statute and a different consenting body. Applications are made to Planning and Environment Decisions Wales, which examines them and reports to Ministers.

For a developer, the attraction is that a DNS application can carry prescribed secondary consents with it, so one process delivers the planning permission and several of the other authorisations the scheme needs.

What qualifies as a Development of National Significance

The categories are set by Welsh regulations rather than by judgement, and the best known is energy generation above a defined output threshold. Other prescribed categories of infrastructure sit alongside it.

The thresholds and the list have been amended since the regime began, so confirm the current definition against the regulations before choosing a route. A scheme sitting close to a threshold needs care, because the consequence of getting it wrong is an application made to the wrong body.

Where a scheme falls below the threshold, it is a local application determined by the local planning authority in the ordinary way. There is no discretion to opt in, and no discretion for a council to push a large scheme up to Ministers because it would rather not decide it.

Where the application is made and who decides

Applications go to Planning and Environment Decisions Wales, the body that handles planning appeals and casework for the Welsh Government. It checks the application for acceptance, manages the examination, appoints an inspector and produces a report.

The decision is taken by Welsh Ministers, who are not bound to follow the inspector's recommendation. That is a real difference from an ordinary planning appeal, and applicants should present the case with the Ministers as the audience rather than only the inspector.

The local planning authority is a consultee rather than the decision maker, and it prepares a local impact report setting out the effects of the scheme on its area. That report carries weight, so engaging with the authority early remains worthwhile even though it no longer decides.

Secondary consents bundled with the application

The distinctive feature of the regime is the treatment of secondary consents. An applicant may apply for prescribed secondary consents at the same time as the DNS application, and Welsh Ministers determine them together.

The categories are prescribed in regulations and typically cover consents that would otherwise be sought separately from the local authority or another body. Bundling them removes the risk of a permission granted while a related consent sits unresolved.

Two practical points. The secondary consent applications have to be prepared to the same standard and submitted at the same time, which front-loads the work. And bundling is optional, so an applicant can choose to pursue a consent separately where the timing suits.

Decide the bundling strategy before the pre-application consultation starts, because the documents published at that stage should cover everything being applied for.

The examination process and its timetable

The regime is timetabled, with periods set in regulations for acceptance, for the local impact report, for representations and for the examination itself. That predictability is one of its selling points.

Examination is normally by written representations, with hearings held where the inspector considers them necessary. The inspector sets the matters to be examined and may ask written questions.

Keep the programme honest with the client. The timetable is predictable, and it is not short, and the pre-application work that precedes it is substantial.

Resource the examination properly. Written questions arrive with short deadlines, and a team that has moved on to the next project will struggle to answer them well. Hold the authors of the technical documents available until the examination closes.

Evidence expectations for a DNS submission

The evidence base is closer to that of a major infrastructure project than to a local application. Expect a full environmental assessment where the development requires it, with an Environmental Impact Assessment prepared by competent experts under the relevant regulations, because the Welsh EIA regime applies in the ordinary way.

Alongside it, the submission needs a policy case tested against Planning Policy Wales, the relevant Technical Advice Notes and Future Wales, plus the development plan for the area. The Planning Statement should address national policy first, because that is the level at which Ministers decide.

Community engagement evidence matters more than in a local application, not less. The statutory pre-application consultation applies, and the record of it feeds the examination directly, in much the same way a Statement of Community Involvement supports a major scheme elsewhere.

Local authority and community roles

Councils, community councils and residents all take part, and the regime is designed to give them a route in despite the decision sitting with Ministers.

The local authority's local impact report is the formal channel and the most influential. Community councils and individuals make representations during the prescribed period, and the inspector considers them.

Timing is tight for councils. Preparing a local impact report on a large scheme takes officer time that a planning department has not budgeted for, and the deadline does not move. Authorities that start work at the pre-application consultation stage produce better reports than those that wait for the application to be accepted.

There is a common misunderstanding worth correcting. Losing the local decision does not mean losing local influence. Ministers read the local impact report, and an authority that sets out measurable harms and workable remedies is taken seriously. A well-evidenced local impact report identifying specific harms and proposing conditions or obligations frequently shapes the outcome more than an objection campaign.

Choosing between the DNS route and a local application

Where the scheme clearly meets a threshold there is no choice. Where it sits near one, the design decisions that push it over or keep it under deserve deliberate thought rather than accident. Output capacity, site area and the inclusion or exclusion of ancillary elements are the usual variables, and they should be settled at feasibility stage rather than during document preparation.

The DNS route offers a timetabled process, a single decision maker and the option of bundling consents. It costs more to prepare, engages national policy directly, and removes the local relationship that can help a marginal scheme. A local application costs less to prepare and is less predictable in timing.

PlanScope's drafting is grounded in English national policy and English local plans, so any Welsh submission needs the reviewer to substitute Planning Policy Wales, Future Wales and the Welsh procedural requirements. For a DNS that check is substantial, and it belongs with a Welsh planning professional.

Browse the report types on PlanScope to see what a major infrastructure submission usually includes.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.