Northern Ireland wind turbine noise guidance replaces ETSU-R-97

Northern Ireland wind turbine noise guidance has changed after the Department for Infrastructure confirmed that a new UK assessment framework will replace ETSU-R-97 in planning applications and appeals.

The Northern Ireland wind turbine noise guidance decision, published on 1st October 2026, applies across Northern Ireland. Councils, DfI, the Planning Appeals Commission, environmental health officers, applicants and agents are now expected to use the Assessment and Rating of Wind Turbine Noise guidance, known as ARWTN.

This is a technical guidance change rather than new legislation. ARWTN is a material consideration, not an automatic route to approval or refusal, but it changes the evidence and methodology expected when operational wind-turbine noise is assessed.

DfI adopts Northern Ireland wind turbine noise guidance

The Department published a Section 75 screening analysis recording its decision to apply ARWTN within Northern Ireland’s planning system. The underlying technical document was issued by the Department for Energy Security and Net Zero on 19th June 2026 for use across the four UK nations, but the 1st October document is DfI’s formal statement of how it will operate in Northern Ireland.

DfI says the revised approach provides “a robust and proportionate framework”. Its screening records a new departmental decision to apply the revised guidance within Northern Ireland. That distinction matters because planning is devolved. A UK department produced the technical methodology, while the Northern Ireland department has now confirmed its status in the regional planning system.

The guidance addresses operational noise from individual wind turbines and wind farms, excluding turbines allowed under permitted development rights. Construction, decommissioning and noise from related infrastructure fall outside its scope. It provides assessment, monitoring and compliance methods and includes an example planning condition.

ARWTN does not decide whether a wind-energy development is acceptable. DfI says it must be considered with the local development plan, environmental information, consultation responses, public representations and every other relevant material consideration.

ETSU-R-97 references now mean the updated guidance

ETSU-R-97, The Assessment and Rating of Noise from Wind Farms, had been used since 1996. Paragraph 6.234 of Northern Ireland’s Strategic Planning Policy Statement, Edition 2, identifies it as the UK standard methodology and says it should be used with associated Institute of Acoustics guidance.

However, footnote 58 anticipated a later replacement. It says references to ETSU-R-97 should include any future update to the UK standard or its associated guidance. DfI has now confirmed that references to ETSU-R-97 in Northern Ireland planning policy and guidance are to be interpreted as references to ARWTN.

That means an applicant cannot safely rely on an assessment prepared solely around the superseded document without checking it against the updated methodology. The same issue arises for councils and the Planning Appeals Commission when considering current evidence or determining appeals.

The change does not reopen every permission previously granted using ETSU-R-97. It affects the assessment of live and future proposals, and the weight to be given to evidence remains a matter for the decision-maker in the circumstances of each case.

What has changed in the noise assessment framework?

The new document is a targeted technical update rather than a wholesale reversal of the previous approach. It reflects changes in turbine technology, measurement methods and professional practice during the three decades since ETSU-R-97 was issued.

The Institute of Acoustics says the underlying noise limits have not changed and the general assessment principles remain similar. The important changes lie in updated terminology, clarification of assessment practice and a more explicit treatment of issues that have developed through professional guidance.

DfI’s screening analysis highlights methodologies for assessment, monitoring and compliance. The revised guidance also updates the treatment of amplitude modulation, the characteristic variation in turbine noise that can produce a recurring swishing or thumping effect.

It formally draws established Institute of Acoustics good practice into the framework. Until replacement material is issued, the Institute advises practitioners to continue using its 2013 Good Practice Guide and the six 2014 supplementary guidance notes alongside ARWTN.

Those notes cover data collection, data processing, sound-power data, wind shear, post-completion measurements and noise propagation over water. The practical task is therefore not merely to change the name on a report. Noise consultants will need to show that the evidence and analysis follow the current combined framework.

Guidance is material but not determinative

DfI is explicit about the status of the Northern Ireland wind turbine noise guidance and ARWTN. It is voluntary best-practice guidance and one material consideration within the planning balance. It does not allocate sites, grant planning permission or remove the need to examine landscape, ecology, residential amenity, public safety and other effects.

Planning authorities retain responsibility for deciding what weight the updated evidence deserves. A technically compliant noise report does not establish that the wider proposal is acceptable, while an objection cannot succeed merely by referring to the existence of the new guidance without engaging with the assessment.

The normal procedural safeguards remain. Statutory consultation, neighbour notification, advertisement and opportunities to make representations are not altered by DfI’s decision.

For an overview of how noise evidence is handled more generally, see Planning Geek’s noise in planning applications guide. The Northern Ireland decision is jurisdiction-specific, although the ARWTN technical document was written for use throughout the UK.

Implications for current applications and appeals

Applicants working under the Northern Ireland wind turbine noise guidance should check when their acoustic work was prepared and whether it already anticipates ARWTN. Where a report uses ETSU-R-97 terminology or methods, the planning authority may need an addendum explaining whether the conclusions remain valid under the replacement guidance.

Councils should avoid treating every older assessment as automatically defective. The Institute of Acoustics has emphasised the continuity in limits and core principles. The proportionate question is whether the submitted material supplies the information needed under the current framework and whether any difference could affect the planning judgement.

The Planning Appeals Commission is among the bodies DfI identifies as expected to use the guidance. Appeal statements and expert evidence should therefore address ARWTN directly, particularly where noise was a reason for refusal or a disputed condition.

Existing draft conditions also need checking. ARWTN includes an example condition, but conditions must still be necessary, relevant, enforceable, precise and reasonable for the individual development. A standard clause should not be inserted without adapting it to the permission and the evidence before the authority.

Residents and community groups need evidence tied to ARWTN

For neighbours, the Northern Ireland wind turbine noise guidance offers a clearer route for testing an applicant’s assessment. Representations are likely to carry more weight where they identify a specific omission, disputed assumption, receptor or compliance concern under the current methodology.

General opposition to turbines, or a claim that any audible noise is unacceptable, will not replace technical evidence. Equally, compliance with a numerical limit does not prevent residents raising site-specific matters that remain relevant to amenity and the planning balance.

DfI says the updated framework aims to protect neighbouring communities from adverse noise effects while supporting renewable-energy deployment. It found no evidence that applying the guidance would adversely affect a Section 75 equality category and did not recommend a full equality impact assessment.

Northern Ireland policy remains separate from the English system

The Northern Ireland wind turbine noise guidance uses a technical document produced for the UK, but the policy route giving it planning weight differs between nations. DfI’s publication concerns Northern Ireland only and should not be described as an MHCLG change or an amendment to England’s National Planning Policy Framework.

Northern Ireland’s two-tier system divides responsibilities between DfI and the 11 councils. DfI controls regional policy and determines regionally significant and called-in applications, while councils prepare local development plans and determine most applications.

The department’s separate 1st October update to its renewable and low-carbon energy policy screening reinforces the same point: SPPS references to ETSU-R-97 are intended to be read as the replacement guidance. The revised renewable-energy policy itself was published and took effect on 11th December 2025; the October 2026 material is an implementation clarification, not a fresh launch of SPPS Edition 2.

Documents and next steps

Read the Northern Ireland decision document hosted on Planning Geek alongside DfI’s official publication. The ARWTN technical guidance is also hosted locally, with the official GOV.UK source retained.

The Northern Ireland wind turbine noise guidance means applicants, councils and appeal parties should now audit live noise evidence, report instructions and proposed conditions against ARWTN. Where an acoustician is required, Planning Geek can advise on the planning case and coordinate with an appropriately qualified noise specialist, but does not provide acoustic engineering services.

The immediate practical message is straightforward. ETSU-R-97 remains important history, but it is no longer the operative technical document. DfI’s publication on 1st October 2026 confirms that Northern Ireland decision-makers should use the replacement framework.