On 19th June 2026 the UK Government published Assessment and Rating of Wind Turbine Noise (ARWTN) which should be used to assess operational wind farm noise in the UK going forward with immediate effect. The document supersedes ETSU-R-97 ‘The assessment and rating of noise from wind farms’ which has been used to assess wind farm noise in the UK since it was published in 1996.
Why are the updated wind turbine noise assessment guidelines important?
Operational noise can be a key constraint in the design of a wind farm, influencing the number and size of turbines that can be installed. Noise constraints can also impact operational sites, reducing the amount of energy that can be generated.
Robust noise guidance is key to ensuring that any impacts on local residents are properly assessed at the consenting stage and that noise can be controlled via appropriate planning conditions once a site becomes operational.
What are the key changes in the updated wind turbine noise assessment guidelines?
Whilst some elements of the updated guidance remain the same as ETSU-R-97, the main changes can be summarised as follows:
- A change in the criteria for how the daytime fixed minimum limit (now referred to as the ‘Lower Limiting Value’) should be determined
- Additional guidance on how site specific noise limits should be derived in cumulative scenarios
- Updates regarding how smaller turbines should be considered in cumulative assessments
- The inclusion of an example noise related planning condition which includes control of Amplitude Modulation
What has stayed the same in the updated wind turbine noise assessment guidelines?
Some key elements of the updated guidance remain the same as ETSU-R-97, these include:
- The aim to ensure a reasonable degree of protection for wind farm neighbours without placing unreasonable restrictions on wind farm development;
- Noise limits are set relative to background sound levels so baseline surveys are still required and their scope unchanged; and
- The application of fixed minimum limits between 35 and 40 dB during daytime periods and 43 dB at night, increasing to 45 dB with financial involvement.
What does this mean for my project?
The impact of the updated guidance on a specific project depends on various factors. There would be no impact on operational or consented sites which have noise limits derived in accordance with ETSU-R-97. These sites can continue to operate within the noise limits specified in their planning conditions.
For sites in planning or at the pre-planning stage the new wind turbine noise assessment guidance will apply. The impact of the new guidance will vary on a site-by-site basis depending on factors such as:
- The appropriate fixed minimum limit; and,
- Whether there are cumulative impacts.
How can TNEI help?
TNEI has undertaken noise assessments for more than 5 GW of onshore wind developments. TNEI was involved in the drafting of best practice guidance on the application of ETSU‑R‑97 and is part of the working group that is currently updating the best practice guidance to reflect the release of ‘Assessment and Rating of Wind Turbine Noise’.
Please get in touch should you wish TNEI to undertake a review of what the updated guidance means for your project or portfolio.
