Environmental Noise Impact Assessment - Guidance

Version 1.0 November 2024

Environmental Protection Advice Note 1 (EPAN 1):

‘Environmental Noise Impact Assessment - Fundamental Information To Be Reported In A Noise Impact Assessment (NIA) To Support A Planning Application’

Compiled By: Environmental Protection Unit, City And Neighbourhood Services Department

This Environmental Protection Advice Note (EPAN) sets out a framework of the minimum information required by the Environmental Protection Unit within Environmental Health to be included in a Noise Impact Assessment (NIA) to support a planning application.  The Advice Note is aimed at promoting a consistent standard of assessment information submitted by noise consultants. This document should be used as a checklist by noise consultants and planning agents before submission of any NIA reports to the Planning Service.

Where all necessary information is not provided as listed below, or a suitable rationale provided, Environmental Health will provide a brief response to the Planning Service advising that insufficient information has been provided. In responding, this Service will refer to the Advice Note identifying which aspects it is considered there is insufficient information provided.

Annex 1 of this EPAN lists national and international documents providing technical noise advice and guidance which the acoustic consultant may wish to consider relevant to a particular noise assessment. The list is not exhaustive, and consultants shall always be cognisant of updates and revisions.

An Environmental Noise Impact Assessment shall include:

1. Title or cover page – shall include a date and project or job number / reference. Details of consultant’s relevant acoustic qualification(s) should be provided as demonstration of competency.
2. Numbered pages - for ease of reference, along with numbered tables and figures.
3. Brief Executive Summary 
4. Introduction – description of the proposal and confirmation if the proposal is considered as noise sensitive, potentially noise generating or a mix of both with a description of the locality.
5. Site location - A site location drawing including: -

1. the red line boundary of the development
2. the most up-to-date version of the proposed site layout.

6. Site context and reporting details-

• List all existing noise sources in the area with potential to generate noise and impact the development with distances clearly reported/identified.
• If the development proposal has the potential to generate noise, identify all potentially affected noise sensitive receptors, with distances clearly reported or identified, this may include other premises as well as residential.
• Confirmation of operational days and hours associated with the existing nearby noise generating sources and/or any proposed sources associated with the development.
• The assessment, while determining the impact associated with existing noise generating sources and/or impact upon receptors, must also identify and consider any vacant premises, committed developments and pending planning determinations (where possible, confirm the planning status of these developments).

7. Summary of relevant noise guidance and standards – brief reporting of the list of noise standards / guidance that apply.  Justification/explanation should be provided as to why a particular standard or guidance is applicable to the assessment. More than one set of guidance or standards may apply to a NIA. The consultant is referred to the list of guidance/standards at the end of this document (Annex 1).
8. Baseline noise monitoring location – confirmation of the location of any noise monitoring points marked on a map, with contextual photographs of the sound level meter set-up in situ showing the meter location, height etc. There should be justification as to how the monitoring and associated results are representative in relation to the proposed development location and context. There should also be an explanation any measurement limitations and/or a justification of any measurement corrections applied e.g., use of proxy locations.
9. Representative baseline measurement survey –

1. times and days of the week as well as the duration of measurement shall be conducted over a suitably representative period and during times that reflect the proposed development and/or the potential impact.. For example, if a proposal will introduce floodlighting to an artificial grass pitch to extend use into the evening, then baseline measurements should include the extended operational hours for which the floodlighting will facilitate.
2. short-duration noise measurements, if presented in the assessment, shall be accompanied by a clear rationale and justification why the data is deemed representative of the noise climate of an area and/or of the assessment of source noise.
3. detailed subjective commentary shall accompany any attended short-term measurements.
4. unattended longer-term monitoring shall also include commentary and subjective notes of the noise climate as witnessed at equipment set-up and take-down.
5. consider the use of audio logging for unattended noise monitoring to facilitate subjective commentary as well as identification and comment of any suspected extraneous noise events.

10. Measurement data –

1. present a graphical or tabular summary of the noise measurement data in the body of the noise assessment report.
2. all raw measurement data recorded must also be included for completeness and transparency within an appendix. 
3. sound level meters and associated software should be capable of measuring and reporting the LAFmax in shorter 2minute intervals as per the method stipulated in the Association of Noise Consultants – Guide to Demonstrating Compliance with the Noise Requirements of Approved Document O July 2022 v1.0 (4.3.2.7) for assessing night-time impact.

11. Weather information –

1. details of weather conditions shall be reported for all assessments and any data excluded shall be highlighted and included in the report for transparency.
2. extended unattended noise monitoring should ideally include deployment of a weather kit for continuous logging of rainfall and wind speed with measured noise levels.
3. Use of a handheld anemometer may be acceptable for shorter term measurements.

12. Noise sources – all data presented for noise generating sources shall be robustly referenced and shall be reported either ‘as measured’ and /or ‘reference the library source level’. A clear distinction should be made between the use of Sound Power Levels and Sound Pressure Levels (including distance from source) in the assessment.
13. Prediction of impact –

1. the NIA should discuss the significance of the effect of predicted noise levels against the baseline noise climate and noise target criteria deemed relevant to the assessment.
2. the potential for cumulative noise impacts shall be included in the assessment, for example, an additional proposed 3G pitch close to extant approved pitch/es. 
3. significance of impact shall consider not only noise limits suggested in guidance, but in reaching conclusions regarding the significance of effect, shall also consider the magnitude of any change in noise levels as well as the times of the day, duration, frequency of occurrence, and particularly the nature/character of any new noise, including spectral characteristics.
4. consideration of each category of penalty with regard to BS4142:2014 assessments shall be robustly supported with data and / or measurements and a rationale provided including and, in particular, where the assessment concludes some or no penalties are necessary.
5. where the proposal has the potential to generate noise, the worst-case noise levels should be used in the prediction of impacts.

14. Assumptions – shall be declared in the report.
15. Assumptions regarding the sound reduction performance of existing structures/construction materials should be avoided. In the absence of accurate design detail or other means of evidence (e.g. photographs confirming floor/ceiling construction on inspection), conservative Sound Reduction Index (SRI) values should be used to ensure a robust assessment.
16. Calculations – full workings and origins and applicability of formulae used shall be presented.
17. Uncertainty – all noise assessments should consider the potential for uncertainty and factor in corrections for uncertainty particularly where assumptions have been used.
18. Noise Mitigation Section - the NIA shall include a dedicated section clearly summarising the specific mitigation measures deemed necessary. Physical mitigation measures, such as acoustic barriers, may also need to be depicted on drawings and submitted to Planning Service for review and approval. Having a clear dedicated ‘mitigation section’ within or at the end of a NIA allows for ease of interpretation by a developer and allows for a condition suggested to Planning Service which is precise, enforceable, necessary, and relevant to the development.
19. Appendices – site photographs to include measurement location, full measurement data, proposed development site layout, manufacturers’ noise data sheets, calibration certificates,  noise model outputs etc.

A note on noise modelling

20. Noise Modelling –where used, please provide the following information -

1. Noise modelling software used – version etc.
2. Calculation method used e.g., CRTN, DMRB, ISO9613 (1/3 octave etc.)
3. Indices being derived e.g., LAeq,16 hour, LAeq,8hour (Night), Lden, Levening, Lnight, Lmax advising of any weightings, penalties or corrections.
4. Receptor locations and grid height (heights).
5. Source input tables (octave band data, 1/3 octave data where deemed applicable) for point, line and area sources, any on/off corrections applied and reference to the origin and applicability of data source levels used.
6. Barrier heights, acoustic mitigation performance data and/or any assumptions made.
7. Environmental conditions e.g., ground conditions and prevailing wind direction.  Noise model output maps including a colour coded ‘key’ of the noise level contours displayed.
8. details on any ambient environmental noise sources used to calibrate the model (back calibration). Where any measured noise level is used to calibrate the model, care should be taken to identify and input the type and location of all sources involved.
9. identify and, where possible, isolate the measurement and rating of any extant plant and machinery (cross referenced to point h above).
10. this Service may request a copy of the model produced (typically in .QSI format).

Annex 1

Note: The following national and international documents provide technical advice and guidance which should be referred to within the noise assessment report.. The list below, however, is not exhaustive and other standards may apply.

In addition to the above standards, this Service would suggest the following research papers may prove useful in terms of identifying / determining suitable noise source levels:

 (Prediction of Noise from Small to Medium Sized Crowds (Haynes, Proceedings of Acoustics, Paper 133, 2011) – Lazarus 1986 vocal noise levels.

Carrying Out Noise Assessments for Proposed Childcare Centres (Scannell, Harwood - New Zealand Acoustics, Vol 20/#3).

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