Potentially Noisy Developments
22. Advice on the assessment of some sources of noise is provided below. Further advice on Noise Impact Assessment methodology and technical standards is contained in the Technical Advice Note.
23. Road traffic noise impact assessments should take account of level, potential vibration, disturbance and variation in noise levels throughout the day, the pattern of vehicle movements and the configuration of the road system. When upgrading existing roads it will normally be sufficient to base noise assessments on the current measured noise level. When considering proposals for the development or improvement of major roads, forecast noise levels can be ascertained from the relevant roads authority. In some cases, roads authorities may have prepared predictions of the effects of road traffic noise but this will depend upon accurate data on traffic flow being available.
24. Railway operators should have details of current traffic flows, and in some cases noise levels.
Civil and Military Aerodromes
25. Noise from aerodromes is likely to include activities such as engine testing and ground movements as well as aircraft landing and taking off. For major aerodromes, (LAeq16hr) is the conventional unit of measurement for planning purposes, although different metric are used in the END noise mapping process. Where land is subject to significant levels of aircraft noise, or is likely to become so, planning authorities should seek the co-operation of aerodrome management in reaching appropriate forecasts of air traffic and its effect on noise contours. The objective will be to achieve a clear and stable pattern of constraints against which planning decisions can be made.
26. Military jets can generate very high noise levels, particularly during take off, and occasionally the effectiveness of noise abatement flight procedures normally adopted may be limited by operational requirements. Changes in aircraft type and number of movements may also occur over a short period, resulting in unpredictable changes in noise levels. However, military flying is usually concentrated into weekday working hours when background noise and daytime activity render aircraft noise less intrusive. Where disturbance caused by military aircraft is likely to occur from take-off and landing outside the boundaries of the planning authority area, affected authorities should be consulted.
Helicopters and Heliports
27. Account should be taken of local circumstances, including the existing level of noise disturbance in the area surrounding the site and factors such as whether the area is already exposed to noise from fixed wing aircraft. Planning applications for heliports should be accompanied by information about the proposed take-off/landing flight paths, and air traffic routes where appropriate. Preferably, these paths should have been discussed and agreed in principle with National Air Traffic Services ( NATS) beforehand. Planning conditions relating to flight routes are likely to be inappropriate.
28. For safety reasons, helicopters may only operate from elevated sites such as flat roofs if given special approval by the Civil Aviation Authority. All of these movements can cause disturbance locally but may be incidental or ancillary to the principal use of the land or of a temporary nature and so do not require planning permission. Voluntary agreements may be an effective way of limiting disturbance in these cases .
29. There are two sources of noise from wind turbines - the mechanical noise from the turbines and the aerodynamic noise from the blades. Mechanical noise is related to engineering design. Aerodynamic noise varies with rotor design and wind speed, and is generally greatest at low speeds. Good acoustical design and siting of turbines is essential to minimise the potential to generate noise. Web based planning advice on renewable technologies for Onshore wind turbines provides advice on 'The Assessment and Rating of Noise from Wind Farms' ( ETSU-R-97) published by the former Department of Trade and Industry [ DTI] and the findings of the Salford University report into Aerodynamic Modulation of Wind Turbine Noise.
Other Renewable Energy Technologies
30. The noise and vibration characteristics of air source heat pumps may need to be considered. Other than in the circumstances set out by Circular 2/2010, planning permission continues to be required for air source heat pumps and noise assessments may be required to ensure that neighbours are not disturbed by their installation.
31. Due to its variable character industrial noise is generally difficult to assess. Since background noise levels vary throughout a 24 hour period it will usually be necessary for Noise Impact Assessments to assess the acceptability of noise levels for separate periods ( e.g. day, evening, night and weekend) chosen to suit the hours of operation of the proposed development. Noise that may result from traffic generated by new industrial developments is likely to be a relevant consideration.
Construction Sites32. While planning conditions can be used to limit noise from temporary construction sites, it is most effectively controlled through the Control of Pollution Act 1974 and the Pollution and Prevention Control Act 1999 for relevant installations. Notice can be served in advance of works and site conditions set to control activities.
Recreational and Sporting Venues
33. For these activities, including open-air music concerts, off-road motor vehicle activities, motor racing circuits, water sports and clay target shooting, NIAs should take account of how frequently the noise will be generated and how disturbing it will be and should demonstrate that the proposed activity does not have an adverse impact on nearby noise sensitive land uses. Partially open buildings such as stadia may not be in frequent use and depending on local circumstances and public opinion, it may be reasonable to permit higher noise levels than for other types of development, subject to a limit on the hours of use, and the control of noise (including public address systems) during unsociable hours. Some noisy activities may not require planning permission because they occur on a temporary basis. However, these permitted development rights can be removed through a direction under Article 4 of the Town and Country Planning (General Permitted Development) (Scotland) Order 1992.
34. For some entertainment venues authorities have imposed conditions on a planning consent which requires that noise resulting from a proposed development is inaudible in adjacent noise sensitive premises. If inaudibility is considered appropriate, it is important to note that monitoring of such conditions may not be straightforward, and conditions should always meet the tests set out in Circular 4/1998 Use of Conditions in Planning Permissions.
35. NIAs should address noise from vehicular movements, frequency of deliveries, tipping operations, site plant, hours of operation and the provision of acoustic screening as they will have indirect effects on the amount of noise generated. PPC permit conditions can control noise in existing landfill sites that are operating with the benefit of a Certificate of Lawful Use or a planning permission that does not contain a noise condition. See also PAN 50 Annex A - Surface Mineral Working.