Assessment of noise: technical advice note

Chapter 4: Mitigation

4.1 There are various ways to control noise or limit people's exposure to it through design. These design measures should be the minimum necessary and may include one or more of the following:

• Engineering and building design;
• reducing noise at its point of generation, for example by using quiet machines and quiet methods of working;
• containing noise, for example by insulating buildings which house machinery and providing purpose-built barriers around a site;
• protecting noise-sensitive buildings and areas, for example by improving sound insulation in these buildings and screening them with purpose-designed acoustic barriers;
• Layout design: for example, adequate distance between source and noise-sensitive building or area; screening by natural barriers, other buildings, or non-critical rooms ( e.g. garages or bathrooms) or elevations of a building;
• Management design: for example, specifying an acceptable noise-limit, limiting operating time of source or restricting activities allowed on the site.

4.2 Examples of good practice in relation to the mitigation of noise as far as it affects the design and layout of residential development is contained within Sound Control for Homes ( BRE/ CIRIA, 1993, ISBN 085125-559-0).

4.3 Early discussion between developers and noise consultants about design and mitigation measures is desirable and may enable them to be incorporated before the application is submitted. Addressing noise issues early in the design process is usually more cost effective and less disruptive than inserting measures late in the design process or taking remedial action in a completed project. Strategic decisions relating to site planning, built form and materials can all dramatically influence noise control matters without having cost implications providing these choices are exercised early enough. Limiting the adverse effects of noise by engineering and layout design is usually to be preferred rather than controlling noise through measures such as restricting hours of operation, which could undermine the economic efficiency and operational capacity of a business or enterprise.