BS8233 Noise Survey & Assessment: A Practical Guide to BS8233 Noise Assessments and Planning Permission

Posted in Acoustic Consultants News on Apr 05, 2019

BS8233:2014 set’s out appropriate internal and external noise levels for Bedrooms, Living Rooms, Dining Rooms and Gardens for the day time (07:00 – 23:00) and night time (23:00 – 07:00). It also provides guidance on the design of sound insulation for buildings and methods of achieving appropriate noise reduction for new build dwellings and refurbished dwellings undergoing change of use.

Why do you need a BS8233 noise assessment? 

When developing a residential house or flat, schools, healthcare facilities or hotels, if the development site is near to a transport noise source such as a road or railway then it is likely that during the planning permission process the Local Authority will request a BS8233 noise survey to be undertaken to ensure that appropriate internal and external noise levels can be achieved to guarantee the amenity of the future occupants. 

A BS8233 noise report can be requested at the pre-application stage of planning permission, if the Local Authority considers noise to be a high enough risk to affect the likelihood of the planning application being accepted. Or it may be conditioned under the planning permission approval. The information submitted within a noise survey report allows the Planning and Environmental Health Departments to assess the level of noise impact expected on the development and ensure appropriate protection measures are put in to place.

Ultimately, the purpose of the BS8233 noise survey is to ensure that the development is compliant with the National Planning and Policy Framework and Noise Policy Statement for England.

Typical Planning Conditions? 

Here are some examples of typical planning conditions that relate to BS8233:2014:

Example 1: No development shall commence until details of a noise assessment have been submitted to and approved in writing by the Council. The report shall include details of noise attenuation measures required to meet the standard for internal noise levels defined in table 4 of BS8233:2014 (including glazing and ventilation details). The dwelling hereby permitted shall not be occupied until the noise mitigation measures have been provided in accordance with the approved details and shall thereafter in retained in perpetuity.

Example 2: Prior to the commencement of the development, an environmental noise assessment and sound insulation scheme shall be submitted to and be approved in writing by the Local Planning Authority. The environmental noise assessment shall include the impact of any transportation noise, noise from people on the street and be carried out whilst any premises and/or activities in the vicinity that are likely to have an adverse effect on noise levels are operating. In addition, it shall include predicted noise levels for any plant and equipment which will form part of the development, octave band analysis and all assumptions made (e.g.glazing and façade areas).

The sound insulation scheme shall include the specification and acoustic data sheets for glazed areas of the development and any complementary acoustic ventilation scheme and be designed to achieve the following internal noise levels:

• Not exceeding 30dB LAeq(1 hour) and not exceeding NR 25 in bedrooms for any hourbetween 23.00 and 07.00,
• Not exceeding 35dB LAeq(1 hour) and not exceeding NR 30 for bedrooms and living rooms for any hour between 07.00 and 23.00,
• Not more than 45dB LAmax(5 min) in bedrooms (measured with F time weighting) between the hours of 23.00 and 07.00,
• Not more than 50dB LAeq(1 hour) for garden areas (including garden areas associated with residential homes or similar properties).

Example 3: No residential conversion works shall take place until a detailed acoustic report on the existing noise climate at the development site has been submitted to and been approved in writing by the local planning authority. If required, the report shall include a scheme of noise insulation measures for all residential accommodation. The noise insulation measures shall be designed to achieve noise insulation to a standard that nuisance will not be caused to the occupiers of residential accommodation by noise. The noise assessment shall be carried out by a suitably qualified acoustic consultant/engineer andshall take into account the provisions of BS4142:2014 and BS8233: 2014. The Approved scheme shall be implemented prior to the first occupation of any residential unit and be permanently maintained thereafter.

How is a BS8233 noise survey conducted? 

The aim of a noise survey is to gain a baseline measurement of the noise environment within the vicinity of your proposed development. Once the noise environment has been defined, the potential noise impact on residential dwellings can be assessed. The level of noise impact is analysed according toBS8233:2014 to ensure the future occupants will not be adversely affected by noise.

• We will carry out an environmental noise measurements and acoustic calculations to establish the noise levels across the development site.
• We recommend and assess appropriate mitigation measures to protect the external areas.
• We will calculate the internal noise levels to allow the provision of appropriate glazing and ventilation specifications for the development.
• We will provide a technical report for submission to your local authority to support your planning application

What will be in the technical report? 

The purpose of the technical report is to concisely outline to the Local Authority how ‘Good Acoustic Design’ has been implemented in the design of the development to ensure appropriate control measures are being installed. The noise survey report will outline the following:

• A statement outlining the purpose and objectives of the report
• A detailed review of the proposed development
• A description of the surrounding area and the noise sources incident on site
• The method that has been applied to assess the noise incident on site, including monitoring locations, the equipment used, calibration details, a weather summary and when the survey was conducted
• A summary of the results pertinent to the survey which typically include, L_Aeq,t, L_AMax,T, L_A90, L_A10 and 1/1 octave L_Zeq,t.
• A assessment of the noise level results in accordance with the relevant British Standards
• Recommendations and Mitigations measures required to protect the amenity of the future occupants including calculations of the expected noise reduction from the sound insulation scheme.

What Recommendations and Mitigations measures can be expected from your noise report?

The report will aim to apply all reasonable noise control measures to ensure the internal and external noise requirements of BS8233:2014 can be achieved. It is always preferable for noise to be controlled at source, however this is not always feasible. The following mitigations measures can be applied:

• Distance Separation
• Building Orientation
• Screening and Acoustic Barriers
• Building Layout and Design
• Sound Insulation Schemes
• Acoustic Glazing and Doors
• Alternative Ventilation Strategies

What do you need to do? 

Once you have had your BS8233 noise survey completed and received your technical report, you will need to review the recommendations and ensure any amendments to the design of the development are clearly outlined in your site layouts, detailed plans and any other supporting documents. The report will need to be sent to the council for approval, which should be received in writing.

Following this, the responsibility then falls on the developer to ensure all the recommendations and mitigations measures are installed. Quality control and workmanship can have a huge impact on the adequate performance of noise control measures, so it is imperative to have a high standard of workmanship to ensure the correct execution of the acoustic detailing recommended.

How can we help?

We listen to our clients’ needs and present them with practical, cost-effective solutions. This means that we offer a truly bespoke acoustic consultancy service for prices that are considered among the most competitive in the industry. NOVA Acoustics Ltd places a team of highly skilled, qualified and experienced acoustic consultants at our client’s full disposable; this is combined with the latest equipment, technological insights and expert guidance and recommendation, to ensure that clients are getting a guaranteed quality service every time they decide to get in touch.

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