Pre-completion sound testing is the on-site acoustic measurement required to demonstrate that a new residential building or conversion meets Part E of the Building Regulations before it can be occupied. Tests measure airborne sound insulation (through walls and floors) and impact sound insulation (through floors). The pass thresholds for new builds are DnT,w + Ctr ≥ 45 dB for airborne sound and L'nT,w ≤ 62 dB for impact sound; for conversions, 43 dB and 64 dB respectively. Testing must be carried out by an accredited body: NOVA Acoustics holds UKAS accreditation (No. 8568) for sound insulation testing. If a test fails, building control sign-off cannot be granted until remediation is completed and a passing re-test is achieved.
Extraction System Noise Surveys & Assessments
What is an extraction system noise survey?
Extraction systems are among the most common noise nuisance complaints, especially in built-up areas where pubs and restaurants are located in close proximity to houses. The problems are exacerbated if commercial kitchen exhausts vent into small shared spaces or are located beneath residential units – flats and apartments situated above takeaways with late opening hours, for instance.
If catering businesses are located in busy city centres, extraction system noise levels may be indistinguishable from other ambient sounds, such as traffic and music systems. However, in quieter areas, they could be more intrusive and more likely to get a poor reception from neighbours. According to Amberth, a kitchen design company in London, thoughtful kitchen planning should consider not only workflow and ventilation performance but also how extraction systems may affect surrounding spaces. Acquiring accurate data on noise emissions is the only way to ensure your business complies with regulations designed to minimise noise nuisance. Assessing noise levels in context is crucial.
In order to be certain about the noise emissions from an extraction system, you need to commission a BS4142 noise survey. The official approach to rating and assessing any industrial or commercial noise is via British Standard BS 4142: 2014. This standard applies to sound assessment from fixed installations of mechanical and electrical plant and equipment, including extractor fan units.
Rather than assessing the absolute sound levels, the assessment method calculates the difference between the ‘background sound level’ and the ‘rating level’ of the industrial source, at the receiver location. The greater the difference between these two reference points, the bigger the impact on the immediate environment. The guidance for BS4142:2014 advises that a difference of circa 5dB+ could indicate adverse impact, while 10dB+ could indicate significant adverse impact.
How are extraction system noise surveys used?
Construction activities, though vital for societal progress, are often accompanied by high levels of noise that can disrupt the tranquility of surrounding areas. From jackhammering to heavy machinery operations, construction noise can affect nearby residences, schools, hospitals, and workplaces, leading to annoyance, sleep disturbances, and even long-term health issues.
Challenges in Monitoring Construction Noise
An extraction system noise survey is usually a requirement when a planning application is being submitted to a local authority. The requirement is as likely to apply to smaller catering businesses, such as cafes and hot food shops, as it is to large commercial kitchens and takeaways, such as KFC and Nandos. A noise impact assessment to BS 4142:2014 will satisfy the local planning authority that proposals will not have an adverse impact on others.
Our thorough extractions system noise survey include:
- Background sound level assessment
- Assessment of noise emissions from the extractor fan (or acoustic modelling if the unit is not yet operational)
- Analysis of noise impact to BS4142:2014
- Recommendations for any noise mitigation measures (including fitting a silencer)
- Technical report for submission in support of a planning application
We approach every case with fresh eyes and you can be confident with our in-depth understanding and experience dealing with local authorities to achieve planning permission for a range of client for extraction systems.
Should the proposed installation seem likely to cause adverse impact, we will provide you with tailored advice regarding cost-effective and realistic solutions that will enable you to meet BS 4142:2014 standards, including changing or modifying the proposed unit, re-orientation or realignment, or the implementation of acoustic noise-reducing barriers or enclosures.
Why choose Nova Acoustics?
NOVA Acoustics is one of the UK’s leading independent consultancies. We offer a dedicated, professional service to a wide range of private and commercial clients through a network of accredited engineers. We have extensive experience of conducting a wide range of noise surveys including BS 4142:2014 extractor fan noise surveys and can usually offer a fast turnaround on urgent projects. Our expert advice is highly valued.
- Leading independent consultancy
- Professional consulting team
- Practical and cost-effective advice
- Local accredited engineers
- CSCS safety approved
Recent posts
The National Planning Policy Framework requires planning authorities in England to consider noise as a material planning consideration. It does not set noise limits. Instead, it establishes the policy principles that govern when noise assessments are required, how significance is determined, and what mitigation is appropriate. The two most important principles for developers are the agent of change principle (the party introducing a noise-sensitive use near a noise source bears responsibility for managing the acoustic consequences), and the requirement to avoid placing noise-sensitive development in high-noise locations unless unacceptable impacts can be adequately mitigated. In practice, NPPF noise policy is implemented through technical standards including BS4142 and BS8233, and professional guidance including ProPG.
BS8233:2014 is the British Standard used to assess whether residential development near roads, railways, or other noise sources can achieve acceptable internal and external noise levels for future occupants. It sets out criteria for bedrooms, living rooms, and gardens across daytime and night-time periods. The most commonly referenced targets are 35 dB LAeq during the day and 30 dB LAeq at night for bedrooms. A BS8233 assessment is almost always required for residential planning applications in noise-sensitive locations, and is often conditioned by the local planning authority. ProPG (2017) sits alongside BS8233 and provides professional guidance on how assessments should be scoped and presented. This guide covers both.