Managing noise in our densely populated cities
As our cities continue to expand with more people, traffic, construction and industry, noise pollution has become a major concern. Peter Jackson, managing director at Jacksons Fencing, looks at what to consider when reducing the unwanted noise from inevitable construction.
The UK had more than 65 million inhabitants at the start of 2016, with a density of 263 people per square kilometre.
As our cities expand – the population is projected to reach 77 million by 2050 – commercial, retail and leisure developments and critical infrastructure like roads and rail need to develop to cope with the growth.
Such a concentration of people, construction activity and transport hubs brings noise that in many cases is unwanted, yet avoidable.
Noise pollution causes people stress, fatigue and poor quality of sleep costs $750bn globally when medical bills, lost earnings and other hearing loss-related problems are accounted for.
When it comes to acceptable noise levels, the general guide is that daytime outdoor sound should be lower than 50dB.
The World Health Organisation recommends levels to “mimic” the sensitivity of the human ear to different frequencies. For example, a pneumatic drill some 15 metres way is moderately loud at 80dB compared to light vehicle traffic of 50dB.
Reducing unnecessary noise while improving or maintaining the look of the surrounding space is a challenge for many city planners, architects, developers and builders. Ensuring that retail or housing developments are well screened from road traffic or railway noise can be an issue, since transport hub perimeters must be secure and functional.
The Department for Communities and Local Government’s National Planning Policy Framework sets out the requirements for planning for local people and accountable councils to take into consideration.
Noise is included in the framework, so avoidance and minimising impact on health and safety due to noise therefore plays an important part in local planning decisions.
Due to the complex nature of sound, it is never a case of “one size fits all” – the length, height, type and location of barrier required will always be determined by the type of construction taking place.
Below is a brief guideline of what to consider when specifying fencing to limit noise from a construction project:
- Material density – the barrier should be of sufficient mass to reflect noise;
- Barrier installation – prevents noise penetration by ensuring there are no air gaps;
- Barrier height – the barrier should also be sealed to the ground to prevent noise creeping underneath;
- Distance from noise source to receiver – the barrier should be located as close as possible to the noise source.
The protective solution not only needs to be practical, it has to be visually appealing, in order to attract residents, shoppers and businesses. Timber can provide a natural facade that is ideal for the modern cityscape.
Acting as a barrier reflecting noise, timber solutions available today use heavy section planed interlocking timber boards, which eliminate gaps that sound can easily travel through.
Timber solutions installed this way can reduce noise by up to 28dB (under laboratory conditions) making it ideal for a range of applications. But, timber not only delivers good noise reduction performance and security, it also answers demands for an aesthetic solution that blends in with the surrounding environment which is ideal for all types of projects.
For industrial and transport applications it is best to use a solution that is suitable for exposed locations with high wind loading to meet stringent standards, including Highways Agency standards BS EN 1794-1 and 2 and the National Highway Sector Scheme 4.
With so much to consider, we recommend that contractors discuss requirements with an independent sound engineer who can provide a detailed report on the best solution. This ensures an informed decision can made on the most appropriate acoustic barrier that will be fit for purpose and limit unwanted noise.
Jacksons Fencing designs and manufactures the highest quality acoustic timber fencing solutions in the UK, with some products achieving noise reductions of 28dB and 32dB in certified laboratory tests.
Its new guide highlights the impact of sound and provides advice on how timber acoustic barriers can reduce unwanted noise and improve surroundings with natural facades that are sustainable and cost-effective.
Main image: Wei Huang/Dreamstime