One company with a strong focus on noise control in construction through research and technological innovation is Arup. Those sobering numbers on death and ill health are reported in the opening paragraph of its Noise and annoyance report about construction noise and its impact on people’s health. “Unwanted sounds from infrastructure, transport and building projects can … provoke stress, poor sleep, and health problems,” it states.
In the UK, government guidance does not identify specific limits for noise levels. “Instead, it encourages developers to control and reduce noise above a determined Significant Observed Adverse Effect Level (SOAEL) – above which negative health consequences are likely,” says the report.
Noise pollution is something the construction industry has been researching and developing new ways of trying to combat, through invention, technological advances, and face-to-face meetings with those that will be affected. But what defines ‘noise pollution’? One of the authors of the Arup report, Adam Thomas, senior consultant, acoustics, says it is termed as “unwanted sound, although there is a subjective element to noise itself. However, noise from construction sites, is probably going to be classified as noise to most people – an unwanted element in their lives.”
Arup’s research with the University of Salford in Manchester, outlined in the report, moves away from a blanket approach of noise assessment to investigating, what it calls ‘soundscape’, a term used to describe human perception of sound. It found a correlation between self-reported annoyance and an increased heart rate, that younger people appear more sensitive to noise, and that changes in skin conductivity occur with different soundscapes.
The WHO report Frontiers 2022: Noise, Blazes and Mismatches, on noise pollution around the world, highlighted the noise levels found in a selection of cities around the world. The data is based on traffic-related noise during the daytime.
The results show Asia has particularly bad problems with high noise levels in cities. This matches the findings of the World Hearing Index Report by Mimi Hearing Technologies, which found India and Pakistan are among the countries with the most people with hearing difficulties.
Under official legislation, British firms are controlled by two separate regulations – the Control of Pollution Act 1974, and the Environment Protection Act, 1990 – that set out, in principle, how companies should work. Planning authorities take a ‘community’ approach to sound, with acceptable noise levels established based on their impact on the entire community.
David Owen, associate director at Arup, says there is a requirement under the Control of Pollution Act to minimise noise and vibration by demonstrating best practical means. “Anybody making noise on a construction site, if they want to avoid nuisance claims or anything of that nature, they must always be minimising it as far as reasonably practical. This should start even before a company is on site,” says Owen.
He adds: “When you’re working on site, you ask what controls do you have, what are the processes, how do you do your piling, and what kind of methods do you use? Can you demolish using non-percussive methods? Can you cut sections of the building apart, then put it on to vehicles, take it off site, and demolish it elsewhere? These need to be considered, and form part of that best practical means justification.”
Steps taken by companies to reduce noise include using acoustic barriers, encasing entire developments, using prefabricated constructions, even plants and greenery, or simply engaging in conversations with those affected by the works.
When the central London-based Rothschild Bank, was being constructed in its fourth iteration (completed in 2011), it had an acoustic barrier thrown around it using a scaffolding system called Layher, with a cladding system called Protect.
It works by using a lightweight aluminium frame in-filled with sheet steel or plastic webbing to create a complete ‘skin’ around a structure. The Layher website adds that “both internal and external protection is achieved, and additionally, sound absorbent matting can be fitted to minimise noise pollution.”
At one site where work is being carried out, Chambers Wharf in Bermondsey, a warehouse-type unit has been built over the entire construction site to minimise noise to residents. Plants, particularly ivy, were also grown on hoarding on one end, to minimise the impact of noise. “These are all things’ people are doing on site to try and improve these situations,” says Owen.
That also includes the increased use of prefabrication. “There is a lot more happening off-site,” says Owen. “Units are built somewhere, in a factory, put on a lorry, brought in large sections and the final assembly is done on site.” This means most of the construction noise is happening elsewhere.
But sometimes, it is the simple things that work, like communicating with those the noise affects. “It’s been shown time and again if you meet with someone, and explain what’s going on, tell them about the noise that will happen, then they are more reassured and they understand the process,” says Thomas.
The annual Chartered Institute of Environmental Health (CIEH) Noise Survey showed that in 2020, the first year of lockdown, noise complaints rose by 54% in England. It says: “The results suggest that the increase in people staying at home at the height of the pandemic contributed significantly to the 356,367 noise complaints recorded by 144 local authorities (45% of the total). This equates to an average of 149 complaints for every 10,000 people.”
“People have become accustomed to the quieter periods of lockdown,” says Ric Hampton, divisional director for acoustics and air quality at engineering consultancy Hydrock. “There are going to be more changes in the future as we move to electric vehicles that will redefine the background sound levels of urban environments. The lower the background sound, the more annoying other noise becomes.
It is also worth thinking beyond engineering solutions and considering human behaviour, says Hampton. “Noise pollution is the second-largest environmental cause of health problems according to the World Health Organisation (WHO) and human beings are conditioned to respond to loud noises by releasing cortisol, the stress hormone.
“If we consider these factors as well, we can take a more holistic approach to the management of noise.”
And with construction companies around the world continually improving their noise control, whether that be through new technology, different ways of working or doing more of the noisy work off-site, the hope will be for a quieter, healthier future.
Given some drones can weigh up to 15kg with eight rotors, there are noise pollution issues for residents, offices workers, or even schoolchildren near sites. To investigate the impact of drone noise, Arup is working with an academic partner, the University of Salford, on research which started in 2019 and will run until May 2024.
“We are focused on addressing how you measure, model, and understand that noise from an acoustic perspective,” says Dr Antonio Torija Martinez, lecturer at the University of Salford in acoustic engineering.
“We are also trying to understand the noise perception of drones, the effect drones might have on communities and how we might be able to minimise that impact.”
In the case of the larger drones, Martinez says increasing the number of rotors creates issues. “You tend to have more tonal, and rough sound, which is more disturbing. While you have these operating in the proximity of buildings, it’s quite likely a substantial amount of noise is going to be transmitted to the inside of the properties, which might affect the people living there.”
Regulations are not yet in place for the use of drones; however, licences are granted based on payload and the size of the drone. Because of this, Hampton says: “We’re seeing smaller drones being developed to get around the use of specific licenses and just adhere to the general restrictions.”