Healthy homes: designing out excessive noise
How many of us have learned the hard way that noise really does matter – and that a home with excessive noise levels very rapidly pushes stress levels to breaking point? One friend of mine was so disturbed by noise from people moving around the flat above hers that she slept in her bathroom for months. Her flat was in a converted Victorian house featuring wooden floorboards, so it’s no wonder noise was a problem. But timber, and the noise it produces, isn’t just an issue for historic properties – it poses acoustic challenges for designers of new-build residential developments as well.
The acoustics of timber floors is a complex issue for those designing residential developments, according to Philip Wright, from Arup’s acoustics team, who discusses the issue in a technical paper for UKGBC’s ‘Healthy Homes’ initiative. Timber floors really can “produce a ‘thudding’ sound”, acknowledges Wright, adding that the “testing and rating system normally used in the UK is limited in terms of how well it represents the subjective performance of timber floors”. Wright recommends the use of physical mock-ups to establish genuinely-acceptable timber floor designs.
Experiencing a building’s ‘noise climate’ in advance of construction
For other sources of internal and external noise, computer modelling is highly effective. In the case of Victoria Hall, a new student accommodation development in London’s buzzing King’s Cross area, an acoustic assessment by Arup’s acoustics team allowed architects Stanton Williams to understand the impact of noise from nearby trains. With noise forecast to reach up to 82 dBLAFmax on one side of the building, it was clear that substantial sound-insulating glazing would be essential and that open-able windows would not be advisable. More positively, the building’s ninth floor garden offered opportunities to design-in acoustic screening, and Arup’s team used software to quantify the screening contribution this would offer each of the building’s facades.
Rather than risk proceeding to construction with a design that could have resulted in excessive noise in some parts of the building, the project team used Arup’s Soundlab™ to fully experience the building’s contrasting ‘noise climates’. The results of this auralisation test allowed final decisions to be made that further protected the north side of the building from train noise, including the introduction of acoustically-lined trickle vents.
The distress and health impacts of living in an excessively-noisy environment are increasingly quantifiable, and in 2014 the respected medical journal The Lancet published an influential overview of research in this field. Needless to say, my friend who spent months sleeping in her bathroom is happy to personally – and vehemently – endorse these research findings.
For an overview of acoustics issues in new residential design, please see Philip Wright’s technical paper, Healthy Homes: Acoustics.