As noise pollution in urban areas becomes increasingly critical to public health, Phil Brown outlines the case for using measured data as standard for acoustic glazing

Phil Brown Pilkington UK headshot

Phil Brown, technical advisory service manager at Pilkington UK

According to the UK Health Security Agency, noise pollution in the UK results in the loss of 130,000 healthy years of life annually, with 40% of Britons exposed to harmful levels of road traffic noise.

Noise control glass for windows and facades is often the first line of defence in the fight for peace and quiet, shielding residents and workers from the buzz of urbanisation, construction and traffic.

However, using calculated data when specifying noise control glazing may lead to the selection of underperforming products for projects that demand more robust acoustic protection.

As our towns and cities grow louder, is it time for the building design industry to use more robust, measured data for noise control specification?

When it comes to fire safety, it is well-established that manufacturers’ claims must be supported by relevant test evidence. The Grenfell tragedy has reinforced the need for this ‘tried and tested’ approach over using assessments and judgement. As it becomes an increasingly important consideration of building design, the same stringent practice may need to be extended to noise control.

As is common for fire resistance, architects and specifiers should request test reports providing sound insulation data independently measured by a notified or approved body. This approach will help instil confidence that buildings can perform as designed, avoiding costly and challenging post-construction rectifications.

Higher levels of sound insulation are important, not only for providing a comfortable environment, but also for safeguarding health. The World Health Organisation links noise pollution to tinnitus, sleep disturbance, heart disease and other conditions.

But despite its importance, acoustic performance often lacks the same level of scrutiny applied to other safety critical products.

Knightsbridge Gate

Source: Pilkington UK

Pilkington’s laminated glass was specified for the refurbishment of Knightsbridge Gate multi-use development, used on the upper five floors to provide noise reduction for the busy, street-facing London landmark

We’ve measured the acoustic performance of our products for over 30 years, conducting our laboratory measurements in accordance with Parts 1 and 2 of EN ISO 10140, the test standard for sound insulation of building elements. Measurements are performed independently by a formally recognised notified or approved body, which is required for CE Marking and UK CA Marking.

In the absence of measured data, manufacturers can refer to generally accepted values of weighted sound reduction, Rw, and the adaptation terms, C and Ctr, for single, double and triple glazing configurations given in EN 12758. Although not permitted for CE Marking declarations, calculated or estimated sound insulation values are sometimes accepted on a project-by-project basis.

However, relying entirely on calculated data can be problematic. Some software may apply interpolation or extrapolation, often lacking third-party validation, which could lead to optimistic results.

Despite these limitations, calculators play a role in filling gaps where test evidence is unavailable. Fortunately, the European Standards body CEN has developed EN 17839, a standard for validating acoustic calculation tools for glass in buildings.

Published in 2023, the standard provides a methodology for assessing calculation tools, allowing producers to have their calculation tools formally validated by a notified body. Where specifiers are willing to accept calculated figures, they should at least confirm that the program from which the data originates has been validated in accordance with EN 17839.

The demand for high-performance acoustic products is increasing with more stringent project requirements. For such a critical decision impacting the building’s design, measured test evidence for acoustic performance can help architects and specifiers deliver trusted, reliable performance — much like they do for fire safety. By requesting and relying on independently measured sound insulation data, they can ensure that buildings perform as intended, providing both comfort and health benefits to occupants.