Acoustic specification

UK city centre housing stock has increased by 16 per cent since 2011, nearly three times more than the increase in the suburban housing stock, making acoustic insulation key to development. Paul Stevens, Managing Director, Acorn Aluminium discusses.

The planning system is pushing development to brownfield city centre sites. It’s a key part of the Government’s Levelling Up strategy and it maximises the use of pre-existing space.

Brownfield developments, however, come with specific challenges – including noise – something, which has a proven link to ill health.

A recent study by the World Health Organisation (WHO), found that long-term exposure to environmental noise is estimated to cause more than 48,000 new cases of ischaemic heart conditions and 12,000 premature deaths each year in Europe alone.

6.5million Europeans suffer chronic sleep disturbance, with 22 million people suffering long-term chronic annoyance.

Designing out noise through acoustic glass

Some form of acoustic glazing is now almost standard in the urban residential specifications that we see.

It limits noise pollution through the deflection and dissipation of soundwaves. It does this through a combination of glass thickness, the use of acoustic interlayers and the space between the glass.

The focus here is on the linear direction of travel – how sound is transferred between inside and outside spaces and vice versa. 

Managing the vertical transfer of sound in curtain walling 

The right acoustic insulation is also critical in preventing the transfer of sound vertically in curtain walling. Curtain walling transcends floors and as its hollow, conducts sound, which makes the correct acoustic insulation a critical element of specification.

It’s something which acousticians work with a lot and there are some very effective solutions available. In curtain walling mullions, these generally rely on system specific acoustic baffles, which are extruded to fit exactly to a specific curtain walling system.

This significantly lowers the transfer of sound between floors, something which left unchecked can clearly have a significant impact on residential developments, particularly those in noisy city centre locations.

Case study example: Coventry Hotel Indigo

The Indigo Hotel in centre of Coventry is a good illustrative example.

Designed by architects Chapman Taylor, Coventry Hotel Indigo is a 100 room, 5-storey, 4-Star hotel including a 100-cover fine dining restaurant, gym, bar and guest lounge at ground level.

Curtain walling forms a key element of the design and is used extensively at ground-level to create a sense of openness and light. It’s also used by the architect to define the overall appearance of the building, with darker ‘columns’ of recessed curtain walling, contrasting with silver-blue metallic cladding.

We were appointed to supply 815m2 of SF52 Curtain Walling from Senior Architectural Systems to the scheme, SPW600 windows and SPW501 doors, plus automatic entrance doors.

The site is situated within a stones’ throw of Coventry Railway Station. Making up a key element of the City’s Station Square and the Friar Gate development and surrounded on all sides by high rise office buildings and bustling roads, plus pedestrianised spaces, making noise insulation a key element of the specification.

In addition to an advanced level of thermal performance and solar control, the glass specification included a high level of acoustic control with a 42RW+CTR rating, significantly reducing traffic noise.

We carried this focus on acoustic insulation through to manufacture of curtain walling, using the Siderise V baffle, as an acoustic treatment for vertical sound transmission between floors.

Extruded specifically for the SF52 Curtain Walling System, this was applied by us in a factory environment and fully sealed before shipping to site, to guarantee maximum performance.

Concluding thoughts

There have been big regulatory changes already as the impact of nuisance noise on health but becomes better understood.

Increased focus on brownfield development in central high noise locations makes some sort of requirement for acoustic control increasingly likely on almost all projects.

The nature of sound, the fact that it is variable, and that nuisance noise changes at different times of the day in terms of both volume and source, means solutions will always need to be bespoke, balancing cost and impact.

We and our partners have extensive expertise in supporting contractors in developing specifications which deliver acoustic insulation where it’s needed without inflating project costs.

For more about Acorn Aluminium please call 0115 928 2166, email or visit

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