Acoustic Façade Systems


Whether you want to improve your building's performance or reduce acoustic transfer through the glass component of your building then Thermosash secondary double glazing could provide the solution.

Thermosash secondary double glazing has been designed to combat the widest possible range of thermal and acoustic problems. Thermosash have installed over 5000 units in New Zealand since introducing them in 1973.

The specification of Acoustic rated facades are common where office buildings or Residential Apartment buildings are located in close proximity to noisy environments. Thermosash have been engineering façade systems that meet or exceed high performance acoustic conditions for many years.

Our most recognisable suite for this is our Stick System Curtainwall CW400 / CW600 / CW900 which is also thermally isolated, our Delta Commercial Suite (which is ideal for lowrise and highrise apartment buildings) and our twinwall engineered systems combined with almost any of our suites.

Our flush glazed PW1000 curtainwall suite was installed at the Auckland International Airport in the Novotel with a jockey sash incorporated into the design.

Paul Columbus, Novotel General Manager is quoted as saying;

"The façade soundproofing is so whisper quiet, I couldn't hear an Airbus A380 take off, only a few hundred metres away."

In 2002, Thermosash had our Delta Sliding door tested acoustically by Norman Disney Young, It was noted that our sliding door performance was very good, with results very close to a hinged door.

The report was summarised as follows;

"...this is certainly a very impressive result for a sliding door and one of the best we are aware of. Following the initial test, we have recommended this system for a number of projects where traffic noise has been of concern."

The full report is available upon request

For optimum acoustic performance of secondary double glazing use a glass which differs in thickness by at least 30%, (e.g. 4mm + 6mm + 10mm). Sound reduction will improve with increased glass thickness (particularly at higher frequencies) due to the greater mass involved.

Performance / Testing

  • AS/NZS1170 (Structural Design Actions)
  • NZS4223 (Glazing in Buildings)
  • NZS/AS4284:2008 (Water / Air Pressure/ Air Leakage - Meets and exceeds minimum requirements)

The standard warranty is 5 years from the date of practical completion for these products. This covers workmanship and weather tightness, providing the subcontract includes fabrication, installation and glazing of all components.

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System Features

Thermal Performance Benefits

The insulative efficiency of an IGU is largely determined by the thickness of the space between the two sheets of glass and whether this space is filled with air or a gas such as argon or krypton. Should the space between be too little, this provides a conductive heat loss between the panes whereas if it is too large, a convective current can begin to circulate causing heat transfer also. Generally, the gap is between 16-19mm. As the separation reduces heat gain or cooling from the transfer of cool surfaces - the technology also works in limiting heat loss from the internal environment.

As one of the largest single running costs of a commercial building is attributed to the conditioning of air (heating or cooling) commercial double glazing can provide significant energy savings to almost any project.

Acoustic Benefits

Increasing the width of cavity produces an increase in sound insulation but not pro rata. Beyond a spacing of about 200mm the incremental acoustic improvement is small and, generally, an expensive unit to install due to typical existing reveal depths. Sound reduction will increase with the use of laminated glass, due to the vibration dampening effect of the PVB or by lining the cavity with sound absorbent insulation material, generating sound reduction of 10db (50%) is generally quite achievable with this product, based on limitations of existing building in conditions.

Relevant Projects

Novotel Auckland Airport

Novotel Auckland Airport


Warren & Mahoney



Napier Street GHD

Napier Street GHD


Jensen Chambers Young

Mansons TCLM