Passive Design

Designing the building and the spaces within it to benefit from natural light, ventilation and even temperatures.

Noise control in the building envelope

Exterior building elements can be constructed to limit the effects of exterior noise.

On this page:

  • sound-attenuating external walls
  • sound-attenuating roofs
  • sound-attenuating external doors and windows

The two types of noise that the building envelope must be able to keep out are:

  • airborne sound passing through gaps and openings
  • structure-borne sound from impact or vibration.

Sound-attenuating walls, roofs, windows and doors can be used to block external sources of noise. They are frequently difficult and costly to retrofit into existing homes so they should be considered during the design stage of a new building.

Sound-attenuating external walls
Where external walls face a source of outdoor noise, they should be of heavy construction and without windows or doors if possible. If doors or windows are necessary, doors should be solid with seals around the opening, and windows should preferably be non-opening, using sound-attenuating laminated panes.

Acoustic performance of framed walls may also be improved by:

  • using staggered stud framed construction
  • incorporating proprietary sound absorbing materials into the ceiling construction
  • using a proprietary acoustic rated wall construction system.

Options for sound-attenuating wall construction

External sound envelope (fibre cement cladding) 
External sound envelope (fibre cement cladding)

A high-density sheet cladding with sealed joints, thermal insulation, and sound attenuating interior lining will provide sound reduction using lightweight construction.

External sound envelope (brick veneer) 
External sound envelope (brick veneer)

A brick or concrete masonry veneer with a rigid air barrier, thermal insulation and sound attenuating interior lining uses heavy weight construction to provide effective sound reduction.

External sound envelope (concrete masonry) 
External sound envelope (concrete masonry)

A high density sheet cladding installed over battens, interior strapping, thermal insulation and sound-attenuating interior lining will provide an effective sound barrier.

Sound-attenuating roofs
Sound-attenuating roofs are difficult to achieve. One option is a concrete slab roof but this would only be justified in extreme circumstances such as under the flight path of planes at low level.

Other options that include the ceiling construction as an integral part of the sound attenuation system:

  • Bitumen-impregnated underlay under long-run profiled metal roofing a low-cost option that will reduce rain noise, but most other noise will be transferred through the fixings.
  • Concrete or tiled roofing this will reduce the impact noise of rain and hail but airborne noise will be able to penetrate through the gaps in the roofing.
  • Long-run profiled metal roofing with plywood underlay, thermal insulation, a sound-attenuating ceiling without down-lights, no rooflights and the roof vented on the side away from the source of noise this will provide effective sound reduction
  • Incorporating proprietary sound absorbing materials into the ceiling construction.

Sound-attenuating external windows and doors

Windows

Windows in walls that must be sound-attenuating should preferably be non-opening, since air currents carry sound. Options for sound-attenuating windows:

  • Thicker glass means greater mass, and hence some sound reduction. This tends to work better with lower frequency sounds.
  • Standard laminated glass will provide significant sound reduction as long as the window is not opened. The resin layer between the two panes of glass dampens sound vibrations. Acoustic laminated glass has a centre layer that is softer and more elastic, designed specifically to reduce noise transmission.
  • Insulating glass units (IGUs) are an effective option as long as the window is not opened. Laminated glass can be used in IGUs. For optimal performance, specify double-glazed windows with a non-metal spacer between the sheets of glass they transmit less sound than windows using traditional metal spacers. Triple-glazed windows are very effective at reducing sound transmission, but more expensive than double-glazing.
  • Fitting additional glazing to the window reveal a very effective option although it may prevent the window being opened.

Sound-control glass will only perform properly if all air gaps around a window are properly sealed.

When windows are open, any sound rating is lost. In some situations, windows may only need to be closed for part of the day such as during rush hour or during school break times.

Where windows must remain closed to reduce noise, mechanical ventilation systems may be needed to replace the lost ventilation.

Doors

Sound-attenuating doors should:

  • be solid core doors
  • not have glazed panels, or be fitted with sound-stopping laminated glass
  • have brush, foam or rubber seals all round.

 

Updated: 17 September 2018