Closing the Window on External Noise: New Solutions Required
Pressure by planners to impose onerous standards for external noise intrusion for new residential units in noisy locations is leading design teams to specify non-openable windows. "The truth is," reveals Tony Holdich, "that an openable window has an upper laboratory rated performance in the region Rw 45 dB (with spectral performance that may not suit many schemes); however, if you remove the operating mechanisms and use fixed elements, usefully higher levels of noise mitigation become available and you get a lower build cost." Whilst the matter of ventilation sufficiency is resolved by the use of appropriately specifiedwhole-house ventilation units, manufacturers, according to Tony, are lagging in making available suitably rated atmospheric duct terminations. "We are seeing conditional planning consent for residential schemes at locations that government guidelines recommend refusal on the grounds of noise alone," points out Tony. "So, it's up to design team members to be open to new solutions as the essentially old problems of a little bit of noise ingress are turning into challenges of considerable proportion. Now, more than at any time in the past, acoustic design is likely to affect the very core of many scheme designs."