5.11 Acoustics of Open Plan Offices

Privacy indicates the level of acoustic separation between desks in an open plan offi ce. If privacy levels are too low, speech, phone calls and other noise sources can cause a noise nuisance to multiple office users. Privacy between work stations is the main acoustic consideration in the design of open plan offices.

Privacy is both a function of background noise and the prorogation of sound between work stations. As such it is important to consider the design of environmental noise break in or services noise; both these parameters should not be designed too low. Background noise levels within a naturally ventilated building are hard to keep constant due to variations in road traffic levels, the potentially quiet location of the building and other factors. The use of acoustic screen and other factors within the office space therefore become more critical in these buildings.

BREEAM background noise requirements are a function of office size; large open plan offices have a higher noise requirement. Additionally, an upper and low level is provided by BREEAM such to guarantee a degree of noise masking in large offices.

In MACH Acoustics experience offices can be designed with little or no acoustic absorption whilst still providing a suitable acoustic environment. The key is to ensure that line of sight between desks is obstructed by screens, the layout of the building or other elements. It is also important to prevent reflections from hard surface/soffits. This can be done by placing panels of acoustics absorption over desks in combination with a coffered ceiling or down-stand beams.