A Canadian guide defines best practice in sustainable, public financed office buildings. In section 2.9.1, named “Flanking and Isolation”, performance criteria and methods are addressed:
The integrity of acoustical partitioning can be maintained by:
* Extending partitions above the suspended ceiling;
* Eliminating holes for ducts, pipes, conduits, cables etc.;
* Providing appropriate acoustical treatment on doors, sidelights, etc.;
* Minimizing or eliminating break-in and break-out sound transmission through air ducts passing through the partition.
Other studies support the fact that lighweight walls going through the suspended ceiling, and thereby sectionning the plenum is necessary to achieve the “true isolation performance”, i.e. the site performance actually expected by the end-users of the office building.
In the above picture, meeting room adjacent to a cellular office, the result expecte by the user is confidential privacy. This can be translated into a site value (R’w) of at least 44-45 dB.
Guide de l’architecte pour la Conception d’immeubles de bureaux en fonction du développement durable