Focus on Acoustics: Acoustically Integrated Architecture in the LEED Era, Part I

The concept of Acoustically Integrated aRchitecture (AIR – a term coined by Thorburn Associates) is basic enough: AIR is a best practice in which the interface of disciplines (architecture, acoustics, AV engineering, lighting, interior design, etc.) creates spaces that foster human community (offices, campuses, institutions, theaters, retail, worship, etc.) When the building in question is a LEED structure, the physical conditions are different and a synergy of strategies is called for to achieve the ideal, integrated result.

To earn LEED credits for indoor air quality and reduce energy use, many building designs opt for natural ventilation. It’s essential to go into such a project with a realistic assessment of noise levels around the building, because when you open up the shell, you opt out of complete control over the acoustical environment. Open windows, doors and/or skylights let in outside noise as well as air, which can adversely affect people’s ability to conduct business and interact.

On the other hand, too little background noise creates issues of speech privacy, particularly in open-office plans. A relevant example is the San Francisco Federal Building. It relies on the thermal mass of the building and natural ventilation for its heating and cooling. The windows can open at night and close during the day. The system is effective, but without the traditional background noise of HVAC systems, a conversation can be overheard in the open-plan office areas. One of several design services Thorburn Associates provided here was a sound masking system by which audio speakers (incorporated into the indirect lights in this case) introduce an appropriate level of background noise.

Another issue that arises frequently in open offices is sound reflectivity. Depending on the shape of the ceiling, sound may bounce around a room and call for acoustical surface treatment, something that is most cost-effective when planned in conjunction with the architecture.

Part II will look at audiovisual technology in the LEED environment and appear in another post.

Click here for Part II