-By Victoria Cerami

Clean air, natural light, thermal comfort, a productive ambience are all elements of indoor environmental quality that come to mind when we think of successful corporate interiors. They all contribute to occupant health and performance. Paradoxically, however, sustainable design often leaves acoustics out of the picture. Except in the case of LEED for Schools (with LEED Healthcare on the horizon), there are no LEED credits for acoustics. This oversight is compounded by the fact that designers can inadvertently compromise acoustics when designing green.

It is not that acoustics are deemed unimportant. Routinely, distracting noise and lack of acoustical privacy are at the top of workplace complaints. In green buildings, it turns out, it can be even worse. In a 2006 report by the Center for the Built Environment (CBE) at UC Berkeley, surveys showed that occupants of LEED-rated and/or green buildings were found to be more satisfied with their indoor environment than their counterparts in non-green buildings. Yet, when it came to acoustics specifically, occupant satisfaction was lower in green than in non-green buildings. (Click here to view CBE chart.)

Designers are eager to design sustainably, and sometimes their strategies—such as using fewer materials, avoiding synthetics, limiting toxic materials and finishes, as well as maximizing natural light—translate into open plan spaces with fewer walls, high and exposed ceilings, and hard surfaces all around. These design approaches can reduce the opportunity for sound absorption, creating inherently noisy spaces. Leigh Stringer of HOK and author of The Green Workplace says, "More often than any of us would like, green strategies present a challenge to acoustics." For Stringer, this is no small matter. In fact, she categorizes unwanted noise in the green workplace as a "productivity inhibitor."

Rectifying acoustical problems after a space is occupied can require more complicated or costly solutions than if those issues were avoided in the first place. So how can designers create sustainable spaces that also support occupants' acoustical needs? Scot Horst, senior vice president of LEED at the USGBC, feels that good sustainable design always requires an integrative design process. "Green design presents challenges to acoustics, but hopefully it encourages people to think more holistically about their projects so that they pull in an acoustic consultant early on," he says.

Designers also can focus on the specific spaces that require good acoustics. Today, the office environment typically needs to support a variety of activities, from teamwork to private concentration. Therefore, acoustical quality should vary according to a space's function.

The good news is that manufacturers continue to improve the green features of acoustical products such as ceiling tiles and resilient floor underlays. The roster of quality sustainable products in general also continues to expand, making the use of sound-absorbing materials not necessarily marketed as "acoustical products" (such as carpeting), much more attractive for the green designer. Current options for sustainable acoustical products include cotton duct lining, cork, slotted wood systems, recycled cotton wall panel cores, and cotton absorptive panels that can be used in place of fiberglass. However, these materials come at a premium cost.

Making LEED credits for acoustics available beyond LEED for Schools would stimulate development of more affordable products as well as help raise awareness among designers about its critical role in the indoor environment. Horst feels acoustics is a strong candidate for the USGBC's recently launched Pilot Credit Library program. This enables designers to recommend and provide feedback on credits (as innovation points) and facilitates their eventual official credit status in the broader LEED system.

David Lehrer, director of communications at the CBE, feels there is a lack of awareness of acoustics in the industry that LEED credits would help address. He compares acoustics' low profile to another USGBC oversight. "Until recently, energy was somewhat overlooked in LEED," says Lehrer. "You could have a very highly ranked LEED building that merely complied with the energy code."

One reason the USGBC does offer acoustics as a credit for LEED for Schools is that research demonstrates the correlation between sound quality and learning in the classroom. More research is needed to validate the impact of noise on occupant health, comfort, and performance in the workplace.

Acoustics credits for LEED, greater awareness, research, and more product options will help designers create green spaces offering quality acoustics. Until then, designers should know that it doesn't have to be a trade-off.

Victoria Cerami is the CEO of Cerami & Associates, Inc., a globalacoustical, audiovisual, and technology consulting firm.