Green buildings are designed, constructed and operated for the purpose of providing the occupants with a space that is both healthy and productive, while also being energy efficient and sustainable. Unfortunately, current approaches to green building design and construction don’t always meet occupants’ indoor environmental quality (IEQ) needs for “acoustic comfort.”
Acoustic comfort refers to an indoor environment that is conducive to providing speech intelligibility, speech privacy, low distractions and annoyance, and sound quality.
And, according to ongoing research at the Center for the Built Environment (CBE), it is the lowest performing IEQ factor in green buildings. Moreover, in all buildings surveyed, the level of acoustic satisfaction was rated as the lowest performance IEQ factor, and the only negative (dissatisfaction) factor overall.
There is no need, however, to sacrifice good acoustics when selecting products for green buildings. Architects and interior designers do not have to choose between sustainability, design and acoustic needs—they can have all three.
Outlined below are a number of acoustic considerations for green buildings in three market segments: healthcare facilities, commercial offices and educational facilities.
Acoustics are a key element in the IEQ of healthcare facilities because they play an important role in supporting the safety, health and well-being of patients and staff alike.
In general, ambient noise levels in hospitals are high, and have been shown to be a source of annoyance and stress to both patients and staff. They can also interfere with the staff’s ability to work effectively. Because of this, both the FGI 2010 Guidelines and LEED for Healthcare address the issue.
One reason healthcare facilities are so noisy is the predominance of hard, sound-reflecting surfaces that cause speech and activity sounds to persist much too long. When acoustic conditions are characterized by long reverberation, spoken words are perceived to overlap, resulting in reduced speech intelligibility.
To reduce reverberation and noise levels, acoustical ceiling panels should have a noise reduction coefficient (NRC) of 0.70 or greater. (The NRC indicates the average percentage of sound a material absorbs; an NRC of 0.70 means the material absorbs about 70 percent of the sound that strikes it.) They should also meet healthcare standards for washability, mold and microbial resistance, and fire safety. Ceiling panels with these characteristics are ideal for patient rooms, treatment rooms and other spaces that require a balance of cleanliness and quiet.
Ceiling panels with a NRC of 0.95 are recommended for areas that require even higher levels of sound absorption to ensure patient privacy and meet HIPAA regulations. These include open plan spaces such as waiting areas, pharmacies, nurses’ stations and closed plan spaces where walls extend up to the deck above.