Designing green buildings sounds like a great idea. But the reality is that energy-efficient buildings often sound downright crummy to the people inside them.
Surveys of occupants generally find that buildings meeting the Leadership in Energy and Environmental Design (LEED) standards, the benchmarks for greenness, score higher on all measures except one: acoustics. “It’s not a happy story,” Kevin Powell, research director for the U.S. General Services Administration, told the audience on the opening day of the meeting of the Acoustical Society of America in Portland, Oregon.
The GSA houses more than one million government workers in about 8,500 buildings across the nation. In post-occupancy surveys, acoustics often received poor marks. And while federal LEED-rated buildings scored a bit better than non-LEED buildings, on a separate survey commercial LEED-rated buildings scored worse than non-LEED buildings when it comes to noise, he said.
Some design elements that score well on LEED checklists, such as bare concrete ceilings that improve heating and cooling efficiency or low cubicle walls that reduce lighting needs, also allow sound to travel farther. A paradoxical problem: High-efficiency heating and cooling systems in LEED-rated buildings tend to be much quieter than wasteful ones, lowering inoffensive background noise that can mask distracting sounds.
Until recently, advocates of green building have neglected acoustical criteria. The ASA meeting marks the first time acoustical scientists and engineers have put the problems of green building design on its program. “There’s a need for the profession to understand what’s going on in the LEED world and a need for the LEED world to understand what’s going on in acoustics,” said session co-chair David Sykes, a consultant with Remington Advisors in Cambridge, Massachusetts.
Acoustical measures are becoming part of LEED-standards and building codes for hospitals and schools, but noise is often an afterthought for less specialized structures. Powell made a plea to the acoustical experts. “We need you to help us with best practices and enforceable standards that are achievable,” he said, because only when there is a clear and simple check box for acoustics will the indoor environment of green buildings ring true.
That might be tough to pull off because much of sound perception is subjective. As Powell pointed out, “There is no agreed-upon consensus of what good acoustics are.”
Top image: At the US General Services Administration, Auburn, WA, low, moveable partitions made of hard materials allow daylight – and voices – to diffuse across space. Bottom image: At the US Coast Guard, Oakland, CA, layout provides opportunities for collaboration; partitions provide some acoustical screening. Both courtesy Kevin Powell, USGSA