- By Amy Milshtein
- May 1st, 2010
Architects and designers know materials. They understand traffic patterns, weight-bearing walls, and visually arresting finishes. Acoustics may not be on the top of their must-consider list when creating signature gathering spaces like cafeterias or student unions, but they should be. These areas pose specific acoustical challenges, and dealing with them early in the design phase can make the difference between a comfortable space and a costly fix.
“Most of our clients are not thinking about acoustics unless they’ve experienced a problem in the past,” said Steve Thorburn, principal consultant, Thorburn Associates. “Often owners blame the architect for the problem, but that’s not fair for a couple of reasons. Design professionals don’t receive a lot of training in this area. Instead, they are thinking aesthetics and cleanability. Unfortunately, the materials that easily meet those criteria are hard and make for a loud space.”
If It’s Loud, It Will Get Louder
Other factors add to the mix. The popularity of food-court-style multiple serveries means more noise-making cooking equipment like grills, fryers, and venting hoods in the eating areas. HVAC systems are naturally loud, and a minimalist design approach with exposed ductwork and roof deck amplifies that effect. Glass walls add light and views, but they also give sound a perfect surface to bounce off. And then there is the “cocktail party effect.” “That’s when people have to progressively talk louder and louder over each other to be heard,” explained Kenric Van Wyk, president, Acoustics by Design, Inc. “It really adds to the noise level.”
Eventually the noise will reach a tipping point and your signature gathering space becomes an empty hall. “An enjoyable interior is like a three-legged stool,” said Jim Holtrop, principal acoustical consultant, Acousticontrol. “You need light, temperature control, and acoustical balance — otherwise, it just doesn’t work.”
The time to achieve this balance is, of course, in the design phase. “That’s when collaboration brings the best, lowest-cost solutions,” said Holtrop. “Simple moves can control acoustics without affecting the design.”
For example, material choices have come a long way since the ugly, predictable options of old. “We stay away from the ‘developer’s special acoustical ceiling tiles,’” said Thorburn. Van Wyk agrees. “Today we have ceiling tiles with interesting finishes that sit in hidden grids,” he said. “There are also linear wood products that look sharp, and acoustical plaster that resembles painted drywall.”
“We use sophisticated 3D modeling to predict acoustics,” explained Van Wyk. “Then any concerns can be addressed before they become problems.” Sometimes the solution could be as simple as changing the hole size in a perforated surface or padding the back of a surface with acoustical insulation. Elevation changes can also dampen sounds.
Often the HVAC system presents a challenge. “In that case some insulation might solve the problem,” said Holtrop.
The end use should also come into play when considering acoustics. “Some areas are expected to be lively and louder,” said Van Wyk. “Large lobbies in student unions and cafeterias are crossroads and should buzz with sound and activity.” Design cues in these areas — like tall ceilings and expanses of glass — mark these areas as loud public spaces, and the acoustics should oblige. Intimate nooks and niches usually fan out from these lobbies, and care must be taken to keep the sound from spilling into them. “Soft seating and lower ceilings help take care of that,” continued Van Wyk.
Dining and Special-Use Areas
Dining areas can be divided into two camps. “One side says that dining should be loud and lively, like a café,” said Van Wyk, “while the other says it should be a place of respite to quietly eat, interact, and reflect.” Either effect can be achieved; even both options in the same general space, but goals must be laid out in programming.
Special-use areas also demand extra attention. “There are a few ways to control noise in a game room,” shared Thorburn. “Alcoves, niches, and soft ceilings and walls dampen things. You can also limit the volume on the machines themselves.” Movie theaters, bowling alleys, and large ballrooms also need consideration. “Standard drywall here is not going to cut it,” said Holtrop.
The worst time to attack an acoustical problem is after the fact. “That’s when it gets costly,” said Van Wyk. “Usually these buildings operate 24/7, so just shutting them down is an issue.” Still, there are solutions and fixes to be had. “Absorption has to be added to the space,” said Holtrop. “Acoustical banners or clouds, material sprayed on the ceilings and walls, hanging baffles, or a layer of insulation may solve the problem.”
Some resolutions cost more than others. “Hanging baffles can run as low as $2 a square foot,” continued Holtrop. “Window treatments, however, can go to $20 a square foot. But in a historic space that may be the only option.”
Acoustics are also important for projects that want to go green. LEED points can be earned by achieving higher levels of acoustical performance. “That’s just another reason to think about acoustics ahead of time,” said Van Wyk.