What Must Be Fixed Now vs. What Can Be Fixed Later

Because acoustics are difficult to predict and calculate, many designers feel it may be easier to simply make a best guess, then deal with the issue post-occupancy if it turns out to be a problem. In some cases, this may be a reasonable approach. For instance, mid-range restaurants that have at least a minimal acoustic treatment may prefer to wait until the opening to determine if investing an additional $5,000-$15,000 makes sense to make the sound clearer in the space (unlike soundproofing, it’s possible to “overtreat” a room with acoustic treatment, making it sound like a “dead space”).

However, when it comes to soundproofing, the cost to retrofit partitions and floors to an acceptable level, the cost is prohibitive. It generally requires taking all drywall off of the studs and starting the partitions from scratch, sometimes adding a second set of studs if the first set were not sufficiently spaced or flexible. Adding STC or IIC to a respective wall or floor-assembly can cost 20x as much when doing it a second time, rather than correctly addressing it initially.

*Whenever possible, a field test should be conducted of the initial unit to ensure that the IIC and STC are acceptable. Even a functional test (read: real world simulation) of listening in one room while a partner walks with boots or heels, stomps around, and blasts music and TV in an adjacent space, can provide some insight.

Cost of Acoustic Solutions

The cost of certain acoustic solutions increases dramatically if added near the end of construction or certificate of occupancy. For instance:

• Acoustic Treatment cost only increases slightly. Panels, clouds, fabric walls and other absorption options are surface mounted, and can be installed into an existing space. The only cost increases will include added labor for working around finished and occupied areas.
• Sound Masking, likewise, can be installed after tenant turnover. It is ideally installed after the ceiling grid but prior to acoustic ceiling tiles. Added labor accounts for moving and replacing tiles, as well as running cable in plenums that are more difficult access after construction is complete. Also, overnight installations are common so as not to interrupt commercial operations during the day.
• Soundproofing costs increase prohibitively once wall framing and drywall hanging is complete. Adding STC or IIC to completed wall and floor-ceiling assemblies cannot be done in a cost-effective manner. Increasing the soundproofing performance of these assemblies often requires complete demolition back to the studs, or if the studs were improperly framed, to the building envelope.
  • NOTE: There is no magical soundproofing wall paper or paint that may be used to increase the STC of existing walls.

Therefore, when performing design trade-offs, consider that the risk profile of some design decisions is much greater than others. While acoustic comfort and speech privacy should be considered during detailed design, the mitigation options after occupancy “only” increase by 30-50%. However, the cost to improve the STC to an under-designed wall often increases by 2,000% or more, and requires complete demolition of the space.