Wood is naturally sound-damping, offering excellent noise control. As a result, wood has long been specified for applications requiring the amplification of sound (such as a concert hall) or its mitigation (such as a library). Acoustic design considers a number of factors, including building location and orientation, as well as the insulation or separation of noise-producing functions and building elements. Wood can contribute to insulating and separating areas of a project.
Sound Transmission Class (STC) and Impact Insulation Class (IIC) ratings are used to establish the acoustic performance of building products and systems. Designers can also establish STC ratings for the project and specify materials and systems to ensure the building performs at that level. This should be considered during the project’s design phase.
There are many sources of noise throughout the building and around the site, from the continual hum of the HVAC system to the chatter among building occupants to the intermittent whir of emergency vehicles and other traffic outside. Such noise can travel above or through the ceiling, deck and floor joists, windows and doors. Sound can also travel through fixtures and fittings, such as electrical outlets and recessed light fixtures. Perimeter joints and wall partitions are also vulnerable to sound transmission.
Green-building certifications such as LEED are beginning to incorporate acoustics more prominently. Designers seeking such certifications have historically overlooked wood in favor of hard, reflective surfaces that are easy to clean. However, many are beginning to reconsider wood for its advantageous acoustic performance.
In addition to also being easy to clean, wood surfaces offer advantages beyond acoustics, including the ability to be sourced locally and store carbon, strong thermal performance, low VOC emissions, and reliable behavior during fire and seismic events.
As an insulating material, wood has a role to play in ensuring building interiors can achieve efficient, desirable thermal performance. However, wood doesn’t act alone. A building’s shape and orientation, the volume and location of the thermal mass, the efficiency of enclosures such as windows and doors, and the degree of insulation used are all factors to consider when evaluating thermal performance.
However, as thermal efficiency requirements for building enclosures increase, wood is a natural solution to pair with other insulating and weatherizing materials to ensure consistent thermal comfort indoors. Unlike concrete and steel, wood does not need a thermal break between the structural and exterior envelope. Additionally, wood sheathing products such as plywood can be an asset to designers looking to implement continuous, solid exterior barriers to prevent air leakage, which is now required by building codes in some regions.
Prefabricated mass timber components such as glue-laminated timber (glulam) beams—as well as cross-laminated timber (CLT), dowel-laminated timber (DLT) and nail-laminated timber (NLT) wall, floor and roof panels—are finding use in projects across the U.S. Due to their thickness, these wood products deliver thermal insulation and thermal mass. For projects seeking to meet net-zero energy or other stringent energy performance criteria, wood can store solar heat energy during the day and release it at night, reducing energy loads.
Learn more about wood’s role in energy efficient buildings in this continuing education course.