Standards for acoustics in schools
Children are among our most vulnerable populations because their auditory development and cognition have not fully developed; as such, the need for a good acoustic environment in schools is increasingly well understood.
Noise can contribute to distraction, lower academic performance, and stress (new research is also suggesting that the noise generated from bathroom hand dryers, often found in schools, is harmful to children). Accordingly, guidelines have been developed to address the specific acoustical needs of educational settings.
ANSI standards for classroom acoustics
The main standard that addresses this is ANSI/ASA S12.60 with information about acoustical performance criteria, design requirements, and guidelines for schools. There are two parts of interest, Part 1: Permanent schools, and Part 2: Relocatable Classroom Factors (applicable for portables).
S12.60 includes a provision stating that “for high-noise sites (peak-hour Leq above 60 dBA during school hours), implement acoustic treatment and other measures to minimize noise intrusion from exterior sources and control sound transmissions between classrooms and other core learning spaces; projects at least one-half mile (800 meters) from any significant noise source (i.e. highways, trains, and aircraft overflights) are exempt.”
Collaboration for High-Performance Schools (CHPS) and LEED for Schools (see below re: LEED v4) have sections on acoustics based on and in reference to ANSI/ASA S12.60. The overall goal of these voluntary programs is to support healthy learning environments for students and teachers. As it relates to acoustics, these guidelines aim to reduce distraction from noise, reduce strain on teachers and improve collaborative communication in the classroom.
Supporting and advancing health and wellness of building occupants
The WELL Building Standard™ was developed by The International WELL Building Institute™ (IWBI™) as a standard for building construction with a focus on supporting and advancing human health and wellness. It recognizes the potential impact that built environments can have on occupants. One of the seven concepts that make up the WELL Building Standard is “comfort”. In WELL v2 there is a new ‘sound concept’ which aims to improve occupant health and wellbeing in the built environment through acoustical comfort.
The primary objective here is to reduce the most common sources of distraction and irritation for occupants, as well as to enhance those elements that create a positive experience. Acoustics pre-requisites and optimizations are included in this section “to shape spaces, to mitigate unwanted indoor noise levels, and to reduce exterior noise intrusion in order to enhance social interaction, learning, satisfaction, and productivity.” Specific features of the guidelines take into account reverberation time, sound masking and incorporating sound-reducing surfaces.
Standards for “green” construction have the potential to negatively impact acoustics
Any discussion around sustainable construction practices almost always includes LEED v4. It is the most widely recognized and adopted building rating system globally. In Canada, LEED v4 is administered by the Canada Green Building Council (CGBC); in the United States, by the US Green Building Council. Both parts of LEED that are applicable to schools and healthcare facilities which were discussed above have been incorporated in LEED v4.
Though many environmentally conscious professionals in the industry have moved to adopt the rigorous standards of LEED v4, the implementation of many of its initiatives can at times, unintentionally, degrade acoustical performance. Common complaints around acoustics in “green” buildings include uncontrolled noise and lack of privacy. These issues can occur with the presence of hard, reflective surfaces (e.g. glass, concrete, exposed metal) that don’t absorb sound. In addition, the sound isolation capabilities of walls, roofs, windows, and partitions should be carefully considered during the acoustic design and engineering phases of any project.
Further to the above, the LEED v4 standard for the design of high-performance green buildings lists the following outdoor-indoor transmission class (OITC) and sound transmission class (STC) requirements:
- OITC and STC requirements where buildings are within five miles of an airport serving 10,000 jets per year,
- The yearly day-night average sound level (DNL) at the property line exceeds 65dB, or
- Buildings are within 1,000 ft from a highway/expressway.