Determine if the calculation or measurement method is best suited for your project. 

Design all wall, floor, ceiling and composite assemblies to meet the required STC rating. See the STC Introduction in the Documentation Toolkit for more detail on determining the STC rating of various partition types.

Windows must have an STC rating of at least 35. Double-pane windows with a half-inch or greater air gap and laminated glass are usually best. The STC rating of windows is usually available from larger manufacturers. 

Research windows with an STC rating of 35 or greater. See the STC Introduction in the Documentation Toolkit for more detail on determining the STC rating of windows. 

The STC rating for each partition in a given classroom will vary depending on the adjacent space. For example, a classroom wall that is adjacent to an exterior space will need to have an STC rating of 50, a wall that is adjacent to a public restroom will need an STC rating of 53, a wall that is adjacent to the hallway will need an STC rating of 45, and a wall adjacent to a music classroom will need an STC rating of 60. 

The LEED reference guide gives a quick summary of STC requirements (shown here), but it’s worth referring to the ANSI standard, which gives you more information on determining the required STC ratings and provides design guidance on how to meet these requirements for each space type, most notably composite assemblies (such as wall with windows and doors). Note that the STC rating for adjacency to exterior spaces provided in the table is the typical minimum requirement and the appropriate STC rating will need further research on a case-by-case basis.

Determine the required STC rating for all wall, floor, ceiling, and composite assemblies (a wall with doors and windows) in classrooms and core learning spaces. The required STC rating will be dependent upon the adjacent spaces to each partition in the space (wall, ceiling, etc.). Use ANSI S12.60-2002 to determine these ratings.  

Sound Transmission Class

Including a microphone and speakers or other electronic amplifiers in a classroom design will not contribute to credit compliance. Amplification allows the teacher to be heard more easily but does not reduce background noise. 

Meeting the STC and HVAC background noise level requirements can be documentation-intensive. If an acoustics consultant is doing the documentation, then they will be experienced enough to make this relatively easy. If it is a mechanical engineer who is not used to working with noise measurements, the terminology and procedures may take some time to get used to.