Our project is a high school and is the third school built from a prototype design. In the previously built school reverb time was measured and it met the requirements of EQ Prerequisite 3. Can we use these results from an identical school as submittal documentation for our project? Additionally, neither the reference guide or the ANSI S12.60-2002 specify the sampling criteria for reverb time. Is it acceptable to apply the same sampling strategy as is defined for STC rating? The ANSI S12.60-2002 specifies that we sample only rooms that are different in size and design so that is we have 15 identical classrooms we only need to sample 1 classroom. Additionally we want to confirm that according to the PIEACP issued in April, that if we review and analyze the local area zoning and long-range land use plans and determine that we are in a very low noise area (the school is on a remote site)and that other noise impacting uses are not planned in the vicinity of the site, that our windows do not need to meet the minimum STC rating of 35.
The applicant has posed three separate questions. The first question asks if a school based on a prototype design can use the reverb time measurements from previously identically built schools to demonstrate prerequisite compliance. Yes, if the project team provides a narrative confirming that the dimensions, finishes, layout, etc. are identical. The second question is regarding the sampling criteria for reverberation time. Section E4 of ANSI S12.60-2002 states "The measurements shall follow procedures in conformance with, or equivalent to, those specified for field tests in ASTM E336 [E7] or in Appendix X2 of ASTM C423 [E8]." While ANSI S12.60-2002 does not explicitly state that only rooms different in size and design need to be sampled, it does state that the sampled rooms should be evaluated based on their background noise levels (Section E3.1). It reasons that if a building has identically sized and designed rooms (including the exact same background noise levels) that the Reverberation Time and Sound Transmission Class would need to be measured in only one of the rooms. The third question is related to the PIEACP that was issued April 23, 2008 and whether a school in a very quiet and rural area can avoid the requirements that windows must meet the minimum STC rating of 35. The PIEACP offers an alternative compliance where the project team does not have to comply with the STC rating of 35 for the windows but must submit a narrative that includes the details of the long range land use plans, indicating that quiet conditions will continue. Applicable Internationally.