Entry Type ID Date Applicable Rating System Primary Credit Inquiry (LIs) Ruling (LIs) Related Addenda/LIs Related Resources Campus Applicable Internationally Applicable Country Applicability Reference Guide (Addenda) Page (Addenda) Location (Addenda) Description of Change (Addenda) "Reference Guide Correction" "100000398" "2010-04-14" "New Construction, Schools - New Construction, Core and Shell" "EQp3 - Minimum acoustical performance" "None" "None" "Green Building Design and Construction, 2009 edition" "428" "6. Calculations" "Remove the following text:\n\nCASE 2. Reverberation Time\nCore learning spaces with an enclosed volume of 20,000 cubic feet or\nlarger must meet an RT of 1.5 seconds. For each core learning space, the\nRT must be calculated separately for the 500 Hz, 1,000 Hz, and 2,000 Hz\nbands; all 3 RT values must meet the stated requirement.\nInsert the following text:\nCompliance with ANSI Standard S12.60-2002\nCore learning spaces with an enclosed volume of 10,000 cubic feet or less\nmust meet an RT of .6 seconds or less, 10,000 to 20,000 cubic feet must\nmeet an RT of .7 seconds or less, and 20,000 cubic feet or larger must\nmeet an RT of 1.5 seconds or less." "Reference Guide Correction" "100000399" "2010-04-14" "New Construction, Schools - New Construction, Core and Shell" "EQp3 - Minimum acoustical performance" "None" "None" "Green Building Design and Construction, 2009 edition" "431" "CASE 2" "Replace the third paragraph beginning with ""Determine total absorption..."" with the following text:\n\nDetermine the typical residual sound absorption factor (AR): Multiply the\nroom area by 15%. This factor accounts for the acoustically untreated\nroom surfaces and for the furnishings. Determine total absorption (A) by\nadding the residual sound absorption factor (AR) and the absorption from\nthe room materials: gypsum board walls on studs, linoleum floor, ordinary\nwindow glass, and acoustical ceiling tiles (NRC = 0.70; sound absorption\ncoefficient at 500 Hz = 0.72, from manufacturer\'s data).\n500 Hz calculation data:" "Rating System Correction, Reference Guide Correction" "100000395" "2010-04-14" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "Minimum Acoustical Performance Addenda 04/14/2010, Minimum Acoustical Performance RS Addenda 04/14/2010" "Green Building Design and Construction, 2009 edition" "Rating System: 61, Reference Guide: 423" "Requirements" "Replace the text in the box with new text as indicated in the supplemental document." "Reference Guide Correction" "100000396" "2010-04-14" "New Construction, Schools - New Construction, Core and Shell" "EQp3 - Minimum acoustical performance" "None" "None" "Green Building Design and Construction, 2009 edition" "426" "Suggested Ways to Reduce Reverberation" "Replace the fourth bulleted item with the following text:\n\nIf the classroom has a volume of over 13,500 cubic feet, acoustical panels\non both ceiling and walls may be needed to achieve appropriate\nreverberation time. For this reason, project teams with room volumes\nbetween 13,500 cubic feet and 20,000 cubic feet are strongly encouraged\nto use the methods described in ANSI Standard S12.60-2002 to confirm\nthat the room design meets the intent of the prerequisite. The option to\nconfirm compliance by showing an NRC of .7 or higher for 100% of the\nceiling area (or equivalent) is still available for rooms of this size, but it\ndoes not guarantee appropriate reverberation times. Note that carpet adds\nlittle to reverberation control, although it is useful for controlling self-noise\n(chair movement, footfalls, etc), especially in lower grade levels." "Reference Guide Correction" "100000397" "2010-04-14" "New Construction, Core and Shell, Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "Minimum Acoustical Performance Calculations Addenda 04/14/2010" "Green Building Design and Construction, 2009 edition" "428" "6. Calculations" "Replace text as indicated in the supplemental document." "Reference Guide Correction" "100001120" "2011-11-01" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010 " "BD+C RG: 433" "Definitions" "Revise the definition for core learning spaces to be, ""Core learning spaces are spaces for educational activities where the primary functions are teaching and learning and where good speech communication is critical to a student\'s academic achievement. These spaces include, but are not limited to, classrooms, enclosed or open plan), instructional pods or activity areas, group instruction rooms, conference rooms, libraries, offices, speech clinics, offices used for educational purposes and music rooms for instruction, practice and performance.""" "Global ACP" "100001278" "2012-07-06" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "X" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010" "Schools RS: 70" "Case 1, Option 2" "Add the following to the heading for Option 2: ""or Non-U.S. Equivalent""" "Global ACP" "100001279" "2012-07-06" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "X" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010" "Schools RS: 70" "Case 1, Option 2" "Add the following sentence to the end of the paragraph: ""Projects outside the U.S. may use a local equivalent to ANSI Standard S12.60-2002.""" "Reference Guide Correction" "100001105" "2011-11-01" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010 " "BD+C RG: 433" "Definitions" "In alphabetical order, add the following definition for ancillary learning spaces, ""Ancillary learning spaces are spaces where good communication is important to a student\'s educational progress but for which the primary educational functions are informal learning, social interaction or similar activity other than formal instruction.\nThese areas include, but are not limited to, corridors, cafeterias, gymnasia, and indoor swimming pools.""\n" "Global ACP" "100001280" "2012-07-06" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "X" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010" "Schools RS: 70" "Case 2" "Add the following sentence to the end of the paragraph: ""Projects outside the U.S. may use a local equivalent to ANSI Standard S12.60-2002.""" "Global ACP" "100001281" "2012-07-06" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "None" "None" "X" "Green Building Design and Construction, 2009 edition $ Green Building Design and Construction, 2009 Edition, updated June 2010" "Schools RS: 71" "Requirements" "Delete the Alternative Compliance Path for Projects Outside the U.S." "LEED Interpretation" "2040" "2008-02-12" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "The intent of this prerequisite to ""Provide classrooms that are quiet and in which teachers can speak to the class without straining their voices and students can effectively communicate with each other and the teacher."" Per the prerequisite, this is accomplished by meeting prescriptive requirements for the building envelope and interior assemblies, with the goal of achieving a maximum background noise level in classrooms and other primary learning spaces of 45 dBA. The prerequisite has a prescriptive standard that would require the corridor/ classroom assembly to have an STC rating of 45. The fundamental goal of this project is to provide small group instruction (SGI) spaces that are readily accessible/ adjacent to the ""main"" classrooms. To achieve this, small group instruction spaces have been provided as part of an ""expanded"" corridor. It is vital to the curriculum that these corridor SGI\'s be both visually and physically accessible to the classroom; in our case via 8\'-0"" wide and 8\'-0"" high fixed glazed systems for base bid and operable glazed partitions as an alternate. By providing these fixed or operable partitions between the classroom and ""corridor SGI\'s"", the effective area of the classroom is expanded, providing more one on one instruction space for students without effectively ""removing"" them from the classroom environment. It is anticipated that these partitions will be open approximately 50% of the time. The classroom, corridor and corridor SGI will all part of one acoustic zone at least half of the time. The glazing size is required to maximize the inclusion of students into the normal flow of the main classroom. In essence, we have an open classroom design that will not meet the goal of 45 dBA inside the classroom. Will this design be exempt from this prerequisite? If not, what provisions need to be made to address this design issue? This concern is echoed in ANSI S12.60-2002, Annex D2.2. It appears this prerequisite is in direct conflict with the project\'s fundamental curricular goal and is prohibiting the achievement of LEED Certification. Finally, the School District has elected an exterior wall assembly that utilizes 2"" rigid foam plastic insulation on the exterior side of the metal stud cavity in lieu of other insulation systems designed to be located in the metal stud cavity (i.e. fiberglass batt insulation, blown-in cellulose, etc.) The primary reason is so the dew point is located outside of the metal stud cavity, which eliminates the potential for mold growth associated with interior stud cavity insulation systems. We cannot achieve an exterior wall assembly STC of 50 with the 2"" rigid foam plastic insulation system. Will the 2"" rigid foam plastic insulation wall assembly STC be approved to meet the intent of this prerequisite?" "The CIR is asking about two separate areas, the use of small group instruction (SGI) corridor spaces, and the STC ratings of exterior assemblies. The question will be addressed in the order that they were presented. The SGI spaces, as described, do not appear to meet the intent of the prerequisite. It is unacceptable to have a large, direct path for noise to travel between classrooms and corridor spaces, especially given that it will likely be open 50% of the time. This presents a high probability that noise will be able to travel between classrooms. Additionally, the potential for significant noise transmission between SGIs in the same corridor (each associated with a separate classroom) was not addressed. The design does not seem to be providing learning environments that minimize acoustical distractions. If the design team is concerned that their project will not be able to meet the requirements of ANSI Standard S12.60-2002, Annexes B-D, it should be noted that there is an alternate compliance path which allows for the use of the 2003 HVAC Applications ASHRAE Handbook in lieu of the S12.60 Annexes B-D requirements. Please see the LEED for Schools Reference Guide prerequisite description for more information on this compliance path. A LEED for Schools EQp3 CIR ruling dated 12/19/2007 allows for design teams to utilize exterior assemblies that do not provide a STC 50 rating, provided that the site Day-Night Average sound level (Ldn) is verified to be lower than 60 dBA, and mechanical equipment noise attenuation is specifically addressed. Please see this CIR ruling for further information. Applicable Internationally. " "1948, 5111, 5308" "None" "X" "LEED Interpretation" "2069" "2008-04-24" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "What type of post-construction acoustical testing (e.g initial background survey, impact noise isolation, etc.), if any, is required to meet the EQp3 Minimum Acoustical Performance requirement if Option 1 (ANSI S12.60-2002) is pursued? The requirement on page 317 states that Annexes B through D are included; however, on page 322, annex E is referenced. Is annex E of ANSI S12.60-2002 part of the prerequisite requirement? If testing is required, how is the documentation handled since this is a design prerequisite?" "Post-construction acoustical testing is not a requirement for this prerequisite, if the project follows Annexes B-D. In order to determine the STC levels for certain assemblies, project teams may elect to measure the actual assembly after construction, per the methodology of Annex E5.1, but this is also not part of the prerequisite. If this is the case, the project team may defer the submission of this prerequisite until the Construction Submission Review. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2122" "2008-04-24" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "Alternative Compliance Path for EQ Prerequisite 3" "The LEED Steering Committee (LSC) has approved a PIEACP for EQ Prerequisite 3: Minimum Acoustical Performance (PIEACP stands for Performance/Intent Equivalent Alternative Compliance Path.) The alternate compliance paths listed in the PIEACP document are not intended to replace any of the existing compliance paths currently available. Rather, these methods offer alternatives to the currently available paths. Current paths shall remain in place as accepted approaches for compliance with the acoustics prerequisite. Please see the PIEACP document located on the usgbc.org website here for the PIEACP language: http://www.usgbc.org/ShowFile.aspx?DocumentID=4061 Applicable Internationally. " "10247, 2561" "None" "X" "LEED Interpretation" "2490" "2009-02-24" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "This Credit Interpretation Request is being submitted in order to establish further clarification on an alternate method(s) of compliance of the Prerequisite for Minimum Acoustical Performance. We are most interested in clarifying the sound transmission class (STC) for roof construction over core learning spaces. We have reviewed materials outlined in the 23 April 2008 PIEACP and the 13 May 2008 Errata for the 23 April 2008 PIEACP, as well as the previously submitted CIRs. The LEED certification process is for an addition to an existing suburban high school, although renovation is also in the project scope of work. The new portions of the school will include classrooms on the first and second floors, as well as Music Rooms and a TV Studio. A two-story Auditorium with a fly tower will extend above the roof height of the second level of classrooms. The site location is beyond a half mile of any major sound producing infrastructure, e.g. train lines, major highways, airport flight paths or other major potential exterior noise sources. The existing school is situated in a fully developed residential neighborhood set off by a number of blocks from the nearest commercial route. The surrounding area is highly unlikely to include any future additions or redevelopments. We believe these qualifications follow the Option 2 Alternative Compliance Method for Sound Transmission requirement as outlined in the 4/23/2008 Errata. The current design also includes interior ceiling treatment with an NRC of 0.70 or higher for all classroom and other core learning spaces as outlined in the Errata issued 4/23/08. The planned exterior wall and glazing construction will meet the original LEED for Schools Prerequisite for Minimum Acoustical Performance (EQpreq3) requirements. The roof construction over core learning spaces is currently designed to achieve an STC 40 minimum rating. We believe this rating for roof construction follows the CIR Ruling dated 19 December 2007, and is applicable to our site due to its inherit low sound qualities now and in the future. For the Music Rooms and TV Studio spaces, as well as the Auditorium and its fly area, the roof construction and exterior walls are designed to exceed the LEED requirements of the original prerequisite. We were concerned about the high potential of internal sound generation and the sensitivity of these spaces to the intrusion of external noise. We have included the acoustic best practices for interior finish and background noise requirements for these type spaces, including acoustically isolating them from the surrounding classrooms and learning spaces. We feel that due to their special nature of use, it necessitated designing these spaces to exceed the requirements of the original prerequisite and surpass the threshold of the first enhanced acoustical credit to provide the best sound control for the building users in and surrounding these spaces. Please indicate whether or not this methodology is sufficient for alternative compliance(s) with this Prerequisite. Is it possible to follow the original prerequisite requirements for certain portions of the construction while adhering to the alternative requirements from PIEACP interpretation for other portions of the building design? In addition, is it possible to use the 23 April 2008 PIEACP Alternate Compliance Method for meeting the Background Noise Level Requirement to show compliance for the Enhanced Acoustical Performance Credit (EQc9)?" "The project consists of both new construction as well as renovation work of an existing school. As described, the project will consist of classroom and core learning spaces, along with music rooms, TV studio spaces, and an Auditorium. Given the unique construction circumstances, it would be reasonable to demonstrate compliance to the prerequisite requirements based on the original requirements for select areas, and based on the alternative requirements for other areas. In regards to the Background Noise Level Requirement for EQc9, it would also be reasonable to use the alternate compliance method. However, please note that a 40 or 35 DVA sound level is required for EQc9. Also, new & renovated classroom walls must meet the STC requirements, per ANSI S12.60-2002, to achieve EQc9. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2561" "2009-03-25" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "Our project is a 160,000 s.f. public high school renovation and 10,000 s.f. addition which intends to meet all prerequisite requirements in the new addition and the background noise requirements of ANSI Standard S12.60-2002 in the existing building. We are requesting a ruling regarding the requirements necessary to meet the intent of the prerequisite in the categories of sound transmission class (STC) and reverberation time (RT) in the case of non-compliant existing conditions. We believe that in some projects such as this one, the additional scope required to meet this prerequisite as written may be prohibitive, and prevent the project from achieving LEED for Schools in an existing building. The existing conditions of the building in STC, meet the requirement for all adjacencies except for classroom to classroom and classroom to restroom. The walls at these adjacencies have an STC of 45. This rating does not meet the ANSI minimum of STC 50 between classrooms and STC 53 between classrooms and restrooms. The existing classroom partition STC of 45 is regarded as a ""good"" degree of speech privacy where normal voices in adjacent classrooms are audible but unintelligible most of the time. This degree of acoustical isolation between spaces is commonly found in existing classroom environments, and the school in its current use has not reported any difficulties with excessive sound transmission between rooms. Complying with the STC required in the ANSI Standard will require additional scope involving the building up of the existing walls between classrooms and other use spaces, from the top of the existing wall to the underside of the deck, and the building of additional, isolated walls on the sides of the existing partitions in every classroom. We would like to suggest that this scope is prohibitive to the project, as it involves rebuilding approximately half of the existing building\'s interior partitions, demolishing the adjacent plaster ceilings, and extending/removing and reinstalling all equipment and furnishings along these partitions. Considering the difficulty involved in bringing the existing building up to the ANSI standard, and the lack of reported issues in the existing building regarding sound transmission, we believe that the existing sound transmission does meet the intent of the credit to allow effective communication in the classrooms. 12 of the existing classrooms and all new classrooms will meet the RT requirements. The remaining 43 classrooms have RT ratings ranging from 0.9-1.0 at 500-2000 Hz. These ratings do not meet the ANSI requirement maximums of 0.6-0.7 at 500-2000 Hz. In order to comply with the maximum value indicated in the ANSI standard, the most feasible required additional scope involves providing a dropped acoustical ceiling tile and grid on the entire ceiling surface, and extending all ceiling equipment and fixtures to meet the new surface level. We instead recommend improving upon the existing RT conditions in the classrooms that do not meet the ANSI standard by applying mineral fiber acoustical ceiling tiles directly to the existing plaster ceilings over 50% of the ceiling surface. This will decrease the RT rating to approximately 1 second at 500 Hz, 0.8 seconds at 1000 Hz, and 0.9 seconds at 2000 Hz. Actual RT will be slightly less when the room is fully occupied. Considering the difficulty involved in bringing the existing building up to the ANSI standard, we believe that the proposed scope and improvement upon the existing RT rating does meet the intent of the credit to allow effective communication in the classrooms." "UPDATE October 1, 2012: This LEED Interpretation is no longer applicable. Refer to LI 2122 for alternatives to meeting the prerequisite requirements.\n\nIt is understood that for a building remodel/addition thorough wall acoustical performance upgrades are outside of the scope of work and likely not economically feasible. To meet the intent of the prerequisite, the project design team must to show that all new construction - and areas impacted by current construction activity meet the prerequisite requirements and that ALL of the following conditions have been met. 1. All existing spaces are within XX% of the Sound Transmission Class, XX% for the background noise requirements, and XX% for the Reverberation Time 2. That the requirements of ANSI Standard S12.60-2002, Table C.1 - ""Minimum surface area of acoustical treatment for different sound absorption coefficients, ceiling heights and reverberation times"" have been met 3. An agreement from the school district that prerequisite requirements will be met if and when future work is undertaken wherein the acoustic performance can be upgraded. Applicable Internationally." "2122" "None" "X" "LEED Interpretation" "5111" "2008-02-14" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "We are in the process of designing a new school registered under the LEED for Schools Rating System. Our team is planning to use 6"" CMU classroom wall construction - which is the preferred construction for schools of this type and location - but it appears that this material will not meet the required sound transmission class (STC) ratings for classroom partitions. Add-ons of paint, grout-filling, gypsum board, and sound-attenuation blankets are either insufficient to meet the minimum STC\'s of 50-60, or are not possible for the nature of this construction. Previous communications with USGBC Customer Service suggested that we consider acoustic block for classroom walls. However, our research indicates that this strategy will help with reverberation time requirements (which we are meeting) more than it will help with STC requirements (which we are struggling with). In choosing this wall design for durability, stability, cost-effectiveness, and contributions to energy-efficiency, we believe we were making the best decision for the balance required to attain LEED credits from all categories within our available budget. However, it appears that the only available option to meet the LEED-S STC requirements is increasing the CMU wall thickness to 8"" or 10"", which would impact materials costs, structure cost and available square footage such that we would no longer be able to earn enough credits to certify the building. Because this prerequisite does not have a history of case experience to draw from, we would like to confirm that we are interpreting the requirements properly. If so, we would ask whether it is possible to pursue an Alternate Compliance Path to meet the Intent of this prerequisite, wherein we would keep the planned 6"" CMU walls, increase their STC ratings as much as possible, and meet the rest of the prerequisite\'s requirements (window and door STC\'s, classroom reverberation time and background noise levels) as normal. If using an alternate compliance as described above is not sufficient to meet the intent of the prerequisite, we would appreciate any guidance you could provide on how to cost-effectively meet the technical requirements as written." "The CIR is requesting an alternate compliance path to this credit, where the minimum STC rating is not achieved but the structural wall system that has been chosen to meet a wide variety of criteria is improved to achieve the maximum STC rating possible for that type of construction. Consistent with the CIR ruling published 12/19/07 for this credit, the prescriptive requirements can be exempted when other criteria are being met. If 6-inch thick CMU classroom wall construction is the preferred for schools of this type and location, there should be existing walls that are virtually identical to the proposed constructions. Therefore, several of these walls should be field tested to quantify their actual noise reduction. If the measured noise is NIC (Noise Isolation Class) 45 or more, then it complies with the STC 50 minimum rating requirement for classroom walls according to ANSI S12.60-2002 [4.7 (3)]. Applicable Internationally. " "1948, 2040, 5308" "None" "X" "LEED Interpretation" "5160" "2008-10-21" "Schools - New Construction" "EQp3 - Minimum acoustical performance" "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. " "None" "None" "X"