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) "LEED Interpretation" "10095" "2011-08-01" "Schools - New Construction" "EQc9 - Enhanced acoustical performance" "The STC 50 rating between core learning spaces required by ANSI S12.60-2002 challenges a wall assembly that has been the standard for public school construction in Ohio for decades. The construction of Otsego PK-5 is no exception as an 87,000 square foot combination masonry bearing and steel frame construction requiring durability, student security, ease of maintenance, and structural integrity on a predetermined budget developed and co-funded by the Ohio School Facilities Commission.\nThe design team has enlisted the services of a professional acoustician and reviewed the options for STC 50 wall construction. We have been advised against sand and grout filling CMU walls due to the difficulty it creates for future renovation, the unnecessary weight it adds to the building, and the uncertainty of knowing whether or not the fill was done properly. We feel that heavy weight block (48 lbs. or more) is not a practical building material due to the weight it adds to the building as well as increased construction time and labor. Additionally, enlarging the wall thickness between classrooms is not feasible due to the predetermined square footage requirements of the building set by the Ohio School Facilities Commission. The School District and design team strongly feel that metal stud and gypsum wall board construction, either as furring or stand alone construction will not provide the longevity required of classroom walls in a public school system and will quickly become a maintenance issue.\nANSI S12.60-2010 has acknowledged this design/construction dilemma by including a footnote in Table 4 (the equivalent of ANSI S12.60-2002 Table 2) associated with the STC 50 requirements for #Other enclosed or open-plan core learning space#etc.# which states, #A 20 cm (8#) concrete masonry unit wall having a surface weight area density of at least 180 kg/m2 painted and sealed on both sides, acoustically sealed at the entire perimeter and extending from the floor slab to the structural deck above, is an acceptable alternate assembly that conforms to the intent of being Table 4 # Minimum STC ratings required for single or composite wall and floor-ceiling assemblies that separate a core learning space from an adjacent space.\nPlease note that ANSI S12.60-2010 Table 4 has also included an exception to the STC 53 requirement for core learning spaces adjacent to toilet rooms that states,# These requirements do not apply to toilets opening only into the core learning space and used only by occupants of the core learning space#, a condition that was found acceptable by a Credit Interpretation Ruling dated 4/21/2009 under LEED for Schools 2007 IEQ Prerequisite 3, Minimum Acoustical Performance.\nOtsego Local School District and the design team respectfully request that the above referenced normal weight 8# CMU wall construction now accepted by ANSI S12.60-2010 be considered suitable for compliance with the STC 50 rating requirement between core learning spaces associated with LEED for Schools 2009 IEQ Credit 9 Enhanced Acoustical Performance." "The project team is asking whether a wall construction (20 cm (8 in) concrete masonry unit wall having a surface weight area density of at least 180 kg/m2 painted and sealed on both sides, acoustically sealed at the entire perimeter and extending from the floor slab to the structural deck above) now accepted by ANSI S12.60-2010, is suitable for compliance with the STC 50 requirement for this credit. \n Yes, the use of the 2010 version of ANSI S12.60 is acceptable for this credit. " "None" "None" "LEED Interpretation" "5196" "2009-02-24" "Schools - New Construction" "EQc9 - Enhanced acoustical performance" "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"