We are writing with a request for review of a question very similar to others already raised by other applicants, regarding the Prerequisite for Minimum Acoustical Performance in an elementary school, a question to which I hope you will give further consideration. We are planning and designing the substantial renovation of a Lower School, K-5, for a private girls' school. The existing buildings were built in 1972 as an open-plan school, and have been used that way, with some modest alterations, ever since. For pedagogical, operational, and specific institutional cultural reasons, all thoroughly and painstakingly considered by the school and the design team, the school has determined that they will be best served by retaining a degree of visual connection and generous passage between teaching spaces, while for the first time dividing the individual classrooms from one another to reduce the potential for unhelpful acoustic distraction. As planned, this will involve building solid walls between classrooms, but with broad areas of fixed glass along the corridor walls, permitting view from an open library and circulation space at the core of the building, into and through the classrooms to the exterior. Plans also include solid sliding partitions, easily operable by a child, approximately 8 feet wide by door height, interconnecting some of the classrooms to permit the rather frequent multi-class meetings that are part of the school's daily routine. It appears unlikely, if not impossible, that the glass area and easily-operable sliding doors will meet the STC criteria required for separation of teaching spaces by the Minimum Acoustical Performance Prerequisite, and yet these design elements are of critical importance to the school's specific curricular and pedagogical needs. The building plans also include all-new energy-efficient mechanical and electrical systems, new higher-performance window systems, all-new interior finishes specified for LEED conformance, a much-increased full-building insulation system, re-roofing for solar-load reduction and amelioration of the heat-island effect, and many other environmentally responsible components. By our rough tabulations, the project should score somewhere near the boundary between Basic and Silver certification, and would almost certainly be LEED certified if not for its failure to satisfy the acoustic separation component of the Minimum Acoustical Performance Prerequisite. This means that this project may not be LEED certified, despite the fact that in many key respects_ not least of which is that it is a renovation of an existing building on an existing site_ it is exemplary in its approach to the prudent use of materials and to sustainable, environmentally responsible operation. This is not a case where inattentive design or sloppy construction may lead to degradation of the intended acoustic environment, but one where there has been thorough and thoughtful consideration of the relative merits of connection and separation in the context of this school's approach to teaching. The school has been enormously successful using the open-plan arrangement for over thirty years, and cannot now fully abandon that model for teaching. At the same time, they are wholeheartedly committed to being environmentally responsible. How, within the LEED Rating System for Schools, can we accomplish both goals, and recognize the school's environmental commitment with the appropriate LEED certification? Must we adhere to the specific acoustic separation criteria of the Prerequisite for Minimum Acoustical Performance, or are there other measures ensuring speech intelligibility and acoustic comfort that, in this set of circumstances, would be acceptable? Is the alternative compliance path for Indoor Environmental Quality, Prerequisite 3: Minimum Acoustical Performance, described in your recent bulletin, intended to permit an application based on such alternative criteria?
The project is seeking guidance on how to meet the prerequisite requirements based on the specific design and programmatic considerations for the project and its classrooms. The project is noting challenges in meeting the STC criteria. It is unclear however if the project has evaluated compliance for the project based on the recently released LEED for Schools EQp3 Performance/Intent Equivalent Alternative Compliance Path (PIEACP), dated April 23, 2008. The alternative compliance methods noted in this PIEACP does provide other means to meeting the earlier established requirement for STC, while still meeting the intent of the prerequisite. This document can be downloaded from the USGCB website and should assist the project in meeting the prerequisite requirements. The intent of the PIEACP is to optimize the acoustical isolation for instructional spaces that employ teaching strategies or methods which inherently cannot meet specified STC ratings. The project will meet the prerequisite if all reasonable measures are employed to limit sound transmission within the circumstances of the project; application of these measures can be demonstrated by submission of a narrative as directed in the PIEACP. Compliance with the STC ratings specified in EQ P3 is not required under this alternative compliance path. Applicable Internationally.
Related Addenda (Corrections & Interpretations)