Rating System

LEED BD+C: Schools

Rating System Version

v2 - Schools 2007

Inquiry

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?