Rating System

LEED BD+C: Schools

Rating System Version

v2 - Schools 2007

Inquiry

We are seeking relief from the reverberation time (RT) requirements of EQ Pr3. Our project is the renovation of a historic academic building originally constructed in 1932 for an independent school in New England. The classrooms are a bit unique, and that is proving to be a challenge for meeting the acoustics prerequisite, even with the new PIECAP. Each classroom is about 350 s.f., and is both the instructor\'s office as well as the teaching area. In the center of the room is a large oval table where 13 students and one instructor sit, facing one another during instruction time. The specific "Harkness" tables used in the classrooms, the number of students in a class, and the principle of teacher "ownership" of classrooms has been a tradition at the school for over 100 years and there is no plan to change this. The ceilings are existing to remain plaster, the floors are hardwood, with the occasional area rug in some classrooms. The window wall is plaster - other walls in the room have a mix of slate blackboard, plaster, bookcases and wood paneling - all hard surfaces. The classrooms have a large amount of historic wood paneling and moldings that would inhibit acoustical modifications. (We can provide pictures if that would be helpful.) The project acoustical consultant tells us that the classrooms, as presently set up, will not meet the RT requirements set forth in LEED. For the size of these rooms (less than 10,000 cf of volume) the reverberation time requirement is to be less than 0.60 seconds. This is the average of the 500, 1K and 2K octave bands. Measurements show that, for the rooms without carpet on the floor, the reverberation times are generally 1.0 or 1.1 seconds, with one result being 0.90 seconds and one result being 1.2 seconds. For a medium size classroom with a large area rug the reverberation time is 0.80 seconds. The building renovation includes replacement of the HVAC system and windows, but the work in the classroom areas will be largely cosmetic - we\'re not replacing ceilings, walls or floors in most of these rooms. The school is not interested in making significant changes to these spaces such as acoustic tile ceilings, or other treatment - after all they have served their purposes just fine for 76 years. If the intent of the prerequisite is to provide spaces where "students can effectively communicate with each other and the teacher", these rooms certainly meet that intent. It\'s just that the prerequisite does not seem to anticipate this sort of space. This issue has been discussed at length with the school, and they have committed to having sizable area rugs in the rooms so that the excess reverberation would be only a modest amount over the requirement. Typically this would reduce RT to around 0.80 seconds. Given the teaching method (face to face, around a table), the fact that these are existing conditions in a historic building, and that we are committing to improving the worst situations by adding area rugs, we ask if our proposed actions meet the intent of the prerequisite? The outcome of this issue will have an impact on the school\'s ultimate decision to pursue LEED Certification for the project.