Merrill Hall is a reconstruction of the 17,022 gsf main educational building for the Center for Urban Horticulture at the University of Washington. The building includes public spaces, lab facilities, academic offices, a library, classrooms, and a separate, but attached greenhouse. We have implemented an Indoor Air Quality Management Plan for the construction phase in accordance with Credit EQ 3.1 and plan to perform a pre-occupancy flush of the building per EQ 3.2. Our building includes both mechanically and naturally ventilated portions, and our question relates to requirements for the naturally ventilated spaces. The naturally ventilated spaces comprise the classrooms and the separate, but attached, greenhouse. We consider that these areas do not require mechanical flushing to meet the requirements of this credit based on the following. The naturally ventilated classrooms have been finished with low-emitting finishes meeting the requirements of Credits EQ 4.1, 4.2, and 4.3. Casework that contained urea-formaldehyde composite wood was held at a warehouse for four weeks before installation and is only installed in the labs with mechanical ventilation. Some bamboo flooring was donated to the project that does contain added urea-formaldehyde in the glue. This will be installed in a naturally ventilated area, but has already been on site off-gassing for over a year. These spaces will have been finished out and naturally ventilated for approximately two months before the building is occupied. The attached greenhouse will be constructed of glass, steel, and concrete and will contain no VOC-emitting finish materials. Since these naturally ventilated spaces contain no ductwork, are finished with low or no-VOC-emitting finishes, and in the case of the classrooms, will have had sufficient time to off-gas any volatiles prior to occupancy, we consider these spaces do not need mechanical flushing to prevent indoor air quality problems. In addition, these areas will be isolated to prevent cross-contamination during flushing of the mechanically ventilated spaces. Please confirm that our approach to pre-occupancy flushout of Merrill Hall meets the intent of EQ Credit 3.2.
LEED provides two ways to achieve EQ Credit 3.2. The naturally ventilated classrooms can achieve this credit by: (1) demonstrate that the two months of natural ventilation flush-out provided an equivalent of supplying a total air volume of 14,000 ft3 of outdoor air per ft2 of floor area while maintaining an internal temperature of at least 60o F and, where mechanical cooling is operated, relative humidity no higher than 60% (per EQc3.2 ruling dated 9/8/04); or (2) performing baseline indoor air quality testing as referenced in the LEED-NC v2.1 Reference Guide or EAc3.2 credit ruling dated 10/8/02. The greenhouse does not require the flush out or testing because no absorptive materials for mold growth or VOC absorption/off-gassing are incorporated in the structure or interior finishes. Applicable internationally.