Can testing be done over various days?
Yes, as long as it complies with the EPA standard.
For IAQ testing, how many sample points are necessary in non-mechanically ventilated spaces?
This is left to the discretion of the industrial hygienist or other qualified professional who is performing the testing and employing the EPA Standard.
Should we install furniture and furnishings before IAQ testing or flushout?
It's optional. In the past that has been unclear, and in an addendum issued 10/1/12, USGBC clarified that it is optional to install furniture and furnishings before IAQ testing or flushout for IEQc3.2. The word "optionally" has been inserted in the last paragraph of page 466 in the LEED BD&C reference guide, before "including furniture and furnishings."
For LEED NC addition projects, do existing non-renovated areas need to be flushed-out or tested?
No, not if the project team is only certifying the addition, per se, as a separate LEED project. But the addition should be isolated from the existing, unrenovated areas in accordance with the SMACNA IAQ Guidelines for Occupied Buildings under Construction.
Do non-regularly occupied areas such as bathrooms and corridors have to be flushed-out?
Yes. All occupied gross floor area (both non-regularly occupied and regularly occupied) must be included.
Do the outdoor air minimum quantities have to be met for each individual space, or for the building square footage as a whole?
Ideally, the flush out will be designed to provide the minimum volume to each individual space, and the LEED Reference Guide indicates that teams must take reasonable measures to ensure there is no obvious short-circuiting of the airflow. However, the requirements only address the "total air volume," so, for LEED credit compliance purposes it is only necessary to quantify the total outside air volume supplied to the entire building.
Should a parking garage be included in a flush-out, if it is in a basement and not fully open to the outdoors?
No, parking garage space should not be included in this credit.
Is it possible for the flush-out start date to vary by ventilation zone?
Yes. Areas served by completely separate ventilation systems—where air serving these spaces is not mixed with air serving any other spaces—can be flushed independently, as long as each such area is also isolated completely from all non-flushing areas per SMACNA guidelines.
Is it possible to combine Options 1 and 2 for different spaces in the same building?
No, Options 1 and 2 cannot be combined to meet the credit requirements.
I'm confident we have enough space allotted for recycling, but how much detail should I go into in documenting expected volume?
LEEDuser recommends providing a brief narrative that demonstrates you have estimated the volume following something like a Solid Waste Assessment. Resources such as those found at the California Integrated Waste Management Board can be useful. See case studies and approaches in the Establishing A Waste Reduction Program at Work participant's manual and in the waste disposal rates for Public Admin.