For projects with multiple independent HVAC systems, portions of the building can be flushed out separately, as they are completed, as long as no additional construction work occurs in an area where a flush-out has begun. Completed areas should be isolated from those under construction per SMACNA IAQ guidelines for Occupied Buildings Under Construction, which is the same standard that defines the requirements for EQc3.1 (see Resources).

The flush-out or testing will not affect installation of furniture and furnishings, as this can happen during or after the flush-out or testing, however, prior to beginning flush-out or testing, the following work should be completed to ensure that no toxins are reintroduced into your project space:

Develop an IAQ management plan detailing your project’s approach to EQc3.1 (if your project is pursuing it) and this credit.

Require that your contractor submit an IAQ Management Plan early in construction, before interior work has begun. The plan should detail the approach to this credit, as well as EQc3.1 if both credits are being pursued. Either of these credits can be pursued independently; EQc3.1 is not a prerequisite for EQc3.2. However, pursuing the credits in tandem is the most effective way to ensure the best IAQ at the time the building is turned over to the owner. 

If considering IAQ testing, design the building in a way that maximizes the likelihood of passing the testing. This should include specifying low- and no-VOC materials as part of the EQc4: Low-Emitting Materials credits, at a minimum.

Include the requirements for building flush-out or IAQ testing in the IAQ Management Plan and the project specifications. If you are pursuing both EQc3.1 and EQc3.2, then include the requirements for both in a single plan.

If planning to pursue Option 2, also plan to pursue EQc3.1 and all of the EQc4: Low-Emitting Materials credits to ensure the best chances of passing the IAQ testing on the first try. 

Consider whether your HVAC system will be able to power a flush-out while maintaining temperature and humidity levels during seasonal extremes in a timely fashion, without major scheduling impacts. A total of 14,000 cubic feet of outside air must be exchanged for every square foot of floor area. The amount of outside air prescribed during a phased flush-out (0.3 CFM) may be several times greater than the normal rate required for a project’s occupancy, based on ASHRAE 62.1-2004, as required by EQp1: Minimum IAQ Performance. 

Depending on which of the two options you choose for this credit (see Schematic Design), you should start to consider the following two things during predesign:

Do not include land-clearing debris or excavated soil or rock in your calculations. Even if diverted from landfill, it is not to be included in the credit calculations. Contractors often think that trees and stumps are still part of the diverted waste, but take them out of the LEED submittal template and supporting documentation if the contractor includes them.