A flush-out is a process that is conducted prior to building occupancy and removes indoor airborne contaminants by thoroughly exhausting old air and replacing it with fresh outdoor air. A flush-out is one of the options for achieving the LEED Indoor Air Quality Assessment credit, which aims to reduce indoor air quality problems resulting from construction or renovation and promote the comfort and well-being of occupants1. A flush-out requires that the building be supplied with a total air volume of 14,000 cubic feet of outdoor air per square foot of gross floor area while maintaining an internal temperature of at least 60°F and no higher than 80°F and relative humidity no higher than 60%. The flush-out can be done before or during occupancy, but the latter option requires a minimum ventilation rate and duration2. A flush-out can help to remove volatile organic compounds (VOCs), particulate matter (PM), and other pollutants that may be emitted from construction materials, finishes, furnishings, and equipment3.

The project team's strategy of using low-flow toilet fixtures and integrating non-potable water strategies for the building interior falls under the Water Efficiency category. The Water Efficiency category addresses the conservation and management of water resources in buildings and landscapes. Using low-flow toilet fixtures reduces the amount of potable waterused for flushing toilets, saving water and energy. Integrating non-potable water strategies for the building interior involves using alternative sources of water, such as rainwater, graywater, or reclaimed water, for non-potable purposes such as toilet flushing or irrigation, reducing the demand for potable water and wastewater generation. The other options are not categories that this strategy falls under. Innovation is a category that recognizes exemplary performance, innovative strategies, or pilot credits that are not covered by existing LEED credits. Sustainable Sites is a category that addresses the selection, development, and maintenance of project sites in ways that minimize environmental impacts and enhance human health and well-being. Optimized Process Water Use is not a LEED category or credit. References: LEED Green Associate Candidate Handbook, page 31; USGBC [Water Efficiency], page
1-2.

The best way to prevent a building's indoor pollutant(s) is to eliminate or control pollutants at the source.
Indoor pollutants are substances or particles that can adversely affect the indoor air quality (IAQ) of a building and the health, comfort, and productivity of the occupants. Indoor pollutants can originate from various sources, such as building materials, furnishings, cleaning products, combustion appliances, outdoor air, or occupant activities. Eliminating or controlling pollutants at the source can prevent them from entering or spreading in the indoor environment, which can reduce the exposure and risk for the occupants. Some examples of source control strategies are: using low-emitting materials, installing local exhaust ventilation, sealingcombustion appliances, implementing green cleaning practices, and prohibiting smoking13. References: LEED v4 Green Associate Candidate Handbook1, EPA's Indoor Air Quality3

The Integrative Process is most effective during the early design stage of a project. This is when key decisions about the project are being made that can have a significant impact on its sustainability performance. By considering sustainability objectives from the outset, teams can identify opportunities for synergies and cost savings that may not be apparent later in the project. References: LEED Green Associate Candidate Handbook, U.S. Green Building Council resources

Building commissioning is a quality assurance process that begins during the design phase and continues through construction, occupancy, and operation of the building. It ensures that the building's systems are designed efficiently, installed correctly, and operate as intended. The commissioning process involves a series of inspections, tests, and adjustments of building systems, followed by a review of the system design and operation with the building's operations team. References: LEED Green Associate Candidate Handbook, U.S.
Green Building Council resources