Explanation
Installing dual-flush toilets can significantly reduce indoor water demand. Dual-flush toilets have two flush options: a half flush for liquid waste and a full flush for solid waste. By using less water for liquid waste, these toilets can reduce overall water consumption by up to 30%, helping to achieve the owner's water reduction goal. References: LEED Green Associate Candidate Handbook, U.S. Green Building Council resources

Explanation
Climate change is weighted the most in the LEED rating systems because it is considered the most urgent and significant environmental challenge facing humanity. Climate change is caused by the accumulation of greenhouse gases in the atmosphere, which trap heat and alter the global climate patterns. Climate change can have severe consequences for human health, biodiversity, water resources, food security, and social equity.
LEED projects can help mitigate climate change by reducing greenhouse gas emissions from building operations and materials, as well as enhancing resilience and adaptation to climate impacts. The LEED impact categories and point allocation process assigns 35% of the total points to climate change. References: LEED v4 Impact Category and Point Allocation Process Overview2; LEED v4 BD+C Reference Guide, Introduction, page 9

Explanation
Flush out process is performed to remove volatile organic compounds (VOCs) from the indoor air after construction or renovation12. VOCs are chemicals that can evaporate at room temperature and cause health problems, such as headaches, nausea, and irritation3. Flush out process involves supplying 100% outdoor air to the building for a certain period of time or until a certain amount of air changes are achieved12.
References:
Flush-out documentation | LEEDuser1
Building flushout - option 2 | LEEDuser2
Volatile Organic Compounds' Impact on Indoor Air Quality | Indoor Air Quality (IAQ) | US EPA3

Explanation
Open grid pavement, also known as permeable pavement, allows water to drain through it, reducing runoff and recharging groundwater supplies. It also tends to be lighter in color than traditional asphalt, which means it absorbs less heat from sunlight. This helps to reduce the urban heat island effect, which is a phenomenon where urban areas are significantly warmer than their rural surroundings due to human activities. References:
LEED Green Associate Candidate Handbook, U.S. Green Building Council resources

According to LEED v4, the commissioning authority (CxA) should be contracted before the end of the Design Development (DD) phase and should be involved in the project team from early in the Schematic Design (SD) phase1.