Volatile Organic Compounds (VOCs) (D) are chemicals often found in building materials, such as paints, adhesives, and finishes, and are associated with health risks, including asthma, chronic obstructive pulmonary disease, and certain cancers. VOCs release harmful gases that contribute to indoor air pollution, and LEED encourages using low-VOC materials to protect occupant health. PVCs (B) and CFCs (C) are harmful to the environment but are not directly linked to these health conditions.

A vegetated roof primarily contributes to the Sustainable Sites (SS) Credit: Heat Island Reduction. Green roofs reduce the heat island effect by minimizing roof surface temperatures through vegetation, which absorbs less heat than conventional roofing materials. This helps lower building cooling costs and mitigates urban heat effects. Sensitive Land Protection (B) and Site Assessment (C) are unrelated to roof treatments, while Light Pollution Reduction (D) deals with exterior lighting strategies.

Rainwater collected from the building roof would be the most appropriate nonpotable water source for use in a cooling tower. This is because rainwater is generally cleaner than other nonpotable sources and does not require extensive treatment before use. Additionally, using rainwater can help to reduce stormwater runoff, providing an additional environmental benefit.
Reference: LEED AP Building Design + Construction (LEED AP BD+C) V4 resources 1

This factor is included in the lamp lumen uplight calculation, because it represents the amount of light that is emitted downward by the fixture, which does not contribute to light pollution1. The lamp lumen uplight calculation is used to determine the percentage of total luminaire lumens emitted above horizontal, which must not exceed the maximum allowed values for each lighting zone2.

The answer is C. A high evapotranspiration rate will result in a higher demand for potable water use in irrigation. Evapotranspiration is the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants. The higher the evapotranspiration rate, the more water is lost from the soil and plants, and the more irrigation is needed to replenish the moisture. The other options will not increase the demand for potable water use in irrigation. A sparsely planted area will have less vegetation and less transpiration, reducing the water demand. A drip irrigation system will deliver water directly to the plant roots, minimizing evaporation and runoff, and saving water. A rainwater harvesting system will collect and store rainwater for irrigation, reducing the reliance on potable water sources. For more information on outdoor water use reduction and irrigation efficiency, you can refer to the LEED v4 Reference Guide for Building Design and Construction1 or the WaterSense Water Budget Tool2.