Explanation
The increase in air temperature in a developed area resulting from the dark surfaces of roadways, parking lots, and tarred rooftops is known as heat island effect. Heat island effect is a phenomenon whereby urban areas experience higher temperatures than rural areas due to the absorption and re-emission of solar heat by man-made surfaces. Heat island effect can have negative impacts on human health, energy consumption, air quality, and climate change. Some strategies to reduce heat island effect include increasing vegetation cover, using reflective or green roofs, using cool or permeable pavements, and enhancing natural ventilation.References: LEED v4 BD+C Reference Guide, Sustainable Sites, page 35 ; EPA Heat Island Effect website 1

LEED prerequisites are the minimum requirements that a project must meet in order to be eligible for LEED certification. Prerequisites are mandatory for all projects and cannot be substituted or waived. If a project does not meet a prerequisite in one credit category, it does not qualify for certification, regardless of how many points it earns in other categories123.
A project that does not meet a prerequisite in one credit category does not forfeit all points in the same credit category, as points are awarded for meeting optional credits, not prerequisites. A project cannot file a CIR (Credit Interpretation Request) to seek clarification or exception for a prerequisite, as CIRs are only applicable for credits. A project cannot substitute a prerequisite from an alternative rating system, as prerequisites are specific to each rating system and reflect the minimum standards for that system

A charrette is an intensive, multi-disciplinary workshop with the aim of developing a design or vision for a project or planning activity. Charrettes are often conducted to design such things as parks and buildings, or to plan communities or transportation systems. A charrette should take place at the beginning of the project, when the design team can engage with all the stakeholders, including the client, users, consultants, contractors, regulators, and community members. A charrette at this stage can help to:
Establish clear goals and objectives for the project
Identify opportunities and constraints for the site and program
Generate creative and innovative ideas and solutions
Foster collaboration and consensus among diverse perspectives
Reduce conflicts and delays during later phases of the project
Enhance communication and trust among the project team
The other options are not appropriate phases for a charrette. Post commissioning is too late to influence the design or planning of the project. During the design process, some decisions may have already been made or some stakeholders may have been excluded. During the construction process, changes may be costly or impractical to implement. Reference: : Charrette

Composting toilets operate without water, making them ideal for reducing potable water consumption. LEED promotes such innovative technologies for achieving water efficiency credits.