For LEED BD+C Location and Transportation (LT) Credit: Surrounding Density and Diverse Uses, Option 1: Surrounding Density, the project team must measure:
* Residential density in dwelling units per acre (DU/acre) or dwelling units per hectare (DU/ha).
* Non-residential density based on floor area ratio (FAR).
* The density must be measured within a ¼-mile (0.40 km) radius of the project boundary.
This credit promotes high-density development and reduces urban sprawl, thereby improving access to amenities and public transportation.
(Source: Official LEED BD+C Reference Manual)

Green Infrastructure (GI) and Low-Impact Development (LID) rainwater management strategies improve upon the conventional approach for rainwater management by replicating a site's natural hydrology. GI and LID are design approaches that use various practices to mimic the natural water cycle and reduce the negative impacts of development on the environment. They aim to preserve, restore, or create natural features that can capture, infiltrate, evaporate, or reuse rainwater on site, rather than conveying it to a centralized stormwater system. By doing so, they can reduce runoff volume and peak flow, improve water quality, enhance groundwater recharge, increase biodiversity, and create more attractive and resilient landscapes. Therefore, option A is the correct answer. The other options are not true for GI and LID strategies. Discharging rainwater at a faster rate (option B) would increase the risk of flooding, erosion, and pollution downstream. Increasing a site's impervious surface (option C) would reduce the infiltration and evaporation of rainwater and increase runoff and heat island effects. Providing a greater volume of rainwater detention (option D) would not necessarily improve the site's hydrology, as detention is only a temporary storage of rainwater that does not address the runoff quality or quantity issues. For more information on GI and LID rainwater management strategies, you can refer to the LEED v4 Reference Guide for Building Design and Construction1 or the Green CE course on Rainwater Management for LEED v4.1 Projects2.

The scope of analysis in Materials and Resources Credit, Building Life-Cycle Impact Reduction, Option 4.
Whole-Building Life-Cycle Assessment is a cradle-to-grave assessment. This means that the life cycle assessment (LCA) covers all stages of the building's life cycle, from the extraction of raw materials (cradle) to the disposal or reuse of the building components at the end of their service life (grave)1. The LCA must include the following life cycle stages: product stage, construction process stage, use stage, and end-of-life stage2. The LCA must also account for the environmental impacts of the building's structure and enclosure, as well as any other building elements that are permanently attached to and share service systems with the building2. References:
* Whole building life cycle assessment through LEED v4
* Building life-cycle impact reduction | U.S. Green Building Council

According to the LEED v4: Building Design + Construction Guide1, Option 2 of the Surrounding Density and Diverse Uses credit requires the project to be within walking distance of at least 10 diverse uses. The guide also states that "walking distance is defined as the distance that a pedestrian must travel between origins and destinations without obstruction, in a safe and comfortable environment on a continuous network of sidewalks, all weather-surface footpaths, crosswalks, or equivalent pedestrian facilities." Therefore, the documentation must include walking routes from the project to each use to demonstrate that the distance requirement is met. References:
* LEED v4: Building Design + Construction Guide
* CI-v4.1 LTc2: Surrounding density and diverse uses | LEEDuser

Water Efficiency (WE) Prerequisite: Indoor Water Use Reduction requires at least 20% savings over the baseline.
* The project initially achieves 18% savings, which does not meet the prerequisite.
* With the rainwater harvesting system, the total savings reach 28%, exceeding the minimum 20% prerequisite.
* A 28% total reduction qualifies the project for two points under Water Efficiency (WE) Credit:
Indoor Water Use Reduction.
The type of metering does not impact the points awarded for this credit.
(Source: Official LEED BD+C Reference Manual)