What baseline does LEED use to calculate indoor water use reduction?

LEED calculates indoor water use reduction based on the baseline established by the Energy Policy Act of 1992. This legislation sets forth specific criteria that define maximum allowable water consumption for various types of plumbing fixtures, including toilets, urinals, showers, and faucets. By utilizing this baseline, LEED establishes a standard against which projects can measure their water efficiency improvements.

The Energy Policy Act of 1992 plays a crucial role in promoting water conservation by encouraging the use of fixtures that comply with these efficiency standards, helping to reduce overall water demand in buildings. This aligns with LEED’s goals of promoting sustainability and resource efficiency.

In contrast, the other options focus on different aspects of water management and plumbing standards but do not serve as the baseline for indoor water use reduction calculations in the LEED framework. The ASHRAE Standard relates to energy efficiency but is not the primary reference for water use; the International Plumbing Code sets regulations for plumbing systems but does not provide the specific consumption levels used for LEED's water use reduction assessments; and the WaterSense Program, while promoting water-efficient products, is not the foundational tool used for calculating indoor water use reductions in the LEED rating system. Thus, the correct reference is indeed the Energy Policy Act of