When using the Integrative Process, the best way for the LEED AP to assess the impact of indoor and outdoor water consumption in a Building Design and Construction project is to perform a preliminary water budget analysis before the completion of schematic design. This analysis should include the following steps1:
Identify the project’s water sources and uses, such as potable water, reclaimed water, rainwater, graywater, blackwater, irrigation, cooling towers, etc.
Estimate the baseline water consumption for each use based on the applicable codes, standards, and benchmarks.
Identify potential water conservation strategies that can reduce the demand or increase the supply of water, such as low-flow fixtures, native landscaping, rainwater harvesting, graywater reuse, etc.
Evaluate the feasibility, cost-effectiveness, and environmental benefits of each strategy using a life-cycle approach.
Select the most appropriate strategies and document how they inform the design decisions and meet the project goals.
Compare the projected water consumption with the baseline and calculate the percentage reduction.
Performing a preliminary water budget analysis before the completion of schematic design allows the LEED AP to identify opportunities for water efficiency and innovation early in the design process. It also helps to optimize the integration of water systems with other building and site systems, such as energy, materials, indoor environmental quality, etc. Moreover, it supports the achievement of other LEED credits related to water efficiency, such as WE Prerequisite 1: Outdoor Water Use Reduction, WE Prerequisite 2: Indoor Water Use Reduction, WE Credit 1: Outdoor Water Use Reduction, WE Credit 2: Indoor Water Use Reduction, WE Credit 3: Cooling Tower Water Use2.
References:
Understanding Integrative Design in LEED v41
LEED v4 for Building Design and Construction2