Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.2

Inquiry

This project inquiry applies to Water Efficiency Credit 3.2. For affordability, we installed faucets and water closet fixtures that satisfy the requirements for Credit 3.1 but at 80 psig water pressure their ratings do not satisfy the flow rates required by Credit 3.2. In order to achieve the required further reductions we are testing the use water saving devices such as water closet dams, to reduce the water usage for the 1.6 gallon per flush water closets. The amount of water per flush for the urinals were adjusted downward by the installing contractor using a valve that cannot be tampered by the general staff or public. Furthermore, the urinals are working fine at this lower flow rate. Our flow measurements at the faucets document that the actual flow rates enable the water systems to easily satisfy Credit 3.2. A major reason for this is that the water pressure at the fixtures is considerably less than 80 psig-we estimate it to be less than 40 psig. Essentially, the city water service and building water distribution system in this renovated building are playing an important role in lowering water usage. We also reduced construction costs and reused building materials by not replacing and upsizing the water service and building water distribution system. The first part of our inquiry is can we get credit for modifying fixtures (using toilet dams and adjusting internal valves) to enable them to consume less water. The second part of our inquiry is whether documented water flow measurements may be used in the LEED Application for Water Use Reduction Credits. We propose two forms of documentation: water flow measurements at the fixtures; tracking the building\'\'s water meter and comparing the total building water use against the Baseline usage. This approach is consistent with the LEED Existing Buildings approach of documenting actual water usage.