Use Worksheet S-8 Building Water Calculator to calculate building water use for base and design. This also shows EPA required flow and flush fixture rates, and example fixture performance values.
Implementation in the Design Process:
In Predesign and early design, develop a water efficiency improvement goal meeting or exceeding the guideline requirements.
Through the design process adapt the water efficiency goal, document it in the program, and communicate the water efficiency goal to all design team members. The water efficiency goal should also be documented in the specifications for the project.
Provide annual water use calculations showing the reduction in water use compared to code. Use the total daily water requirements from the Minnesota Plumbing Code and the Energy Policy Act as the basis of the calculations.
In the project’s construction documents confirm or revise calculations from the design development phase and specify compliant appropriate fixtures. Clearly indicate the water efficiency goal. Review submittals and verify compliance with specifications and confirm installation onsite.
Documentation required for this guideline includes a completed Appendix S8 – Building Water Calculator. This evaluates the reduction from a base-case water scenario for regulated fixtures.