When replacing flushometers, make sure that the existing water closet or urinal bowl is capable of providing the flush rate specified on the new hardware. This information should be available on product data sheets or by request from the manufacturer.
If retrofitting is required, begin with low-cost fixtures and fittings, such as 0.5 gpm faucet aerators, high performance or dual-flush flushometers, and low-flow showerheads.
If performance calculations indicate that water use exceeds the baseline case, find opportunities for water-use reduction through replacement of fixtures and fittings with high-efficiency options.
The key to successful documentation of this credit is proper setup of your building fixture groups in the LEED Online credit form. This part of the form can be confusing and is often misinterpreted. Carefully review the instructions on creating these fixture groups and make sure that the credit form is displaying the correct values for occupancy and number of fixtures in your building when you are finished. For additional guidance on setting up these fixture usage groups, please reference guidelines published by USGBC (see Resources).
If your building supports visitors or retail customers, you will need to calculate the average number of each of these occupant types that use your facilities on a daily basis.
Complete performance and baseline calculations in the LEED Online credit form using fixture data and occupancy and usage information. For plumbing systems substantially completed before 1993, the baseline is set at 160% of the IPC/UPC-compliant figure; however, for systems substantially completed in 1993 or later, the baseline is set at 120% of the water usage with code-compliant fixtures.
If indoor plumbing systems were substantially completed at different times for different parts of the building, use Option 4 (see below) to complete performance calculations using a weighted average water-use baseline.
