Our LEED NC v2.2 registered project includes additions and major renovations to an existing office/laboratory building. We wish to pursue WEc2 - Innovative Wastewater Technologies on the project and would like to know if our strategy for compliance is acceptable in pursuit of OPTION 1. Within the new additions, we plan to install high-efficiency fixtures including high efficiency dual flush and low flow water closets and urinals for all new addition flush fixtures to contribute towards wastewater reduction. Within the existing building, the flush water closet fixtures are 3.5 gallons/flush rated and the urinals are 1.5 gallons/flush rated. We plan to replace a combination of the water closet fixtures with high efficiency low flow type and upgrade the urinal flush valves with new, high efficiency low flow type to reduce the sanitary discharge. The combination of new addition fixtures and modifications to the existing fixtures will reduce the total site sewage conveyance by greater than 50% below the current sewage conveyance of conventional fixture standards in the new buildings and no modifications to the existing fixtures. However, this credit references the Energy Policy Act of 1992 baseline water quantity flow requirements. We would like to use the gallons/flush ratings of the existing water closets and urinals as the baseline discharge for the existing fixtures in our calculations for WEc2 - Innovative Wastewater Technologies. We believe we are meeting the intent of the credit by significantly reducing the generation of wastewater and the potable water demand.
No, existing fixtures cannot be used as the baseline for calculations for WEc2. For LEED calculations, the baseline case is defined as the building with fixtures that meet the Energy Policy Act requirements, NOT the actual fixtures existing prior to retrofit. The design case is defined as the building with the actual fixtures installed. This ensures that there is a consistent baseline across all LEED projects. Please refer to the LEED calculation methodology under WEc2 in the LEED-NC v2.2 Reference Guide and LEED-NC v2.1 WEc3 CIR ruling dated 4/19/2004 for additional information and guidance. Applicable Internationally.