Our project is community services foundation for homeless and disadvantaged persons providing a wide variety of community support services. As such we have identified four unique and separate user groups who will use this facility: Group 1:Clinic & Learning Center (visitors); Group 2: daily dining room (guests & volunteers); Group 3: 5 day per week staff and Group 4: 7 day per week staff. Each group has significantly different annual work days in the facility and therefore noticeably different water usages per fixtures. However, the LEED Online v2.1 WE Credit 3 Letter Template does not allow more than one Annual Work Days number to be considered when calculating the base and design case water use calculations. Alternative methods for calculating water usage have been submitted through prior CIRs and accepted by the USGBC for unique project situation but none of the alternative methods proposed seem to fit our project\'s specific circumstances. Therefore, we propose the following alternative method that accounts for each user group\'s annual work days and fixture uses by normalizing each group\'s male and female head count to one Annual Work Days count of 365 days per year. Examples: Group 1 works 260 day per yr or 260/365 = 71.23% of work days Group 2 works 365 days per yr or 365/365 = 100% of work days Group 3 works 250 days per yr or 250/365 = 68.49% of work days Group 4 works 351 days per yr or 351/365 = 96.16% of work days Using each of the above listed percentages, we then multiply each normalized percentage of work days per group by the total number of daily uses for both men and women by bathroom fixture. e.g.: If Group 1 has 58men each using the toilet once a day, the normalized usage would be (58*.7123) = 42 *1usage/day = 42 uses per day. The same formula would be applied to each fixture type for each user group\'s men/women head counts. These \'prorated\' or normalized male/female fixture uses allow for accurate, baseline and design case calculations using one normalized Annual Work Days of 365 days. This will enable us to correctly tabulate water use reductions using the established LEED-Online template. . Please confirm this method is acceptable for use on WE Credit 3 and clarify what supporting documentation should be submitted with the Credit Template. If this method is not acceptable please provide an alternative method for calculating this credit with more than user group total annual work days.
The project is proposing to derive a representative estimate of annual water usage for each user type by normalizing the fixture usage according to number of work days. The approach, as described, is acceptable for developing a combined estimate for diverse occupant types. This approach will essentially generate a composite # uses per fixture based on the four different user groups using the building. To support this approach in your submittal, you should provide the complete calculations used to develop the composite uses per fixture. Also, you should be sure to use a 50/50 male/female ratio unless there is strong evidence of an alternate ratio for the projected life of the building. Applicable Internationally.