This CIR describes our methodology for developing baseline and design water use for a LEED NCv2.2 project. This project includes one existing, renovated building with a large new addition. It will be occupied by the General Assembly and will include committee rooms for internal or public meetings, offices, press room, cafeteria. The general assembly is only in session for 4 months, which is when the highest occupancy will occur. The other 8 months will be a reduced count. First we have determined the average building occupancy based on visitors and full/part time staff in session and out of session per the following assumptions 1) In session: a) New addition Offices will be used 100% during session at 100% capacity. The number of regular building occupants is based on desk count per the preliminary drawings. The four large committee rooms will be used 100% during session at 100% capacity. There will be 30 elected officials (building occupants already accounted for in the number of regular building occupants) and the rest visitors. Meeting rooms and small committee rooms will be used only for internal meetings. Single occupant toilets adjacent to the large committee rooms will be used during session only by committee members. Other employees and visitors will use the core toilets. b) Existing building Offices will be used 100% during session at 100% capacity. The number of regular building occupants is based on desk count per the preliminary drawings. The ballroom will be used 100% during session at 100% capacity. There will be 30 elected officials (building occupants already accounted for in the number of regular building occupants) and the rest visitors. Journalists will be using the pressroom only during session, approx. 2hours per day. Meeting rooms and small committee rooms will be used for internal meetings. Single occupant toilets adjacent to the ballroom will be used during session only by committee members. Other employees and visitors will use the core toilets. 2) Off session: a) New addition Offices will be used 50% of the time off session at 10% capacity. The four large committee rooms will be used 50% of the time off session, with 50% capacity. We assume 3/4 building occupants, 1/4 visitors. Meeting rooms and small committee rooms will be used for internal meetings. Employees and visitors will use the core toilets. b) Existing building Offices will be used 50% of the time off session at 25% capacity. The ballroom will be not used off session. Meeting rooms and small committee rooms will be used for internal meetings. Employees and visitors will use the core toilets We have differentiated use of core toilets and single occupant toilets because two different flush rates are applied. Single occupant toilets are low-flow single flush (1.3 gpf) while the core toilets are dual-flush (1.1/1.6 gpf). We have multiplied the full-time equivalent building occupants and visitors during session by 1/3 and out of session by 2/3 to finally get the aggregate total FTE occupants and visitors for WEc3. We have considered the peak FTE occupants and visitors during session to calculate the minimum number of secured bicycle racks and showers to comply with SSc4.2. Please advise if this methodology is acceptable.
The CIR is requesting verification that the presented method of calculating FTE occupants is acceptable. In general this approach seems reasonable for what is a relatively complex occupancy pattern. When this project is submitted for review, be sure to include an explanation with at least this level of detail. It would also be beneficial to explain if the single occupancy restrooms are only accessible by certain users (i.e. key access) or if the assumption was that only certain occupants would be likely to use them. Please note that the LEED Submittal Template allows for the applicant to input a custom occupancy type (in addition to the standard FTE/Student/Vistior/etc. categories. This may allow for a simpler calculation than trying to lump together multiple occupancy types to create a single FTE value. The water savings of dual flush toilets in commercial and public settings has not yet been proven; there is a need to verify that dual flush toilets are in fact used as intended by consumers, and further research is necessary.