Credits WE 3.1 & WE 3.2 are the same except for the percent (%) reduction. If one completes the requirements and implementation for WE 3.2 – Water Use Reduction – 30%, they would also receive a point for WE 3.1. Thus, earning two points toward LEED accreditation for the project. The posts for WE 3.1 and WE 3.2 are exactly the same except for the percent reduction.Water Use Reduction – 30%Intention:
- Maximize water efficiency
- Reduce burden on municipal water supply
- Reduce burden on wastewater system
Implementation:
- Method: Use special fixtures and sensor/metering controls.
- ( fixture/flowrate in Gallons Per Minute [GPM] )
- Shower/2.5 (lowflow/1.8)
- Lavatory/2.5 (lowflow/1.8) (ultra lowflow/0.5)
- Kitchen Sink/2.5 (lowflow/1.8)
- Faucets/2.5
- Aerator/2.5
- Water Closet/1.6 (lowflow/1.1)
- Dual Flush Water Closet/1.6 (lowflow/0.8)
- Composting Toilet/0.0
- Urinal/1 (lowflow/0.5)
- Non-Water Urinal/0.0
- For calculations, consider:
- DO NOT include irrigation water
- Only applicable for the following fixtures:
-
- water closets
- urinals
- lavatory faucets
- showers
- kitchen sinks
- Daily Residential Usages:
- 1 person 5 uses per day of flush and flow fixtures
- Also use high-efficiency fixtures above, dry fixtures, occupant sensors.
- Consider reusing stormwater and graywater for non-potable uses.
Codes/Standards Applied:
- Energy Policy Act 1992 (different from the EPA)
Extra Credit:
- For both WE3.1 & WE3.2: 40% (instead of 20% or 30%) reduction of water usage
OR
- Process and non-regulated water use savings is at least 10%
Submittal Phase:
- design
Links from Reference Guide:
- Composting Toilet Reviews
- Terry Love’s Consumer Toilet Reports
- Water Efficiency Manual for Commercial, Industrial, and Institutional Facilities
- Water Measurement Manual: A Water Resources Technical Publication
- Water Wiser: The Water Efficiency Clearinghouse
Other Water Efficiency Credits
17 Comments On This Post
I believe you have an error in the ID portion of the above. To gain and ID in WEc3.2 you need to accomplish WEc3.1 and WEc3.2 and also increase water conservation to 40% (not 100%) as stated above.
Also, the way I read the LEED NC2.2, page 143 is that it is possible to achieve an ID point as described above AND to achieve a second ID point for a 10% reduction in process water.
Take a look.
Can a project earn 2 ID points by having both a 40% reduction in water usage AND a 10% non-regulated water use savings?
Mitchell,
No, i believe it’s either or.
-Pat
does outdoor landscape water fountains, pond included as plumbing fixtures in the WE water calculations
I don’t think that outdoor stuff counts as part of plumbing fixtures as intent states “maximize water efficiency within buildings…”
Although a fountain or other water feature located within a building lobby might confuse that definition… but that sort of fixture doesn’t really “reduce the burden on municipal water supply and wastewater systems”.
My personal interpretation would be that it would have to count as part of the calculation, but my knee-jerk reaction would be to delete it and put in a nice Japanese Zen garden in sand.
Thanks Franco.
Any clarification out there for “Process and non-regulated water use savings is at least 10%”. From the guide it sounds like this is allowing EPAct regulated household items to come into play. So lets say 37% reduction from the regulated items would garner 2 points and 16% reduction from non-regulated items would be another point for exemplary?
WES-
No, you could get an IDc1 point for an extra 10% reduction (40% total) following the REGULAR credit requirements per the EPAct.
-OR-
You could get an ID point if you demonstrate only 10% water saving for process and non-regulated water consuming fixtures. These non-regulated items could be things such as dishwashers, clothes washers, etc w/ a government backed Energy Star rating. See pg 141 (2nd to last paragraph on pg)
The calculations for this 10% exemplary performance are done in a similar fashion to the regular calculations of WEc3.
hmm, thanks Cassi. not sure if i will ever remember which ones are non-regulated…hope i don’t get a question about that.
Can some-one please tell me HOW IMPORTANT IS THIS CREDIT ON leed exam. especially memorizing formulas etc etc. Even though this credit is short but the info is almost as complicated as Credit AE.
Well know the following:
How to calculate FTE (remember to add in average daily transients)
– EPACT fixture flow rates and durations
– Watersaving lowflow and no flow rates and durations
– Understand that for submittals men and women are treated as equals ie. if there are 60 men and 40 women calculations will be for 50 men and 50 women. In other words a 1 to 1 ratio.
– Know that special circumstances do allow a different ratio of men to women in the calculations if occupancy is very unbalanced (ie all girls school)
– Know how non-potable water sources can contribute to reduction in potable water usage
– understand that non-potable sources may depend on occupancy usage…. a school might have a significantly less amount of graywater available during the summer months because students are not there.
-know what the energy policy act of 1992 is
– know how to calculate a basline
– Know how to calculate water reduction from the baseline
Thats what i can think of off the top of my head. Its not so hard once you get all the details memorized. If you need help with actual calculations let me know.
Parker: “Understand that for submittals men and women are treated as equals ie. if there are 60 men and 40 women calculations will be for 50 men and 50 women. In other words a 1 to 1 ratio.” I am still unable to get this part. Can you please explain?
Does that mean that if we are given number of men v/s number of women in the building. We don`t need to do the water usage calculations twice?? Number doesn`t matter???
Reenu: yes and no, basically you still need to do calculations for both men and women, because they have different usage rates for some fixtures (water closets and urinals). But instead of using the actual ratio of men and women, you simply split the FTE down the middle. For instance if you have 100 people, it doesnt matter what the male to female ratio is, you would use 50 men in your calculations and 50 females. Hope that makes sense.
Thanks Parker. Also, good luck for Today`s exam. I am sure you will pass:)
can anyone explain what the LEED reference guide means when they use the term lavatory? especially in WEc3, table 3 it is used as a single term (conventional lavatory vs low flow and ultra low flow) but elsewhere it is used as lavatory faucet. Is lavatory defined as bathroom sinks?
i am confused and could use some clarification. thanks!
I do not think we need to take 1 to 1 ratio for men and women if you know exactly how many men and women uses the space.
For example if the space is designing for 200 people and you do not know how many are men and women, then you need to take 100 men and 100 women for calculations.
For example if the space is designing for 80 men and 120 women, then you need to use actual numbers for men and women in the calculations.
The reference guide actually says to compare process and non-regulated savings to regulated usage. “If the process and non-regulated water use savings is at least 10% of the total design REGULATED water use, the project team is eligible for an Innovation in Design point.”
This is different than reducing process and non-regulated usage by 10% of itself. For example, you could reduce the volume of potable water that your cooling towers use by 10% of the volume that your bathrooms and kitchen sinks use.
Anyone else see it this way?