Hello
We have a Commercial Interior located in a Base Building which have a rain water collection tank. Water is treated and is used for irrigation and for urinals and toilets of the common area restrroms. Building allowed to the our project to connect the rain water system for urinals and toilets for the inside restroom. We know we can include the rain water in the water credir but we have little information about the system.
Building owner shared with us the tank capacity and the equipment information. Can we sustain the credit whit this information??
Base building is a Core and Shell v3 LEED Gold.
Thank you for your help
emily reese moody
Sustainability Director, Certifications & ComplianceJacobs
LEEDuser Expert
476 thumbs up
June 26, 2018 - 3:05 pm
Hi Luis,
Can you ask the base building for the documentation they provided as part of their CS certification? Having that information as supporting documentation for your project should help tremendously, and should also give you insight as to how to make the calculations specific to your space.
I would advise that once you think you have determined a way to calculate your project's savings, you can contact GBCI and ask if your calculation method is appropriate. http://www.gbci.org/contact
They usually cannot confirm if your calculations will be accepted (for that, you would likely need to submit a CIR), but they should be able to advise if you're going about the calculations in the correct manner.
Hope that helps.
Luis Carlos Perez Plazas
June 27, 2018 - 9:19 am
Hello Emily. Thank you for your help.
Unfortunately, the base building owner didn’t give us so much information. We asked the document of the credit, but we never had an answer. They only gave us a document where the process is described (collection zones, treatment plant, tanks capacity, rainwater network).
When we were asking permission to connect the project to the rainwater base building network, we gave them the flow that we need for the urinals and toilets. When we had the permission, they gave us a letter where they guarantee this flow through the year, I don’t know if it's enough for the credit documentation.
Thank you for your advice, when the Credit is ready I will contact to the GBCI.
Thank you for your time and help
emily reese moody
Sustainability Director, Certifications & ComplianceJacobs
LEEDuser Expert
476 thumbs up
June 27, 2018 - 12:30 pm
Ok, it's unfortunate that they're not more helpful.
In the FAQ section for this credit, there are some general guidelines in how to go about calculating the system. It states the following: "Once the annual design case water is calculated, nonpotable water can be subtracted to determine total water savings."
That said, I would probably fill out the water use calculator provided for the credit as a normal project. Once completed, I would take the annual total from the design case (what you're installing), and subtract out the water used for the flush fixtures only that is shown in your calculator. Do this in a separate document that also includes a narrative describing what you did. The end total after you subtract the flush fixture water should give you the new design case total you should use for your calculation. You can then use that number to compare to your baseline water use number shown in the calculator, and determine your percentage of savings.
Luis Carlos Perez Plazas
July 3, 2018 - 11:27 am
Yes, we are thinking to document in that way. We find the calculator for CI doesn't have the option to include the savings by rain water, then we must calculate the saving in a separate way and include this after with a narrative. Maybe in leedonline form we can include the savings but I don't know yet. When we finish the documentation, we will let you know.
Thank you for your help
ESD Engineer
Energy & Sustainability EngineerEnvironmental Systems Design, Inc.
3 thumbs up
December 11, 2018 - 5:24 pm
Hi Luis -
I have a similar project. Were you able to achieve the additional reduction? If so, how did you show the calculations for alternative water use?