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Start by assessing efficiency
To meet this prerequisite, you will need to assess the efficiency of your basic indoor plumbing fixtures, such as faucets, water closets, urinals, and showerheads, and determine how much potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. is consumed relative to a LEED baseline case. If your current bathroom, kitchen and janitorial closet fixtures are already highly efficient, you will probably meet the prerequisite. If your installed fixtures are older and exceed the baseline, you’ll need to modify them.
Baseline depends on when fixtures were installed
The baseline for the prerequisite is established by calculating how much water the project building fixtures would use, based on actual occupancy figures and usage patterns, if it were fully compliant with IPCInternational Plumbing Code/UPCUniform Plumbing Code 2006 plumbing codes displayed in Table 1. This baseline also takes into consideration the installation date of the relevant fixtures. For plumbing systems substantially completed before 1993, the baseline is set at 160% of the IPC/UPC-compliant figure; however, for systems substantially completed in 1993 or later, the baseline is set at 120% of the water usage with code-compliant fixtures. Buildings with a mixture of fixture installation dates will use a weighted average to determine the final baseline.
Inventory installed fixtures
To determine compliance, you will need to inventory all installed fixtures, and document their flow and flush rates and date of installation. It is very important to determine the correct baseline setting, so carefully consider whether you have completed any major renovations to your bathrooms and associated plumbing systems in 1993 or later. If you have a pre-1993 building and have simply replaced bathroom fixtures without performing a more complete renovation of the bathroom structure and plumbing system, you’re allowed to use the 160% baseline for all of your fixtures.
Installing flow or flush restrictors, such as faucet aerators or dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste solid or liquid. flushometers, will carry relatively low costs. Expect significantly higher costs if you must replace the existing toilets to accommodate more efficient flushometers. Depending on water and sewer rates, plumbing retrofits like these can pay off relatively fast, however.
Pay careful attention to the credit form
The key to successful documentation of this credit is proper setup of your building fixture groups in the LEED Online credit form. This part of the form can be confusing and is often misinterpreted. Carefully review the instructions on creating these fixture groups and make sure that the credit form is displaying the correct values for occupancy and number of fixtures in your building when you are finished. USGBC has provided a guide that helps clarify many common issues—be sure to review this (see Resources).
If you have a pre-1993 building, and are planning on performing a major bathroom renovation as part of the overall LEED project, be sure to register the project through LEED Online before starting any retrofitting in order to claim the less stringent 160% baseline.
Start by gathering this information
- How many different types of each fixture are installed in the building? Are fixture specs or product data sheets available for the installed fixtures?
- What is the date of substantial completion for plumbing? Was the project initially built before 1993? If so, have there been renovations since 1993 that affected plumbing fixtures?
- What opportunities exist for low-cost upgrades?
- What upgrades will have the greatest effect on reducing water consumption?
- Are there any high-intensity water uses, for example, a fitness center with showers?
- Are rebates or incentives available to offset upgrade costs?
Legend
- Best Practices
- Gotcha
- Action Steps
- Cost Tip
USGBC
Excerpted from LEED 2009 for Existing Buildings: Operations & Maintenance
Copyright © 2009 by the U.S. Green Building Council, Inc. All rights reserved
WE Prerequisite 1: Minimum Indoor Plumbing Fixture and Fitting Efficiency
Required
Intent
To reduce indoor fixture and fitting water use within buildings to reduce the burdens on potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems.1 supply and wastewater systems.
Requirements
Reduce potable water use of indoor plumbing fixtures and fittings to a level equal to or below the LEED 2009 for Existing Buildings: Operations & Maintenance baseline, calculated assuming 100% of the building’s indoor plumbing fixtures and fittings meet the plumbing code requirements as stated in the 2006 editions of the Uniform Plumbing Code (UPC) or International Plumbing Code (IPC) pertaining to fixture and fitting performance. Fixtures and fittings included in the calculations for this credit are water closets, urinals, showerheads, faucets, faucet replacement aerators and metering faucets.
The LEED 2009 for Existing Buildings: Operations & Maintenance water use baseline is set depending on the year of substantial completion of the building’s indoor plumbing system. Substantial completion is defined as either initial building construction or the last plumbing renovation of all or part of the building that included 100% retrofit of all plumbing fixtures and fittings as part of the renovation. Set the baseline as follows:
- For a plumbing system substantially completed in 1993 or later throughout the building, the baseline is 120% of the water use that would result if all fixtures met the codes cited above.
- For a plumbing system substantially completed before 1993 throughout the building, the baseline is 160% of the water use that would result if all fixtures met the codes cited above.
If indoor plumbing systems were substantially completed at different times (because the plumbing renovations occurred at different times in different parts of the building), Set a whole-building average baseline by prorating between the above limits. Prorate based on the proportion of plumbing fixtures installed during the plumbing renovations in each date period, as explained in the LEED Reference Guide for Green Building Operations & Maintenance, 2009 Edition. Pre-1993 buildings that have had only minor fixture retrofits (e.g., aerators, showerheads, flushing valves) but no plumbing renovations in or after 1993 may use the 160% baseline for the whole building.
Demonstrate fixture and fitting performance through calculations to compare the water use of the as-installed fixtures and fittings with the use of UPC- or IPC-compliant fixtures and fittings, as explained in the LEED Reference Guide for Green Building Operations & Maintenance, 2009 Edition.
Develop and implement a policy requiring economic assessment of conversion to high-performance plumbing fixtures and fittings as part of any future indoor plumbing renovation. The assessment must account for potential water supply and disposal cost savings and maintenance cost savings.
FOOTNOTES:
1. Potable water is defined as water that is suitable for drinking and is supplied from wells or municipal water systems.
Potential Technologies & Strategies
Reduce indoor plumbing fixture and fitting potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. usage through automatic water control systems. Install, where possible, water-conserving indoor plumbing fixtures and fittings that meet or exceed the UPCUniform Plumbing Code 2006 or IPCInternational Plumbing Code 2006 fixture and fitting requirements in combination with high-efficiency or dry fixture and control technologies.
Technical Guides
Uniform Plumbing Code (UPC) 2006, Section 402.0: Water-Conserving Fixtures and Fittings
The Uniform Plumbing Code defines water-conserving fixtures and fittings for water closets, urinals and metered faucets. This ANSI-accredited code safeguards life, health, property and public welfare by regulating and controlling the design, construction, installation, quality of materials, location, operation and maintenance or use of plumbing systems.
International Plumbing Code (IPC) 2006, Section 604: Design of Building Water Distribution System
The International Plumbing Code defines maximum flow rates and consumption for plumbing fixtures and fittings, including private lavatories, public lavatories (metering and those other than metering), showerheads, sink faucets, urinals and water closets.
EPA WaterSense
WaterSense, a partnership program sponsored by EPA, certifies products that meet its water conservation thresholds.
Web Tools
How to Conserve Water and Use it Effectively
Includes information on practices for conserving water and using water efficiently for residential users, system operators, agricultural users, and for industrial/commercial users. Both engineering and behavioral practices are described.
Rocky Mountain Institute (RMI)
This portion of RMI’s Web site is devoted to water conservation and efficiency. The site contains information on commercial, industrial and institutional water use, watershed management and articles on policy and implementation.
Terry Love’s Consumer Toilet Reports
This Web site offers a plumber’s perspective on many of the major low flow water efficient toilets used in commercial and residential applications.
Water Closet Performance Testing
This site provides two reports on independent test results for flush performance and reliability for a variety of different toilets.
U.S. DOE, Federal Energy Management Program
This site provides good information on basic water efficiency challenges, best practices and federal, state, and local resources.
Water: Doing More with Less
This article from Environmental Building News discusses building water efficiency.
WATERGY version 3.0
WATERGY is a spreadsheet model that uses water/energy relationship assumptions to analyze the potential of water savings and associated energy savings.
Publications
LEED 2009 Water Use Reduction: Additional Guidance
This document from USGBC offers guidelines to help you properly set up fixture usage groups in the LEED Online credit form, avoiding common mistakes associated with the water-efficiency prerequisite and credit.
Plumbing Renovation Economic Assessment Policy
All Options
All options require documenting a policy that mandates economic assessment of conversion to high-performance plumbing fixtures and fittings as part of any future indoor plumbing renovations.
Water Fixture Inventory
Option 4: Plumbing Fixtures Installed Before 1993
A plumbing fixture inventory needs to include manufacturer, model number, flush or flow rate and date of installation in project building.
15 Comments
LEED Online v3 Beta Form Calculations
Seems like there may be issues with how the LEED Online v3 Form calculates water use reduction; it certainly generates diffferent numbers than the v2009 Template. Be cautious about using early versions of the Form, and stayed tuned...
Jenny Carney replied Director, YRG sustainability Aug 21 2009
An update on the LEED Online V3 Form - USGBC reports that a fixed version will be available around September 1.
Actual LEED Credit Screen Captures
This is a great site with extremely helpful material (thanks!). Is there though some way of getting screen by screen images of the actual Credit templates as it appears in LEED Online. This is our first effort and it appears that we can't see the templates until the prerequisites and minimum requirements are completed and sent in. We're trying to see the actual submission requirements line by line. We've registered the project and see the prereq's but don't see a way to the credits at this point. Screen captures would be ok if there is no other way.
Thanks,
John
Jenny Carney replied Director, YRG sustainability Jan 24 2010
John, it's a really good idea to scrutinize the credit forms early in the project, so your instincts are good there.
To access the credit forms once the project is registered, a member of the project team with adequate permissions (I know "administrator" level works for this, but not sure of the other designations) will need to navigate to the "Scorecard" tab, and then click the "Add/Remove Credits" button.
From here you'll be able to check all the credits you want to have show up in your project-specific scorecard. After you hit the update button, a list of all checked credits will be available, and you can follow the link associated with each credit to see the form.
At first, a "collapsed" version of the form will show up, and as you click through on the form which compliance option you are pursuing, submittals and verifications associated with that option will pop up. It's a good idea to warn your team that some submittal elements are hidden until you click on the applicable option, so that they don't accidentally miss information about what's need to show compliance.
Hope this helps, and let me know if you're able to navigate all this.
Water Efficiency Calculation question
HI, We are going at this LEED process ourselves here at Tufts Health Plan and I have a minor question regarding LEED baseline for shower heads. My question: We have about 1700 employees here and only about 350 employees use the gym/shower each day. When doing the baseline calculation for LEED, Do we use 100% of the employees in the calculation or do we use only the 350? When doing the calculation using the Delta's Green Project Estimator, They did 100% of the employees for both U.S. Average and LEED in the calculation. Thank you for your help.
Jenny Carney replied Director, YRG sustainability Feb 07 2010
Hi Bruce - the standard assumption is that 10% of FTEs will go ahead and get showered any given day in buildings with showers. When filling out the submittal form, this percentage is applied on the backend, so you should enter the total FTEs. The form will automatically apply the 10% assumption - for example, if you enter 100 FTEs into the initial table in the form, the table for flow fixtures will then show 10 daily uses for showers. At present, it doesn't appear that the form accommodates a custom value for the number of showers per day, though if you could justify a certain value that differs from the standard 10% usage rate you may be able to make a case.
Fixture data/spec sheets
My project building was built in 1876 (!) and has not had a major renovation since 1993 (it did have one in the 1980s). I do not have bath faucet spec sheets; however, if I add aerators to the existing faucets, can I include the spec sheets for those alone?
I found aerators that provide 0.5 GPM, which is lower than what you would get with a new faucet and much cheaper.
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Mar 02 2010
You can indeed Janna - ultimately the aerator is what determines the flow rate of the fixture, so that is the critical element for documentation in the case of faucets. No need to dig up specs on the faucets themselves if you have them on the aerators.
Efficiency calculation
We are planing on pursuing LEEDS for one of our Garment manufacturing facilities. At the moment we are trying to see the status of our water usage compared to the baseline.
We bought the factory recently and therefore, we do not have any manufacturer documents even though our fixtures are installed after 1993. In calculating the water usage is it necessary to calculate it based on the data of flow measurements of a 20% fixtures? because i was able to see a Version 2 template where they wanted us to fill the actual flow rates of fixtures enabling it to compare.Can you tell me whether Version 3 is different from that? Furthermore, we do know the total water consumption as we have used meters. Is it possible for us to use those data to establish the actual case rather than using data of fixture flow rates to arrive at the actual water usage?
Thank you.
Corinna Kester replied Consultant, Sustainable Buildings and Operations, KEMA Mar 19 2010
Hi Rashid -
You cannot use whole building water meter data to satisfy the requirements of WEp1; you must do a calculation based on flush/flow rates. The documentation path for individual fixture flush/flow rates is the same in both LEED 2008 and LEED 2009, as follows:
"For each fixture type that differs from UPCUniform Plumbing Code or IPCInternational Plumbing Code efficiency requirements (because of either lesser or greater water consumption rates), provide manufacturer cut sheets verifying flow rates for each fixture type, measured flow rates for a 20% representative sample of each fixture type, or evidence of the installation date of each fixture type for which worst-case default values were used."
Jason Franken replied LEED Consultant, YRG sustainability Mar 19 2010
Rashid, before you start conducting flow/flush rate testing of your building fixtures, you may want to spend a little time researching the fixtures to see if you can track down manufacturer information. Most plumbing fixtures and fittings will have manufacturer names stamped on them, and some will even include model numbers or flow/flush rates in terms of gallons per minute (gpm) or gallons per flush (gpf). Start by doing a building walkthrough and inspecting all of your fixtures. Organize them by fixture type and manufacturer and count up all of the installed fixtures. Look for manufacturer information on the fixture and carry a small mirror with you to make it easier to look at the back of flush handles or lavatory aerators. It may be much easier to try to contact manufacturers to acquire valid product information than to go through the process of testing a representative sample of 20% of your fixtures. If you're unable to track down manufacturer information, check back here to get assistance on conducting compliant flush/flow rate testing.
Link between Occupant and Water Forms
In LEED 2009 EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. Online, once the values are entered in PI Form 3 regarding "Occupant and Usage Data," shouldn't they automatically populate the corresponding fields of the WE Prereq 1 Form regarding "Minimum Indoor Plumbing Fixture and Fitting Efficiency?" Specifically, I'm not seeing the FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. entries from Table FIF3-3 and the Transient (Student / Visitor) entries from Table FIF3-4 carry over to the "Daily Occupancy" and "Fixture Groups Definition" tables in the "Performance Calculation" section of WE Prereq 1. Anyone else experiencing this too?
Corinna Kester replied Consultant, Sustainable Buildings and Operations, KEMA Mar 19 2010
Hi Douglas -
If I understand your question correctly, it is actually part of the design of the Template that the FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. entries from the Project Information Forms do not carry over to the "Fixture Group Definition" table in WEp1. This is because buildings can have complex fixture groups, depending on building space use and occupancy patterns, or depending on fixture renovation patterns.
The performance calculations need to be able to account for this complexity, so the relevant tables are not set to auto-complete; they must be filled in manually by the project team.
J Douglas Dietrich replied Mar 19 2010
Corinna,
Thank you for the quick response. So it is normal that the transient number is coming in from the PI form, but the FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. number isn't?
I have been able to verify that, as you said, in the WEp1 form the user can enter the FTE and gender ratio information.
We appreciate your help in understanding the nuances of how the new LEED Online features and navigation works.
Best regards,
Doug
Post '93 Construction - Requirements?
Hi - My building is just over a year old. Am I correct in that all I need to do to meet this prerequisite is:
1-Verify construction date and fixture types (either through construction docs or inventory) with no calcs required; and
2-Develop a policy for conversion to high-performance fixtures that includes a simple economic/payback assessment?
Thanks for any help anyone can provide - I'm new to this and want to be sure I'm not overlooking anything.
Regards,
-Dianne
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