0090008291

CALCULATING INDOOR WATER USE REDUCTION FOR LEED

1 AIA HSW/SD CE Hour & 1 LEED Specific BD+C, ID+C or Green Assoc GBCI CE Hour

Alex Spilger, LEED AP BD+C, ID+C, EBOM [email protected] www.greenstepeducation.com

© GreenCE, Inc. 2012

AIA Course Number: ggs00a | GBCI Course ID: 0090008291

Please note: you will need to complete the conclusion quiz online at greence.com to receive credit

Indoor Water Efficiency for LEED

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Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.


An AIA Continuing Education Program Course Format: This is a structured, web-based course with a final exam. Course Credit: 1 AIA Health Safety & Welfare (HSW), Sustainable Design (SD) CE Hour Completion Certificate: A copy is sent to you by email or you can print one upon

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Design professionals, please remember to print or save your certificate of completion after successfully completing a course conclusion quiz. Email confirmations will be sent to the email address you have provided in your GreenCE.com account.



GBCI CE Program

Calculating Indoor Water Use Reduction for LEED GBCI Course ID: 0090008291

GreenCE, Inc.

Approved for 1 GBCI LEED Specific Hour for LEED Green Associates or 1 LEED Specific BD+C GBCI CE Hour or 1 LEED Specific ID+C GBCI CE Hour


Course Description This one hour audio online course includes practical knowledge regarding the WE prerequisite and credits for Indoor Water Use Reduction calculations. We will review and demonstrate how to properly complete the LEED calculations for Indoor Water Use Reduction by means of the Credit Template. The presenter will directly train participants to complete these LEED credit calculations by hand, thus providing a solid foundation for the variables, assumptions and calculation methodologies referenced by the credits and built into the Credit Template. Participants will then actively locate and complete the credit template in 4 different application examples using various scenarios. By performing these calculations, participants develop a framework for these credits which enables improved utilization of the LEED NC, CS, Schools, ND, and CI Rating Systems. We will conclude the program today with a brief 10 question quiz.


Learning Objectives By completing this course, the design professional will be able to:

1. Explain how the WE Indoor Water Use Reduction credits differ between various LEED Rating Systems and indicate system synergies.

2. Describe LEED Indoor Water Use Reduction credit calculation inputs, variables, assumptions & equations.

3. Calculate LEED WE Credits by hand, including the baseline and design case flush and flow rates to determine indoor water savings.

4. Complete the LEED WEp1 Credit Form through 4 practice problems utilizing a variety of fixture combinations.


Materials This course will walk you through how to download the LEED v3 WE template You can also do this now: 1. Go to: http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1447 2. Select LEED NC 2009 (v3) WE 3. Save file 4. Select Folder: wep1 5. Select File: wep1_dya.pdf


Agenda

1. Introduction to Indoor Water Usage in Buildings

2. How LEED addresses Indoor Water Efficiency for different Rating Systems

3. Understanding LEED Credit Calculations and the inputs, variables,

assumptions & equations involved

• Practice Problems 1

4. Completing Indoor Water Usage Calculations

• Practice Problems 2, 3 & 4

5. Discussing Return on Investment (ROI) for various water saving strategies

6. Q &A and concluding remarks


U.S. Building Impacts

Presenter

Presentation Notes

This chart represents the impact that commercial buildings have on water usage as compared with other areas. As you can see buildings have an significant impact on the environment. There are many green building strategies that serve to reduce this impact. Water is becoming a bigger and bigger issue as global population rises and puts strains on the potable water supply. LEED requires projects to reduce indoor water usage below a baseline which helps alleviate the global water supply issue.


Green Building Benefits

Presenter

Presentation Notes

Green Building strategies can reduce the impact of buildings on the environment in several major areas, water efficiency included. Green building can reduce water usage by over 40% when compared with standard code compliant fixtures


Water Usage within Commercial Buildings

Flush Fixtures

Flow Fixtures

Landscape Irrigation

Process Water

Presenter

Presentation Notes

Strategies for reducing water usage include efficient flush and flow fixtures such as waterless urinals, dual flush toilets, flow restrictors on bathroom sinks and low flow showers. In addition to water savings through indoor plumbing buildings can save water through efficient irrigation practices. Strategies include drip irrigation, rain water harvesting, non-potable water supplied by a public agency (also referred to as Purple Pipe water) and weather sensing systems which are capable of adjusting the irrigation demand by sensing moisture in the soil. Other weather sensing systems can tie into national weather forecasting to preemptively lower water usage before a large storm arrives. When evaluating rain water catchment systems, it’s important to factor in how large of a tank would be needed to meet a certain portion of the building’s water usage. Rain water catchment systems may not be as feasible in dry climates because a consistent amount of rainfall is needed year-round to make them viable in many cases. In regards to non-potable water supplied by a public agency, a concern that often arises is the higher salt and mineral content that is typically characteristic of this ‘purple pipe’ water. Further water use reduction can be found by reducing the water used for process water applications such as cooling towers. One thing to keep in mind with respect to LEED is that dishwashers and laundry machines, while located indoors, are NOT included in the credit calculations for Indoor Water Use Reduction. P Also, showers and kitchen sinks are only to be included as flow fixtures if they are located within the building and/or used by the building occupants. Process water strategies may earn points in the water efficiency section under LEED EBOM, but should be submitted under the Innovation in Design section for other LEED Rating Systems. This is a good segue to the next slide which shows the different points allocated to the Water Efficiency section.


Presenter

Presentation Notes

This slide shows the point breakdown within the Water Efficiency section for the current version of LEED NC, specifically looking at the number of points allocated to Indoor Water Use Reduction (Credit 3) and the percentage for each point threshold. The first item listed in the Water Efficiency section is the Water Efficiency Prerequisite which relates to indoor plumbing usage. Unless a project is able to achieve 20% savings, they will not be eligible for LEED regardless of how many other credits they are able to achieve. It’s important to note on this slide that the advantage of working with a new project is that the project team has the opportunity to select efficient fixtures from the beginning of the project. It’s more cost effective to specify efficient fixtures from the onset of a new project that to replace existing fixtures with more efficient ones in an existing building. The LEED Rating Systems addressing commercial buildings such as LEED CI, NC, CS, EBOM, etc. are all out of 110 possible points and the number of LEED points allocated to each credit are based on “Environmental Impact and Human Benefits”. Since each Rating System addresses different building types, the number of points allocated to Indoor Water Use Reduction may differ between Rating Systems. This is a good segue to the next slide


Presenter

Presentation Notes

Here, we discuss Water Efficiency Section as it relates to a different Rating System, LEED for Commercial Interiors. Since commercial interior / tenant improvement construction typically does not involve landscaping or building process water, the primary area of focus in LEED CI is indoor plumbing fixtures. This credit includes a Prerequisite as well and also includes the same percentage thresholds as LEED NC; however, the points allocated to each threshold are different. As you can see, 6 points are given for getting to a 30% reduction, 2 additional points are awarded for getting to 35% and 3 additional points are awarded for getting to 40%. This credit, like many others, has an Exemplary Performance threshold – meaning 1 additional ID point is awarded for reaching a threshold above and beyond the credit thresholds listed in this slide. In the case of LEED CI, NC and CS, the Exemplary Performance threshold for Indoor Water Efficiency is 45%. These percentage reductions are all based on a comparison with baseline flush and flow rates set by either the Energy Policy Act of 1992, the Uniform Plumbing Code or the International Plumbing Code. Here are the baselines for several common fixtures: Water Closets: 1.6 Gallons Per Flush Urinals: 1.0 Gallons Per Flush Bathroom Sinks: 2.2 Gallons Per Minute for Private Restrooms Bathroom Sinks: 0.5 Gallons Per Minute for Non-private Restrooms Showers: 2.5 Gallons Per Minute Kitchen Sinks: 2.2 Gallons Per Minute For a complete list of all fixtures and their corresponding baselines, please see the Reference Guide.


Presenter

Presentation Notes

With this slide, we briefly introduce the point breakdown within LEED EBOM specifically looking at the number of points allocated to Indoor Water Use Reduction under the “Additional Indoor Plumbing Fixture and Fitting Efficiency”. Even though this presentation is more geared towards new commercial buildings and spaces, it’s important to mention the fact that the EBOM system calculates the baseline differently than other LEED Rating Systems such as NC or CI. For fixtures replaced in 1993 or later, the baseline is 120% of the baseline flush and flow rates set by the standards referenced by LEED. For fixtures replaced before 1993, the baseline is 160% of the standards referenced by LEED. This is a good segue to subsequent slides that discuss the baseline flush and flow rates set by the Energy Policy Act of 1992 as well as the Uniform and International Plumbing code.


WE Prerequisite 1: Indoor Water Use Reduction Requirements Employ strategies that reduce indoor potable water usage by 20% below a calculated baseline.

Calculations are based on estimated occupant usage (Full Time Equivalent (FTE) occupancy plus average Transient Visitors) and should include only the following fixtures listed on the next slide.

Each 8 hour occupant has an FTE value of 1.0. To calculate the FTE of part time occupants, divide their hours per day by 8. Assumptions: Each person will use the restroom 3 times in one working day. The default male to female ratio is 1 to 1.

Presenter

Presentation Notes

All of the LEED Rating Systems now include a Prerequisite for Indoor Water Use reduction. This credit is a good example of a performance based credit as opposed to a prescriptive based credit. Points are awarded for getting to a certain percentage reduction in potable water usage and project teams maintain a certain level of flexibility with how they get there. This slide obviously does not include all of the details related to this credit, but it gives a good overview of how the credit is structured. Commercial buildings are required to get to at least a 20% reduction in potable water use for this credit when compared with a conventional baseline. The baseline flush and flow rates for this credit are set by the Energy Policy Act of 1992 as well as the Uniform and/or International Plumbing Code. For New Construction and Core & Shell projects, etc., this credit relates closely to Innovative Waste Water Technologies because any reduction in potable water used for restroom fixtures also helps reduce the water sent to the waste water treatment facility. This is an example of a credit that uses the Full Time Equivalency or FTE in the calculations. One FTE is generally referred to as equal to one person working full time or 8 hours/day. Part time employees are taken as fractions of FTEs. For example, one person working 4 hours per day is equal to ½ of an FTE (4 divided by 8 equals 1/2_). To give you practice, briefly solve this example: a project that has 20 employees that work 8 hours a day and 10 employees that work 4 hours a day would have an FTE of . .. . Answer is 25. “Transient Visitors” refer to people that visit the site, but that are not full or part time employees. In addition to FTE, average Transient Visitors should be factored into the calculations for Indoor Water Efficiency. For each FTE or transient visitor, LEED makes assumptions as to how many times in one working day that person will use different Indoor Water Fixtures. For example, LEED assumes each male FTE will use the restroom three times in one day – twice using the urinal and once using the toilet. The Reference Guide contains the full set of information regarding how many times each fixture is used per day by each FTE and transient visitor.


Baseline Baseline flush and flow rates are set by either the Energy Policy Act of 1992 and/or the International or Uniform Plumbing Code (IPC/UPC) according to the following table:

WE Prerequisite 1: Indoor Water Use Reduction

Fixture Baseline

Water closets 1.6 Gallons Per Flush

Urinals 1.0 Gallons Per Flush

Showerheads 2.5 Gallons Per Minute

Public lavatory faucets 0.5 Gallons Per Minute

Private lavatory faucets 2.2 Gallons Per Minute

Public metering lavatory faucets 0.25 Gallons Per Cycle

Kitchen and janitor sink faucets 2.2 Gallons Per Minute

Metering faucets 0.25 Gallons Per Cycle See the LEED Rating System for pressure (PSI) requirements for flow fixtures. The following fixtures and appliances are outside the scope of this credit: Steam Cookers, Dishwashers, Ice Makers, Clothes Washers.

Presenter

Presentation Notes

This chart shows the baseline flush and flow rates as discussed on the previous slide. Design flush and flow rates will vary based on which fixtures are specified. Many options are available. Regarding water closets, consumers typically have the choice between dual flush water closets and high efficiency flush water closets. Both save water and provide consumers choice. For people that do not like to use waterless urinals, ‘pint flush’ urinals are a popular choice and reduce water usage for urinals by 87.5% below the baseline. Notice the difference between “private” lavatory faucets and “public” lavatory faucets. Private lavatory faucets typically refer to faucets in hotel rooms, individual residences, hospital bed rooms and/or attached to a private office.


Requirements

Employ strategies that in aggregate use less water than the water use baseline calculated for the building. A 20% is required by the Prerequisite. Projects can earn points based on an additional reduction depending on the Rating System. LEED EBOM


LEED CI

LEED NC

Presenter

Presentation Notes

Now that we’ve covered information on the Water Efficiency Prerequisite, this slide serves to briefly introduce the Indoor Water Efficiency Credit which varies slightly by Rating System and uses the same calculation methodology as the Prerequisite. While project are required to comply with the 20 % reduction required by the Prerequisite, it is important to look for strategies that can achieve a 30% reduction or even higher in order to earn LEED points. Ultimately, for projects looking to maximize their environmental impact (and LEED point total) these additional indoor water use reductions are critical. As you can see from the first table, LEED EBOM includes 5 possible points for Indoor Water Efficiency – 1 point is awarded for an additional 10% savings, 2 for 15%, 3 points for 20%, 4 points for 25% and 5 points for 30%. Because of the point distribution for various credits, LEED CI offers more points for Indoor Water Efficiency than either NC or EBOM. 6 points are offered at 30%, 2 points at 35% and 3 points at 40%


Full-Time Equivalent (FTE) Information: • 80 Full-Time employees • 20 Part-time employees that work an average 4 hrs / day Design Fixtures • All restrooms have 1.28 Gallon Per Flush toilets • All male restrooms have low-flow (0.5 GPF) urinals • Low flow lavatories are 0.5 GPM, low-flow showers are 1.8 GPM and low flow kitchen sinks are 1.8 GPM Other Assumptions / Information • The building is operated 250 days/year • Assume the default male to female ratio • Assume all restrooms are public restrooms.


Presenter

Presentation Notes

Here is an example scenario taken from a LEED project I recently worked on. This slide provides all of the information you need to calculate the Indoor Water savings for LEED using the LEED Template. At this point, I’m going to toggle from the PowerPoint presentation to the LEED Template (see attachment) to briefly show you how the template works. (At this point in the presentation I will briefly display the WEp1 PDF Form on the screen while the Presentation is minimized)- As you can see on the template, there are areas for entering all of the relevant information such as FTE, days of operation, design flush and flow rates of various fixtures, etc. The FTE calculations can make things a bit more complicated when a project involves both residential FTE and commercial building occupants; however, this exercise will focus solely on commercial building occupants – full and part time employees. The Reference Guide walks through different examples using different occupant scenarios. Using the information provided in this slide and the WEp1 Template that you have been given access to (via email and via an FTP site), spend a few minutes completing the Indoor Water Usage template and see what you come up with for the overall percentage reduction.


Practice Problems 1 Gaining experience with the concepts by performing calculations by hand A new building has 20 Full Time Equivalent occupants, high- efficiency (1.28 GPF) toilets and half-gallon-flush urinals in all restrooms. How many gallons of additional potable water must be reduced per day in order to achieve a 50% reduction in potable water? (Assume the default gender ratio and exclude flow fixtures from calculations).


Presenter

Presentation Notes

LEED provides a credit calculator in the LEED form which simplifies the calculations. However, I think it’s important to understand exactly how the water efficiency calculations work in both practice and theory. For this reason, the first practice problem that participants do involves running part of the credit calculations by hand. This is a somewhat challenging exercise, but this instruction will help participants solve this problem each step of the way. Once participants understand how to run the credit calculations by hand, filling out the LEED form becomes much easier.



Presenter

Presentation Notes

Step 1 is to calculate the Baseline water usage. The FTE is 20 and we know that the default gender ratio is 1:1. 10 men are assumed to use the toilet once and the urinal twice, woman are assumed to use the toilet 3 times in one working day per the reference guide. Calculating the design water usage uses the same methodology – the difference is that the flush rates are more efficient. Once the baseline and design are calculated, step #3 calculates how many gallons per day we would need to reach in order to achieve the 50% reduction. Step 4 solves for the information we’re looking for – the additional gallons per day we would need to reduce by in order to achieve the 50% reduction. The instructor will spend plenty of time going over each step and answering all questions.


Practice Problem 2 Given the following project information, complete the “LEED WEp1 Credit Form” to the best of your ability. The credit form is a PDF attachment that was distributed prior to the course.

Full-Time Equivalent (FTE) Information: • 15 Full-Time employees • 10 Part-time employees that work an average 4 hrs / day

Design Fixtures • All restrooms have 1.28 Gallon Per Flush toilets • All male restrooms have low-flow (0.5 GPF) urinals • Low flow lavatories are 0.5 GPM, low-flow showers are 1.8 GPM and low flow kitchen sinks are 1.8 GPM

Other Assumptions / Information • The building is operated 250 days/year • Assume the default male to female ratio • Assume all restrooms are public restrooms.


Presenter

Presentation Notes

For this practice problem, the participants are given information about a project including FTE, design fixture flush and flow rates, and annual days of operation. As in any typical LEED project, participants must take this information and correctly enter it into the Indoor Water Efficiency LEED Form to determine the overall savings. As part of this exercise, participants will have access to a blank, editable LEED form that they can use to run the calculations. Participants will be given approximately 5 minutes to complete the assignment and the instructor will review the assignment afterwards while using his or her screen to show an example of a correctly completed credit form.


Practice Problem 3 Using the information given in Practice Problem 2, calculate the additional water savings from the design upgrades listed below (independently of each other) to determine which upgrade would yield the most savings?

a. Upgrading urinals to 1/8 gallon flush b. Upgrading water closets to the ultra-efficient 1.0 GPF


Presenter

Presentation Notes

complete the practice problem



Presenter

Presentation Notes

this is what the completed template will look like at 1/8 GPF



Presenter

Presentation Notes

this is what the completed template will look like at 1 GPF


Practice Problem #4 The following fixtures have been selected for the restrooms in a new commercial office building:

• Dual Flush Toilets (1.6 GPF Full Flush, 1.1 GPF Half Flush; weighted average flush of 1.35 GPF) • 0.5 GPM Bathroom Faucets • 1.0 GPM Kitchen Sinks • (No showers)

Assuming the restroom fixtures are considered “public”, which urinal represents the maximum flush rate that would help achieve a 30% reduction in Indoor Water Efficiency?

Waterless Urinal 1/8 GPF ¼ GPF ½ GPF


Presenter

Presentation Notes

This is the 4th and final practice problem. This assignment is representative of what occurs on LEED projects fairly often. The client or building have already decided on the flush and flow rates for some of the fixtures as shown. They’re left with a choice of several different possible flush rates for the urinals. Clogging of the pipes is a problem in certain buildings so they’d like to use the urinal with the highest gallon per flush that still achieves a 30% reduction in water usage. Participants will again use the LEED Credit calculator to determine which urinal will help them achieve the desired savings. This problem also provides participants an opportunity to figure out how to enter dual flush toilets into the credit form by taking the weighted average of the flushes. With a dual flush toilet, each woman would use the full flush 1 time and the half flush twice. Men would be assumed to use the full flush once, but not the half flush since they are assumed to use the urinal instead. Hence, there will be 2 full flushes and 2 half flushes for each Man/Woman combination in the FTE. Taking the weighted average of 1.6 and 1.1 gives a flush rate of 1.35 which can be used in the template.


Case Study: Post Montgomery Center

WATER CONSERVATION ANALYSIS (Based on 76 restrooms and 38 lunchrooms)

Measure Replaced Unit Number of

Fixtures Daily Water

Savings (gallons)

Annual Water Savings

(gallons) Annual Savings

($) Install 0.5 GPM aerators or faucet replacement with 0.5 GPM flow units

1 GPM 266 399 104,139 2,083

Toilet / Flusher replacement with 1.28 GPF unit

3 gpf 209 1,141 297,838 5,957

Toilet / Flusher replacement with 1.6 GPF unit

3 gpf 19 80 20,828 417

Urinal/ Flusher replacement with 1 pint flush unit (0.125 GPF)

2 gpf 80 300 78,300 1,566

501,104 $10,022


Presenter

Presentation Notes

To conclude the presentation, I’d like to briefly introduce a case study from a restroom fixture replacement project at a high rise building in San Francisco. The slide illustrates the measures that were implemented (design fixtures) as well as the existing fixtures that were replaced. Water savings in this case were compared with what was existing (as opposed to the baseline flush and flow rates set by a given standard). In this way, the building was able to estimate their return on investment.


Environmental Impact Analysis (100 cubic feet saves 5 lbs of CO2 & 8 KWH)

Annual Water Savings (gallons)

Annual Water Savings

(cubic feet)

Electricity Savings (KWH)

Pounds of CO2 Not

Generated 501,104 66,814 8,352 3,341

TOTAL SAVINGS 8,352 $3,341

Case Study: Post Montgomery Center


Presenter

Presentation Notes

This summarizes the fixture replacement case study on the previous slide and correlates the water savings with energy savings and CO2 reduction.


ROI Analysis for “Pint-Flush” Urinals

Results - $1,200 initial expense after rebate - 11,178 Gallons of water saved per year per fixture - 87.5% = percentage water reduction - $223.56 annual cost savings per fixture - Simple payback is 5.3 years


Presenter

Presentation Notes

Here is a simple case study regarding a urinal replacement in an existing building showing the initial replacement cost (after rebate), the gallons of water saved per year, the percentage water reduction, the annual cost savings per fixture based on average water rates in the area and finally, the simple payback in years. One of the reasons the payback is not sooner is because the cost of water is relatively cheap. Once the cost of water rises to reflect the limited supply, the return on investment will go up

CONCLUSION Photo credit: web.cityofwoodland.org

Presenter

Presentation Notes

Summation of course – what have we learned today?


Course Summary Now, the design professional will be able to:

1. Explain how the WE Indoor Water Use Reduction credits differ between various LEED Rating Systems and indicate system synergies.

2. Describe LEED Indoor Water Use Reduction credit calculation inputs, variables, assumptions & equations.

3. Calculate LEED WE Credits by hand, including the baseline and design case flush and flow rates to determine indoor water savings.

4. Complete the LEED WEp1 Credit Form through 4 practice problems utilizing a variety of fixture combinations.

CALCULATING INDOOR WATER USE REDUCTION FOR LEED

1 AIA HSW/SD CE Hour & 1 LEED Specific BD+C, ID+C or Green Assoc GBCI CE Hour

Alex Spilger, LEED AP BD+C, ID+C, EBOM [email protected] www.greenstepeducation.com

© GreenCE, Inc. 2012

AIA Course Number: ggs00a | GBCI Course ID: 0090008291


0090008291

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