Emily, the easiest way to accomplish this is to use the actual WEp1 Credit Form from LEED Online. If you don't have a registered project yet, you can download a sample WEp1 form from LEED Online as well.

Once you have the form, you can enter your Fixture Usage Group data (occupancy, fixtures installed pre/post 1993, etc.) and the information for the Baseline fixture case. After that, you can play around with the Installed case by entering different flow and flush rates to see how different retrofitting initiatives will play out at your facility and track the results of each scenario separately.

This is really the best way to do it because you're taking advantage of the USGBC-published calculation methodology within their own form. When you use a custom excel calculator, there's always a chance that your formulas will differ somehow. This way, you can be confident that the results are accurate.

Thanks. I find the online form to be even more complicated and obtuse than what I'm trying to build to aid our facilities staff in taking an inventory, but I suppose it still may be the best bet.

Emily,

If you're talking about the fixture inventory itself -- rather than the calculation of the baseline vs. installed cases -- then there is a template available through the 'Documentation Toolkit' tab for this credit (on this site).

Absolutely Udana. I don't believe the LEEDOnline template for WEp1 is currently set up to accomodate this calculation, but in principle the credit is about the amount of 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. used for fixture functions - using non-potable water to replace potable water is a step in the right direction. My thinking is that you would complete the fixture calculations in the normal methodology, then supplement your calculations with an additional submittal detailing the annual graywater1. Defined by the Uniform Plumbing Code (UPC) in its Appendix G, titled "Gray water Systems for Single-Family Dwellings," as "untreated household wastewater which has not come into contact with toilet waste. Grey water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs. It shall not include wastewater from kitchen sinks or dishwashers." 2. The International Plumbing Code (IPC) defines graywater in its Appendix C, titled "Graywater Recycling Systems," as "wastewater discharged from lavatories, bathtubs, showers, clothes washers, and laundry sinks." Some states and local authorities allow kitchen sink wastewater to be included in graywater. Other differences with the UPC and IPC definitions can probably be found in state and local codes. Project teams should comply with the graywater definitions as established by the authority having jurisdiction in their areas. collection volume (based on metering?) and the % reduction from the baseline resulting when that volume is subtracted from your WEp1 calculation. Alternately, if graywater provides 100% of your flushing water for toilets/urinals year-round, you could input those fixtures as 0 gal/flush and get the same result.

Hope that helps,

Dan

Thanks Dan. was thinking the same. :)

As long as the as-built drawing is dated after January 1, 1993, that seems like it should be an acceptable piece of documentation to verify that the prerequisite requirements are met.

Thanks for the reply Jason.

Another question: Is the cut-off Jan.1, 1993 or Jan. 1, 1994? The reference guide uses language such as "completed in 1993 or later" and "completed before 1993" implying that the important date is Jan. 1, 1993. However, on this site the language reads "in 1994 or later" and "pre-1994" implying that Jan. 1, 1994 is the cut-off. Which is correct?

David, the Reference Guide as published in 2009 has been updated by LEED addenda reflected in our language above. So it's the 1994 date.

David,

To add to Tristan's comment, your project only needs to adhere to the addendas which were dated prior to your registration date. You can search for this specific change on the USGBC site, here. Depending on when your project was registered it would be either 1993 or 1994.

If you're working on a EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. project for a K-12 school, you should actually list the students in the building as 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. (based on an 8-hour day). If this is in regards to higher education, where students are not in the building for large chunks of time, you can list them as transient visitors. In either case, you should be able to use enrollment records (or employee records), security logs, or simple interviews with building management to determine the number of occupants in either a school or office building.

If you are just trying to estimate the number of transient visitors to a project building, you can either use security logs or simply estimate the number of visitors based on interviews with building management or a reasonable ratio to regular building occupants. For example, if there are no security logs, but building management makes an educated guess to define the number of daily visitors as about 10% of the total regular building occupants, you can use that as guideline.

Thank you for the reply Jason. I am trying to certify a classroom building. So there are a TON of students going in and out of that building for lectures and discussions. I did take some time to go to the registrar, look up all the classes in the Classroom and Office building and pulled out all the class enrollment numbers for a Monday schedule and a Tuesday schedule, however; it is a ridiculous way to spend my time and there should be a more efficient way. I really appreciate the time you took to answer my question, it was helpful.

*if the project was built

That is correct - the EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. template even provides a compliance path specifically for buildings constructed in 1993 and beyond. That being said, in my experience, however, its not uncommon to find higher-flow fixtures even in buildings built in the 1990s. And two important exceptions that remain commonplace are faucets and showerheads - the 2.2gpm faucet remains far more common than 0.5 gpm faucets, and showerheads are all over the map these days. But the answer to your question is yes - the prereq can be earned automatically.

The expectation for the plan is indeed implementation, and I would caution the notion that other policies simply need to be written rather than implemented. For all prerequisite policies, LEED expects full implementation to the extent feasible. That doesn't necessarily mean a specific performance goal would be achieved, but it goes well beyond simply writing a plan and handing it over.

There are some pretty significant differences between the way that compliance was calculated in EB v2.0 and the current methodology for EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. v2009. I'm not quite sure that I understand why you want to use an EBOM credit form to document your NC project - have you tried using the WEp1 Credit Form provided in your LEED-NC scorecard in LEED Online? I'd strongly recommend this approach since LEED-NC uses yet another methodology that is different from both EB v2.0 and EBOM v2009. Specifically, the NC version of the credit calculates the baseline water consumption in a much more stringent way and you'll need to make sure you meet the NC requirements for your project rather than the more relaxed EBOM requirements.

Hi Michael,

Sounds like this would not count as a "plumbing rennovation", so you could still list those fixtures as pre-1993. Per p. 85 of the Reference Guide, my take is that a flushometerA device that utilizes pressure from the water supply system, rather than the force of gravity, to discharge water into the bowl of a toilet or urinal. It is designed to use less water than conventional flush toilets. change out is considered a minor retrofit, and doesn't trigger the more stringent baseline.

Your 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. example looks on target, and water fountains do not come into play for these calculations.

I would ask some questions like these...

Who is manufacturer of those closets?
Do they have some product sheets?
Do you count FTEs or actual number of people in your project?
Do you follow any local LEED rating system?

The manufacturer should be able to give you a flow rate for the fixture. (Is it difficult due to variable length of the spray or the age of the fixtures if they are existing?) I would then build a different fixture group for these toilets. As for use rates, these shouldn't vary from the regular toilet use rates. That figure is based on human needs. Anyone using a fixture should be counted and there are a lot of conversations on how to account for various different populations in the other WE forums so I won't repeat that conversation. The foot baths I would treat like process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making..

many thanks for the comments!

agree with the comment on use rate - this does make sense.

we do have the flow rates for the trigger spray, but finding it difficult to establish the length of the spray.

to be more specific and thinking out loud: the flow rate is 10l/minute (2.6gpm), all other WCs installed have flush rates of 3 - 6l/flush (0.8/1.6gpf). if we build a different fixture group for these toilets, we would, of course, need to include them under flow fixtures and could then possibly include them under the fixture family of a 'pre-rinse spray valve', in which case we could take a stab at average length of use?

Hi Suha,

In your situation, it sounds like the simplest approach would be to have enter two fixture groups: 1 for the renovated floors, and 1 for the non-renovated floors. You would only include as 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. the occupants that spend the majority of their days on that floors (so not cafeteria-only users). In reality, some of those folks would be using the restrooms on those floors, but there's not really a clean way to account for it.

Alternatively, you could use one fixture group and calculate the weighted average flush rate for the fixtures through the building.

Regarding your other question, I've worked on projects that can maybe sneak by the prerequisite by looking at aerators (0.5 gpm) on the lav faucets, and 1.6 or 1.8 gpm on any break room sinks. Usually, at least some of the toilets or urinals would need upgrading as well to hit the prerequisite, but it really depends on how bad the old fixtures are.

Paul,

I think you could justify inclusion of these folks if you can demonstrate a good rationale for doing so. But, that kind of special circumstance always opens the door for confusion during the review, and many times the % reduction doesn't change if you add or take away people because of how the calcs work (this is not always true, as in cases where the fixtures aren't uniform throughout the building).

Maybe test both scenarios of including and excluding those 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., and if it doesn't really change the results go ahead and keep them excluded for simplicity.

That's a tough one Kelly but the reviewers intent here is simply to ensure that the performance of the fixtures in the vacant space is not ignored in the calculation. They envision a situation where you have a discrete chunk of floor space that is empty, and that you can assign a virtual occupancy to that area by using the ASHRAE default rates. If vacancy fluctuated over the PP, I would be tempted to apply the occupancy levels from the beginning of the PP and calculate the remainder. But I'm not sure if I've quite answered your question. . .

The "Reduced Occupancy Guidance" document from the USGBC addresses this:

For floors or separate tenant spaces that are fully occupied or partially occupied during some portion of the performance period, use the normal procedures for this prerequisite. Assume any partial-year numbers apply on an annual basis as well unless circumstances justify an adjustment.

You can find the document at http://www.usgbc.org/ShowFile.aspx?DocumentID=6292.

My recommendation: If a portion of the building was occupied at the start of the performance period and now is not, then for WEp1 use the occupancy from when it was occupied. The same would be true for a space that was unoccupied and now became occupied during the performance period. The ASHRAE defaults only would apply to spaces that were completely vacant during the entire performance period.

I've got a similar situation, and I'm still confused about how to asisgn # of fixtures.
I have 190 fixtures (all replaced after 1994).
Occupied space has 355 people.
Unoccupied space assumes 145 people.

do I assign 190 fixtures to each group?
or split the total fixtures up proportionally?

thanks

Alyson - Can you assign fixtures based on their physical location? If the occupied space represents floors 1 & 2, and the unoccupied space floor 3, you can distribute fixtures accordingly. If not, proportionally would work as well.

Dan

Surenthira, flow restrictors are allowed to contribute to this credit, yes.

I just received the following comment after using the old policy: "Please provide a revised policy that requires economic assessment of conversion to high performance plumbing fixtures and fittings as part of any future indoor plumbing renovation. The policy must account for potential water supply and disposal cost savings and maintenance cost savings."

Would you say they're looking for some expansion of the items in section 6, or just the addition of potential maintenance costs?

1) If I had to use that estimate I'd probably equate a bank with service rather than retail, but frankly I would rather try to come up with my own estimate of foot traffic. The number of people entering tthe public space of a bank branch can vary widely and I'd feel more comfortable with a number you chased down than the Ref Guide multipliers. Any chance the bank has records of the # of teller transactions per day?

2) Only fixtures that differ from IPCInternational Plumbing Code/UPCUniform Plumbing Code - fixtures that are IPC/UPC compliant don't need to be documented.

Hope that helps,

Dan

Susan, I would say you've hit it on the head.

Susan, couldn't you simply use records from the property appraiser county or city database? Unless the plumbing system was upgraded or replaced after the initial construction, all you need to know is when the building was built. Does this help?

Hi,
Now Im confused, do we need the date of building was built or the plumbing fixtures was installed to comply on this requirement?

thanks,
susan

Susan, if you know when the plumbing fixture were installed then you need that date. if you don't know and you know that there has not been a major renovation of the plumbing, then you should be safe to use the date the building was built.

Hi Alexa,

Thanks for all your responses.
Will USGBC requires us for support documents if we choose either from this date (fixtures installed or building was built)?

Yes, and the same for all the other credits. Documentation is key internally and for this purpose it is helpful to stay organized.
The verbiage the ref guide says to provide is "Provide construction permits, substantial completion notices, contract excerpts, plumbing inspection or commissioning reports, or similar formal authentication of the date and scope of the comprehensive fixture and fitting upgrades."
Hope that helps and refer to LEED online and the ref guide for these required docs.
You're welcome!

Hi,

Im trying to use the sample active forms from LEED online V3 for Wep1 and WEc2 to check if we can meet the % requirement, seems like they didn't calculate?
If i have 2 water closet (WC) for each floor, do i need to input each, e.g. total of 4? How come they did not accept the Lavatory and faucets? Please help.

thanks,
susan

It sounds compliant to me Pablo - The intent of this aspect of the requirement is simply to ensure that future decisions about water fixtures are made with more complete information in hand. In most instances, fixtures are chosen based on appearance, function, and most of all, capital cost. By requiring economic analysis of more efficient fixtures, USGBC is simply trying to add 'long term water costs' and actual gallons of water saved to that decision matrix. If your assessment does this, it should be fine.

We are being asked to address "disposal cost savings" by the reviewer on our 2008 O&M project in our Economic Assessment policy. If we have already addressed reduced waste water generation - what would they be referring to?

Amy - sounds like a possible mix-up in terminology Amy. 'Disposal cost savings' sounds to me like money you won't be charged for sending water to the municipal sewage plant. I'm not really sure how that differs from waste water generation though - seems like different ways of referring to the same thing. Savings relating to this credit really only come from 3 places - spending less money buying water, spending less money paying to dispose of waste water (sewage), and any reduced labor costs thanks to the new fixtures. If you've provided those three things, you should be all set.

Complicated question Joanne - I'm struggling a bit to even understand the issues at hand. I think the key is that you should not feel limited by the template - what matters is accurately representing fixture water use in your building. That may mean creating separate Fixture Groups for the male and female populations of a given area. As to the question about the vacant space - no need to account for it separately if that space is served by a shared fixture location. What matters is how many people use a given fixture, how often, and how much water that fixture uses. Vacant space is only addressed separately if it contains dedicated fixtures.

I'm not sure if I helped at all or made things worse!

Dan

Joanne, it sounds like you've already done a fairly thorough job of conducting a water fixture inventory of the building. One option would be to have a single fixture usage group for the entire building and include weighted average flow and flush rates for each fixture type. This is allowable because all occupants in the building have access to all fixtures in the building. Think of it like a pool of fixtures and any occupant can use any fixture they wish at any given time.

If you'd like to try it this way, you would need to provide a detailed narrative (in addition to the WEp1 Credit Form) that summarizes the building fixtures and their installed flow/flush rates. Then you would need to map out the calculations you would use to come up with a weighted average flow or flush rate for each fixture type. Include a separate summary table that lists the weighted average flow/flush rate for each fixture type and make sure that this table matches the data you enter in the Flow Fixture Data and Flush Fixture Data tables on the Credit Form. Finally, make sure you include a manufacturer cut sheet for each fixture that has an installed rate that is higher or lower than UPCUniform Plumbing Code/IPCInternational Plumbing Code standards. This documentation will help support the data points that you use in your calculations to determine the weighted average flow and flush rates.

Throughout all of this, I'd recommend you maintain a 50/50 gender ratio for your fixture usage group and make sure that you account for potential occupancy of your vacant tenant space according to the Reduced Occupancy Guidelines.

Eddie, this credit is focused on overall water use, not peak use, so you would want to count all workers, not just those from the largest shift.

If we count 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. for all shifts, which I agree with, how do we account for bike rack quantities and other FTE driven requirements with a total non-simultaneous occupancy? 100 FTE for each of three shifts would be 300 FTE for the claculation of total water savings but we would not need 5% of 300 bike rack spaces when only 100 people will be in the facility during each of the individual shifts.

Correct, water use is from the total number of people flushing in a day, but bike racks should be based on peak occupancy during the largest shift. The PI Form 3 creates different occupancy numbers for peak and total that account for that and should link different 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. numbers to the different credit forms. See Table PIf3-2 and 3-3 for "Total peak users (FTE + peak transients)" and "Daily average project space users." There's a footnote indicating that the Total peak users can be adjusted for multiple shifts, but you need to explain that in the Special Circumstances.

Thus to answer Eddie's original question you'd count all employees for all shifts in a typical day in the FTE table PIf3-2 but reduce the "Total peak users (FTE + peak transients)" in Table PIf3-3 to reflect the busiest shift.

Incidentally, what can be confusing is how to count Transients (Students/ Visitors). The PI form 3-3 has a field for "Daily average," this should be the total number of transients that enter the facility in a typical day, which should be higher than the Peak number which is the high number of transients at any one time on a typical day, say during the lunch rush.

People often ask if transients should be counted separately or as part of the FTE numbers in Table 3-2 (the LEEDUser glossary says you can count them as either). Either way does work, but I think it's clearer to count transients differently from FTE.

For water usage, what matters is the fixture use assumptions that get assigned to FTEs and Transients. The "Total Daily Usage" number in the Flow and Flush Fixture tables of the WE credit forms is based on different number of daily uses assumed for an FTE person and a Transient person. (For example, a FTE person is expected to flush 3 times a day.) Those assumptions are listed in Table 1 of the "Water Use Reduction Additional Guidance" pdf document at:
http://www.usgbc.org/ShowFile.aspx?DocumentID=6493

Since they assume only one toilet flush for every two transients (0.5 per person), and no shower use, people may have different use patterns with their visitors, say in a gym or clinic. To account for that, the WE forms allow you to change the Total Daily Usage value in the tables, as footnote 2 in those forms indicates. Thus for a gym, you might expect 75% of your transients to shower (I'm just guessing), instead of none, so you'd increase the "Total Daily Uses" for the shower fixture row (you might have to add the row to the table.)

Hope that helps - sorry for the long response.

Thanks so much David. It's nice to have our assumptions confirmed. However My question is related to a few NC and CI projects where we have multiple shifts but EB was the only place I could find reference to a multiple shift 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. query. The NC and CI forms only seem to have a peak adjustment cell for Transients & retail customers and no modifier for a peak staff occupancy that would certainly be lower than a 2 or 3 shift workday that the bike rack credit would calculate from in lieu of the full FTE.

Anthony - This might explain it. I submitted the following to the LEEDOnline Feedback:

Issue:
When I go into LEEDOnline for a CI project for Table PIf3-3 (form version 3.0) I have an editable cell for the value of "Total peak users (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. + peak transients)*" that I can adjust if there's a lower peak FTE for shift work. There's an asterisk for that row indicating it can be modified for shift work: "*May be modified to account for shift work. If modified, provide a detailed explanation in the Special Circumstances section below."

But when I go into an NC project for the same table (also a form version 3.0) that same field is not editable and there's no asterisk or note. This would appear to be an error as the same situation could apply to an NC project. I'd propose that the same note and ability to edit that cell be added to the NC forms if this is indeed missing from the most current form.

Response:
The new version of the NC form (version 4.0) has a complex occupancy option for non-standard occupancy patterns such as shift work. If you would like to upgrade your form, please let us know via the Feedback Link. For more information on updates to the forms, please see the LEED Online v3 Form Fix Log.

We apologize for the inconvenience and thank you for your continued patience,

LEED Customer Service

I am not sure I understand the difficulty you are having. Can you clarify what the problem is that you need help with?

Thanks for your reply. The documentation tool kit has a general policy whereas we are unable to calculate potential water supply and disposal cost savings as well as maintenance cost savings. Please help me with a sample calculation sheet.

This kind of calculation is very project-specific. I'm afraid that I think you need to develop your own calculations for this.