NC 2009 WEp1: Water Use Reduction—20% Reduction

Hi Udana,
I'm not sure what you mean by residents use fixtures in the restaurant? But we model restaurants as no kitchen sinks, but do include any handwashing sinks as public lav faucets with a separate fixture group of staff useres. Private lav faucets in the rooms with a fixture group for your guests.

Hi Udana,
My recent response from the USGBC on this issue. They consider the existing Additional Water Reduction Guidance document which directs you to use a 1:2 ratio for commercial projects to apply for residential projects also for both males and females. "average volume based on a proportion of 2 half/1 full flush (3.33:1.67 or 3 half to 2 full if you prefer)".

Thanks Michelle. Good we can get to targeted savings with this approach :)

Your documentation needs to indicate the gender ratio will last for a long lenght of time - for example it cannot be something similar to 'this type of building has 75% female user ratio due the functions held inside" because the functions may change and there for the gender ratio may change.

We also have a similar situation for a park visitor center. The main users of the showers are not FTEs but park staff located in other buildings on the site. Is there a way to include shower users from these other locations in the V2009 template calculations?

we also have a similar situation for a fitness center. The main user of the showers are the visitors not 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. . I am not very sure but I am thinking using a separate group and show the group usage. ANY input or previous experiences ?

Susan, despite the fact that the showers are covered by EPAct, in this case, it sounds like the visitor shower uses would be considered 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. since the water use is part of the function of that space. You can claim savings by pursuing an Innovation credit for Process Water Use Reduction (see LEED Interpretations). Note that this credit would require that you account for all process water use in the project (washing machines, dishwashers, cooling towers, etc), not just the showers used by the visitors.

I never encountered this situation but I would try conservative approach. Hopefully this will achieve the reduction percentage you are looking for.

Yes an aerator can be used to reduce the water flow. The only catch is, if a lower flow aerator is manufactured for that specific faucet. I'd initially consult the faucet manufacturer. If that doesn't work, you can circumvent them and go to the aerator manufacturer, assuming that's a separate company. Neoperl (http://www.neoperl.com/default.aspx) is a large supplier to domestic faucet manufacturers and often times can tell you what aerators will fit what faucets.
Alternately, you could consider reducing the pressure of your whole system and naturally your flow will reduce.

Good news! Thank you!

Just a caution that reducing the pressure is not an option for LEED calculations - the LEED calculations are based on a baseline pressure. The pressure will affect the actual water savings, but LEED has been pretty consistent that the calcs need to have the same pressure.

To cut right to it, would a bathroom off of a private, 1-person or 2-person staff office in a hospital be considered a 'private' lav or a 'public' lav. The bathroom has no entrance/exit to a public or general population staff corridor.

Paul, the definitions you're looking for are on page 174 of the LEED Reference Guide:

"Facilities in residences and apartments, private bathrooms in hotels and hospitals, and restrooms in commercial establishments where the fixtures are intended for the use of a family or an individual are considered private or private-use facilities. All other facilities are considered public or public usePublic or public use applies to all buildings, structures, or uses that are not defined as private or private use.. If the classification for public or private usePrivate use applies to plumbing fixtures in residences, apartments, and dormitories, to private (non-public) bathrooms in transient lodging facilities (hotels and motels), and to private bathrooms in hospitals and nursing facilities. is unclear, default to public-use flow rates in performing the calculations associated with this credit."

We have listed inpatients and hotel guests as residential when calculating 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.. But should we go for the private facilities when possible in the water calculations? Since it is private when they are at the hospital or hotel, but not residents.

If your inpatients are in single/private rooms, then by all means use the private designations. I believe that the hotel guidelines also allow the use of the private designation. Do a quick search on the USGBC site for CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide/LIDs. I know it is there.

Thank you, I will look for a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide.
One thing I recognized when elaborating with the different fixture families is that the total number of usage per day changes and sometimes also the baseline. That gives a big impact on the calculations. If I list the guests as FTEs and want to use the private fixtures, I have to change the default usage values (otherwise 0). Which indicates that it is the residential groups I should use?
In my opinion the calculations don’t give a correct picture of the actual water usage at all it is just elaborating with figures.

I modify the 'Resident' use patterns in both baseline and design case scenarios to reflect actual use to the greatest extent possible. Then it is backed up with the narrative. For example, my inpatients are 'Residents' but do not use a kitchen sink at all. We zero out the kitchen sink use in both places. It seems to be working....

Great, i will also follow that path.
But did you use private or residential fixture groups for the inpatients.
Thanks for giving advice!

It sounds like you may be submitting under LEED-CI. If that's the case, you can ignore fixtures not in the tenant space.

Thank you Amy! You are correct - it is a CI submittal. With your comment we were able to confirm with our support team we do not need to include the building fixtures. A quick technical question for you, however. We left the fixture table in the form blank and it is stating we have not completed the required documentation for this Pre-req. We 'declared special circumstances' and uploaded the project drawings to show no fixtures and it is still showing we have not met the documentation criteria. Do we submit anyways and assume the reviewer will understand?

Again, thank you for your help!

I guess you need to seek gbci to upgrade WEP1 form from Version 3 to Version 4. In the latest form, we could select 4 different scenario.
a. tenant space fixtures only
b. outside fixture only
c. both - outside fixture included
d. both - outside fixture excluded.

Thank you Jason. I'm not able to find anything in the form that gives us the option to chose those scenarios. I'll ask the gbci how we can get them to upgrade the form.

I’m working with LEED projects in Sweden and face the same problem. To be able to meet the total reduction of 20% we compensate with very low flow toilets compared to the baseline (0,7gpm).

If you are interested in credit 3, I don’t have a good answer; I don’t understand how you can have such a low flow, even if you mix the water with air. You get a much better value in the calculations if you install faucets whit sensors, but those are more expensive.

Alternatively look for taps that have a limited flow when you put it on but don’t hold it. If you need to have a bigger flow you must hold the handle up (if you need to fill a can or something).

Veronika, looks like we found 2 Liter per minute faucets from the brand Presto....

I will check that out.

The architect in this project now proposes a faucet with a sensor that only turns on when your hands are under the faucet. How do you calculate the gallons per cycle on a faucet like this?

I saw some low flush HEP options by Zurn for K-12 1.28gpf http://www.zurn.com/pages/catalog.asp?ProductGroupID=147&OperationID=19

The current default time for showers is 300 seconds (only 5 min). I would imagine that you would have to show your own alternative compliance path for your metered shower fixture. You could use the same logic that is used for metered public lav fixtures and convert the usage to gallons per cycle, ( x gpm * sec cycle)/ 60 sec. The baseline would be what LEED already uses (2.5gpm *300sec)/ 60sec =12.5 gallons per cycle. You then compare it to your design case where you would reduce the cycle, or the gpm. However, the bigger question would be if a metered shower would really even reduce water. The 300 second default is based on behavior patterns. Even if you were to reduce the cycle to 200 seconds, wouldn't someone still need at least 5 min to shower? In reality, they might just set the cycle off again after 200 seconds to finish their shower and then you have someone showering for 400 seconds in reality. If it is the shower head itself that you are reducing, you are better off going with the straight shower calculation anyway with out the metering component.

Great advise Seema,
We only have cycles of 30 sec (standard) and approximately 5 cycles per person (standard). So if we do the calculations the way you suggested:

(2,1 gpm * 30sec * 5)/60 sec = 5,25 gpc.
(x gpm * 300sec)/60 = 5,25 gpc
X = 1,05 gpm using the default 300 sec value.

The benefit with the metering is that the person taking the shower is not letting the water while shampooing and therefore a shorter time and less water.

Do these calculations seem reasonable?
Thanks, Veronika

Hi Veronika,

The calculation looks logical. However, how are you deriving that each person will use an average of 5 cycles? Since you are deviating from LEED's prescribed calculation method, the reviewers will no doubt ask for as much back up as possible to support your claim of 5 cycles and why you are not using 300 seconds or 10 cycles to = 300 seconds. If you do decide to go this route, I would also suggest writing a full narrative showing how you used the same calculation logic as the metered public lav. Best, Seema

Good, we are following our design praxis. But I agree with you that I must find this in written for proper backup documentation. Otherwise they will probably not accept it.
Thanks again Seema for your advices. /Veronika

Rand
I apologize that I do not have any answer for you but wanted to chime in and second what you have said. We have just received the same review comment. I agree as well that the review team's language was significantly insufficient in assisting us address this error. They referred us tthe same document but it says nothing in regards to how address this issue. If I come across something that is of assistance to us I will send it your way.

Can you logically assign a user group to the single bathroom and then break it down? Let's say only 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. will have access to the single room and they are located to one side of a building. You could determine the number of FTE likely to use the single room (by travel distance) and 50% of that figure will not be using urinals. This way your visitors/transients groups are all using the core toilets. You could either add a fixture group or assign the urinals a percentage of use based on all your occupancy figures.

Rand,

I'm not sure I agree with your assumption that the single toilet rooms will be used infrequently, unless they are private. If it's possible at this point in design I'd reccomend adding urinals to the restrooms in question if these points are paramount to your project.

That may seem extreme, but I think it will be difficult to make an arguement here. Everyone who uses the private restrooms will be flushing the toilet because they do not have the option to use a urinal. 

We have successfully documented this under LEED 2.2 by counting fixtures - so if we have 10 fixtures in public men's restrooms (7 stalls and 3 urinals), and 2 unisex toilet rooms, we've assumed an even distribution of 12 uses, so the percentage without access to urinals is 2/12. I could not determine a good way to justify more or less frequent use of any one toilet room over another. It may not be perfect, but it is close. I often try to encourage adding urinals as Emily recommends, but it often not feasible.

Unfortunately it seems that the reviewer missed the following statement in the additional guidance document they are referencing, "projects are still allowed to use on-site alternative sources of water to achieve water use reduction through an alternative compliance path."

You may need to adjust your calculation methodology as you still need to show fixture efficiency, but you should be able to subtract the non-potable supply from your calculated consumption to show overall reduction per the methodology outlined in that same document.

However, I wonder if there is a misunderstanding based on the terminology being used. You are claiming municipally supplied 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. and they refer to municipally supplied greywater, neither of which are standard. Potable v. non-potable should be all that matters in this case, but I suggest clarifying the terminology as well.

Good luck!

LEED's policy usually is that if you take credit for using something on one credit (ie SSc4.2) you need to carry that through on all credits.

Also for CI, LEED requires that you include all fixtures that the building occupants will use. For instance, if the building doesn't have any toilets or urinals and people go next door to use the restroom then you need to include those fixtures in your calc. I would guess that carries over to NC.

Do the showers precludes you from getting WEp1 or your desired points on WEc3?

If you are looking to achieve greater than 20% water use reduction (and achieving credits through WEc3), I would think you need to include the showers and any fixtures that the occupants use as part of your calculations. If you are only going for the prerequisite, I think you could be ok with excluding them.

USGBC provided an update in the ID&C addenda that projects pursuing WEp1 only need to consider fixtures or fixture fittings within their tenant space. Any fixtures not within the tenant space can be exempt. Yet, if the project team is pursuing water use reduction beyond the prerequisite threshold, they need to include all water use fixtures used by the occupants in the calculations. I would think this would be the case for NC projects as well, but suggest checking with USGBC / GBCI to confirm.

Thanks to the two of you.

Our first goal is to achieve the baseline.
But building one, the one without showers, have a hard time to reach the baseline (working on it). But if we would include showers it would help us meet the baseline. So it would be beneficial to us to include showers from another building. But I think this is the appropriate approach according to yours answers.
Building two, the one with showers, we reach above 30 %, (excluded 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. from building one). The energy and data share, required in PIf1 might be misleading, since the figures will not be correct when people from building two also use water.

/Veronika

I am curious about this - I have not seen anywhere that project teams need to include outside showers for SSc4.2. I think there is a distinction between the CI guidance which I think is aimed at tenant spaces with toilet cores outside the tenant space and NC projects which may have showers outside the project scope. Or am I overthinking this?

Thanks Tristan.

Q1) My assumption has always been that for some occupancies it is easier to get 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. data broken out that way. It is a way for the design team to fill out the form using data provided by the owner.
Q2) I think you may be able to make the case that the students should be calculated differently than normal.
Gender) I've gone down the road with the GBCI on uneven gender ratios and they have consistently insisted that unless the occupancy is limited to one gender that the split is 50-50. For example, you can not tell them that 70% of the nurses are female and use a 70-30 split for staff because staffing can change over time.

It sounds like you have a really good handle on the building occupancy for your project. I would calculate credits based on a fair but conservative approach and provide my back up as an attachment. This has been working for us.

Alicia, you can conduct actual measurement of use. See our guidance on EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. water credits for some additional input on this.

Sonrisa, typically the project’s LEED registration date determines which Addenda, LEED Interpretations and formal guidance documents are applicable to the project. In this case, however, I would recommend following the Water Use Reduction Additional Guidance (updated July 14, 2011) and claim no water savings for the blow-out fixtures. This is the conservative approach and will likely result in a more straightforward review of WEp1. That being said, if you want to provide the GBCI with a narrative stating that your project is not subject to the guidance in the document because it was registered prior to its release date, you’re welcome to do so. The narrative should be submitted along with your WEp1 documentation in LEED Online.

It can be difficult to keep up with the constant changes to the various LEED rating systems. My recommendation would be to occasionally visit the rating system pages on the USGBC website to ensure that you remain in the loop. Here is the page for the New Construction (NC) rating system: http://www.usgbc.org/DisplayPage.aspx?CMSPageID=220

Sonrise,
we also have the same review comment regarding the blow out fixture. our project was registered prior Version 3 of Water Use Reduction Guidance was out. somehow the reviewer want us to change the installed blow out gpf to follow as 3.5gpf as baseline. we will lose 3 point out from this. we also writing a narrative mentioning that our project follow the previous revision prior the new one was out.