NC-2009 WEc1: Water Efficient Landscaping

  • NC CS Schools WEc1 Credit Req's Diagram
  • Can be either simple or complex—it's up to you

    You can earn this credit simply by eliminating turf grass, planting native and adaptive species, and not installing an irrigation system. If those measures go too far for your project, you can still achieve the credit as long as you have some flexibility with plant species selection, and irrigation system design and controls. You may need a landscape designer to identify local or adaptive plant species that require little irrigation, to design water-efficient irrigation systems, to address the potential use of non-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., and to reduce irrigation needs through zoning, grouping, and grading of the landscape.

    If you install irrigation

    If you do install irrigation, you must perform calculations to show the savings of the project design versus a baseline. Usually done by the landscape architect or architect, these calculations determine the percent reduction of total water applied and total potable water applied. Projects with landscaping on less than 5% of their site area cannot earn points here, so consider planters or small gardens to meet that threshold.

    FAQs for WEc1

    Can non-potable well water that is used for irrigation contribute to potable water reduction?

    No, non-potable groundwater used for irrigation (other than nuisance groundwater, i.e. water pumped away from a foundation) is considered a potential potable source and would not count towards earning this credit. GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). has upheld this rule even in cases where the local groundwater has mineral or other content that requires treatment before it can be potable.

    Can surface water, such as water from an irrigation ditch or a local creek, be used as nonpotable water?

    No. This approach has been rejected by LEED reviewers, who state that these are potential sources of potable water and their use does not meet the credit intent. The LEED Reference Guide makes reference to groundwater in specifically allowing use of nuisance water that needs to be pumped away from the building—but other groundwater is not mentioned as compliant.

    Is the area of the baseline case the same as the design case?

    The baseline and design cases are the same, and they are based on the total landscaped area in the design case.

    What is the minimum required irrigated area that will achieve the credit?

    There is no minimum required irrigated area to achieve the credit.  Projects without vegetation on the grounds must have vegetated areas such as courtyards, planters, or vegetated roofs equal to at least 5% of the total site area to pursue the credit. Projects with no landscaping are ineligible for the credit.

    Does existing landscaping have to be included in the calculations?

    Yes, all landscaping (existing and new) must be included in the documentation.

    Do vegetated roofs count in the calculation?

    Yes.

    Do interior planters count in the calculation?

    No. LEED defines the scope of the credit as landscaping outside of the building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint..

    Does installing artificial turf, pavers, or hardscape in place of landscape plantings improve your chances of getting the credit?

    Although this may contribute to reducing irrigation demand, this does not help with achieving the credit, as landscaped area in both the baseline and design case has to be the same (see the LEED Reference Guide for acceptable methods to earn the credit, and LEED Interpretations #6039 and #731—which have not been applied officially to LEED 2009). Although decreasing vegetated space may be a sensible option for some projects, it is not allowed to contribute to this credit. It would not match the intent of this and other credits for LEED to include an incentive to reduce vegetated area.

    How long can a temporary irrigation system for plants to be established remain on site and have the project still be able to achieve the credit?

    According to a LEED Reference Guide addendum from 7/19/2010, the time period has been increased from 12 months to 18 months.

    How is "temporary" irrigation system defined? What do I have to do to show that a system is temporary?

    LEED does not distinguish what characteristics make an irrigation system "temporary." However, teams have had success by installing irrigation systems with plans to disable them in some way, such as removing sprinkler heads, cutting up pipe, or causing some other severe, if not unalterable, damage to the system.

    We are using non-potable water for irrigation. For drought conditions, can we hook up to a potable water source for backup and still earn this credit?

    Yes. According to LEED Interpretation #998, "The approach of designing rainwater storage for a 'normal' rainfall year and providing potable water as backup is acceptable."

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Eliminating turf grass, planting native and adaptive species, and not installing an irrigation system is the simplest and cheapest way to achieve this credit. It will also have several additional environmental and financial benefits not necessarily recognized by LEED, such as reducing mowing costs, energy use, emissions, pesticide and fertilizer needs, and maintenance. Start by evaluating this option, taking into account the owner’s expectations, the climate, and site conditions.


  • Native plantsLawn as the default landscape planting doesn't make sense in dry climates, where its lushness can only be maintained at the cost of frequent watering. Xeriscaping such as shown here, using native and drought-resistant plants, is a better choice. Las Vegas Valley Water DistrictEvaluate the project’s landscaping needs and develop water savings goals. Consider opportunities to use native or adapted vegetationAdapted (or introduced) plants reliably grow well in a given habitat with minimal winter protection, pest control, fertilization, or irrigation once their root systems are established. Adapted plants are considered low maintenance and not invasive. to reduce irrigation needs. Look for all water sources on the site, such as stormwater, graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area., treated wastewater, and note opportunities for using that water for irrigation. Include water savings goals in the Owner’s Project Requirements (OPROwner's project requirements (OPR) is a written document that details the ideas, concepts, and criteria that are determined by the owner to be important to the success of the project.) for EAp1: Fundamental Commissioning.


  • If your landscaping is limited to planters and small gardens, calculate vegetated area as a percentage of the total site area (including building footprint). If the planter and garden area is at least 5% of the total site, you’re eligible for both credit options. If you’re just below that amount, you're ineligible for this credit. Consider adding planters as an amenity for the building and a way to earn the credit.


  • Using alternative water sources for irrigation may add costs compared with conventional irrigation. For example, a rainwater cistern will be an added cost, and space must be found for it. However, this may lead to cost reductions in other areas, such as reduced stormwater retention infrastructure, or lower water and sewer costs.

Schematic Design

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  • Research native or drought-tolerant plants and efficient irrigation systems and controls. Check for local incentives for efficient systems and controls.


  • Evaluate the potential for nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. sources, including rainwater reuse and graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. reuse. If non-potable water use seems feasible for your project evaluate the water demand for your landscape and the quantity of water reuse available to your project. Calculations, usually done by the landscape architect, have to account for annual rainfall on a monthly basis for the project location. Rainwater, which may need basic filtration but not usually additional treatment, can be piped directly to plantings to reduce the need for potable irrigation water. Evaluate the potential for graywater. Research graywater or rainwater regulations, and local incentives. Check with local authorities on acceptable rainwater and graywater capture, collection, and reuse methods. Local codes may place limits on some uses of alternative water supplies. Develop a water budget, both project-wide and for landscape irrigation.


  • Work with the whole project team to evaluate synergies and tradeoffs with other LEED credits or green building strategies. These may include using rain gardens for stormwater infiltration, trees for shading the building and hardscapes for cooling-load reduction, porous surfaces, soil selection encouraging infiltration, windbreaks, water reuse, rainwater capture and acoustical barriers.


  • The following water sources count as reused for credit purposes: graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. (lavatory, sink and shower water), harvested rainwater (cistern, underground, or pond), nuisance water (water that must be pumped away from the building), treated wastewater, air-conditioner condensate, reverse-osmosis reject, and sump-pump water. All well water is counted as potable for credit purposes.


  • Starting the LEED calculations early, along with early completion of a compliant landscape design can avoid costly redesign due to non-compliance.


  • For Option 2: No Potable Water Use or No Irrigation, projects have to achieve a 50% reduction in total water applied in addition to eliminating irrigating with potable water. That is, even if a project uses non-potable water for irrigation, it must also reduce the total water use for irrigation by 50%. To use non-potable water to pursue Option 2, projects must provide a detailed narrative on the actual source and available quantity of the non-potable water as well as the anticipated schedule for implementation of the non-potable system.


  • You can avoid submitting calculations for credit compliance by not using permanent irrigation. In this case, no permanent irrigation system can be installed, even with the intent to turn it off. Irrigation for plant establishment, allowable for one year, must be manual, or through temporary, above-grade systems. Using hose bibs to water when plants are being established and during drought conditions is allowed as “temporary irrigation.”


  • Look for local incentives for sub-grade irrigation, efficient irrigation, irrigation controls, and/or irrigation sub-metering. For example, one city provides up to $7,000 per acre-foot of water saved, and another program provided rebates up to $1,000 per acre for weather-based irrigation controls. Some municipalities even support “cash for grass” programs that provide rebates for the replacement of turf and with native plantings. For example, one pilot program provides $1.00 per square foot of replaced turf grass.

Design Development

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  • Evaluate a number of scenarios to achieve the credit. Look for options that work best for the design, and see if there are any trade-offs or overlaps with other LEED credits.


  • Drip irrigation   If irrigation is necessary, drip irrigation is a water-efficient way to deliver it where it is needed, with minimal evaporative losses. City of San Luis Obisbo Utilities DepartmentDesign landscape and irrigation systems to maximize native and adapted species, use efficient irrigation technology, and reuse water where possible. Evaluate the different irrigation technologies for their efficiency and suitability to the project. These include subsurface, bubbler, drip, and rotor sprinkler. Installing weather controls or soil moisture sensors can greatly reduce unnecessary irrigation. Consider directing rainwater to planting beds to reduce the need for potable irrigation water.


  • Detailed calculations to demonstrate irrigation efficiency will be required from the landscape architect. The study “Performance and Water Conservation Potential of Multi-Stream, Multi-Trajectory Rotating Sprinklers for Landscape Irrigation” (see Resources) provides expected water conservation percentages derived from measured data. Efficiency ratings provided by manufacturers for irrigation components and controls can be used for calculations, but most manufacturers do not provide this data, so you’ll need additional calculations.


  • Drip irrigation systemUse of drip irrigation helps to conserve water. BuildingGreen ImageThe design cost of a drip irrigation system is generally comparable to a standard system. However, installation might be more expensive for drip irrigation, particularly as plant density increases.


  • The landscape architect calculates the potential for rainwater reuse and corresponding cistern sizes to accommodate landscape and other rainwater reuse applications. Calculations must account for annual rainfall of the project location.


  • There are fewer codes and associated costs for collecting and using rainwater for irrigation than for interior water reuse. Harvested rainwater can often be reused for irrigation purposes with minimal treatment, although filtration is usually needed.


  • The mechanical engineer calculates the potential for graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. reuse and applicable treatment methods.


  • Perform LEED calculations to evaluate compliance. Only “softscape” areas are included in calculations. Projects that replace landscape irrigation with hardscape to reduce irrigation needs cannot count this area in their calculations.Use the calculator provided in the LEED Online credit form to evaluate compliance.


  • The landscape architect develops a baseline outdoor-water-use calculation based on mid-summer (July) and compares that to a calculation for the planned project design case water use (also for July). The difference is the percent reduction and identifies credit achievement. Factors included in the calculations are: plant species, density, microclimate, evapotranspiration rate, irrigation efficiency,, and non-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. use, and controller efficiency (gains from controller efficiency cannot exceed 30% in July). The local project baseline case is a subjective calculation that will vary by city and is based on standard practice in that region. The landscape design case is created by setting the irrigation variables to values representative of the actual designed landscape plan. The landscape water efficiency boundary used must be the same project boundary used for all other LEED credits. (See the documentation toolkit  for more information.)

Construction Documents

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  • The landscape architect runs final outdoor water use calculations for the project’s design case annual water usage. These calculations should confirm that the landscape water reduction goals are met. If the goals are not met, adjust the landscape and irrigation design as needed.


  • The landscape architect provides LEED documentation for submittal to LEED Online.

    • Provide landscape drawings.
    • If installing irrigation, provide area, species factor, density factor, microclimate factor, project evapotranspiration rate, and irrigation type for reach landscape type. You must provide the information for both baseline and design case.
    • If using non-potable water, provide information on source, and other documents that support proof of non-potable water use.
    • If no irrigation is installed, the landcape architect or architect must sign the LEED Online credit form stating that permanent irrigation will be removed after plant establishment.
    • If no irrigation is installed, write a narrative describing the landscape used.

Construction

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  • The commissioning agent commissions irrigation and water reuse systems to ensure they operate as designed.

Operations & Maintenance

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  • Create a maintenance plan to ensure ongoing, as-designed performance of irrigation systems and equipment. Doing so will also contribute to LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. credit compliance. Along with the maintenance plan, provide product manuals for irrigation systems including weather and moisture controls to maintenance personnel, and discuss irrigation and planting maintenance needs. When operational, verify that the sprinkler system is not spraying the building, to avoid water waste, mold and termite damage. Also avoid wasting water spraying on other hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. surfaces like roads and sidewalks.


  • Minimize irrigation frequency in an effort to conserve water. Apply irrigation at the lowest rate required to keep plants healthy. New plants may need to be irrigated more, in order to establish them.  Change irrigation schedules on a regular basis to adjust for seasonal variations in watering needs, including turning them off in the fall. Use an irrigation system that is tied directly to weather forecasts, or manually program irrigation clocks weekly or more often, based on projected rainfall and weather patterns.


  • Incorporating mulch and using mulching mowers will help keep moisture in the soil, and reduce irrigation needs.  Adding compost to the soil will help maintain plant health over time and aid in moisture retention.


  • Creating an Integrated Pest ManagementIntegrated pest management (IPM) is the coordinated use of knowledge about pests, the environment, and pest prevention and control methods to minimize pest infestation and damage by the most economical means while minimizing hazards to people, property, and the environment. plan will offer environmental and health benefits, while contributing to the ongoing attractiveness of the landscape. Doing so will also contribute to LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. credit compliance.


  • Installing a sub-metering system for irrigation water can help operators monitor water usage and detect problems early on. Doing so will also contribute LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. credit compliance.


  • The cost of maintenance will vary depending on the strategy employed. For example, subsurface or drip irrigationDrip irrigation delivers water at low pressure through buried mains and submains. From the submains, water is distributed to the soil through a network of perforated tubes or emitters. Drip irrigation is a high-efficiency type of microirrigation. systems can be more difficult to maintain, because malfunctions are more hidden.

  • USGBC

    Excerpted from LEED 2009 for New Construction and Major Renovations

    WE Credit 1: Water efficient landscaping

    2–4 Points

    Intent

    To limit or eliminate the use 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. or other natural surface or subsurface water resources available on or near the project site for landscape irrigation.

    Requirements

    OPTION 1: Reduce by 50% (2 points)

    Reduce 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. consumption for irrigation by 50% from a calculated midsummer baseline case or using the month with the highest irrigation demand.

    Reductions must be attributed to any combination of the following items:

    • Plant species, density and microclimate factorMicroclimate factor (kmc) is a constant used in calculating the landscape coefficient. It adjusts the evapotranspiration rate to reflect the climate of the immediate area.
    • Irrigation efficiency
    • Use of captured rainwater
    • Use of recycled wastewater
    • Use of water treated and conveyed by a public agency specifically for nonpotable uses

    Groundwater seepage that is pumped away from the immediate vicinity of building slabs and foundations may be used for landscape irrigation to meet the intent of this credit. However, the project team must demonstrate that doing so does not affect site stormwater management systems.

    OR

    Option 2: No potable water use or irrigation1 (4 points)

    Meet the requirements for Option 1.

    AND

    PATH 1

    Use only captured rainwater, recycled wastewater, recycled graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. or water treated and conveyed by a public agency specifically for nonpotable uses for irrigation.

    OR

    PATH 2

    Install landscaping that does not require permanent irrigation systems. Temporary irrigation systems used for plant establishment are allowed only if removed within a period not to exceed 18 months of installation.

    Potential Technologies & Strategies

    Perform a soil/climate analysis to determine appropriate plant material and design the landscape with native or adapted plants to reduce or eliminate irrigation requirements. Where irrigation is required, use high-efficiency equipment and/or climate-based controllers.

    Additionally the credit can be met when landscape irrigation is provided by raw water (excluding naturally occurring surface bodies of water, streams, or rivers, and ground water) that would otherwise be treated specifically for nonpotable uses. Only ponds designed solely for the purposes of stormwater retention or detention can be used for this credit.

Organizations

American Rainwater Catchment Systems Association

ARCSA was founded to promote rainwater catchment systems in the United States.  The ARCSA website provides regional resources, publications, suppliers, and membership information. 


Center for Irrigation Technology

CIT is an independent research and testing facility that provides information to designers, manufacturers, and users of irrigation equipment.


Irrigation Association

This nonprofit organization focuses on promoting products that efficiently use water in irrigation applications.

Articles

American Water Works Association, Water Wiser: The Water Efficiency Clearinghouse

The clearinghouse includes articles, reference materials, and papers on all forms of water efficiency.

Web Tools

National Oceanic and Atmospheric Administration, National Climatic Data Center

The NCDC site is useful for researching local climate information such as data for rainwater harvesting calculations, and it also includes links to state climate offices.


World Water and Climate Atlas

Enter your project latitude and longitude—easily taken from Google Earth—and you will get the ETo for pretty much anywhere on earth. A note of caution: spot checking reveals that data may not be reliable in all locations. Make sure that data such as precipitation and temperatures checks out before using the ETo values proposed by the model.

Software Tools

Rain Bird® ET Manager™

This free software provides sufficient local evapotranspiration data for the United States and Canada.  Access data from the closest or most climate-appropriate location. 

Technical Guides

Texas Water Development Board website

This website provides data from the state of Texas regarding water resources and services such as groundwater mapping and water availability modeling.  The site also provides brochures on indoor and outdoor water efficiency strategies.


Performance and Water Conservation Potential of Multi-Stream, Multi-Trajectory Rotating Sprinklers for Landscape Irrigation

This study provides expected water conservation percentages derived from measured data, which can be used to support water efficiency calculations for this credit.

Publications

U.S. EPA, Water Efficient Landscaping: Prevening Pollution and Using Resources Wisely

This manual provides information about reducing water consumption through creative landscaping techniques.

Landscape Plan and Narrative

All Options

Use a site plan and narrative to approach and document credit compliance, like these examples from the Denver School of Science and Technology Landscape Design.

Narrative – Water Use Reduction

Option 1

Use a narrative like this to demonstrate a 50% reduction in 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. use.

Narrative – No Water Use

Option 2

Use a narrative like one of these to demonstrate no 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. use for irrigation, or no irrigation.

LEED Online Forms: NC-2009 WE

Sample LEED Online forms for all rating systems and versions are available on the USGBC website.

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

446 Comments

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Joyce Kelly Consultant Architectural Fusion
Jun 22 2016
LEEDuser Member
255 Thumbs Up

"Provide calculations to confirm the quantity......"

Project Location: United States

We are having difficulty figuring out what the following review comment means.
"Provide calculations to confirm the quantity of nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. used for irrigation (52,148.46 gallons in July.) The number they provided in parentheses is from the table in our template and is the result of the standard calculation. What other calculation could they be referring to? We are confident we have achieved this credit by using only purple pipe reclaimed water and rainwater which is collected from condensate, Winter rains and Summer monsoons and is stored in a 52,000 gallon tank.
Perhaps it means they want calculations illustrating that nonpotable water systems support the quantities entered in the table. Any std. means to do that?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M; CxA: Green Rater in Training, Revitaliza Consultores Jun 22 2016 Guest 1504 Thumbs Up

Yes, you are expected to demonstrate with calculations the figure you entered in the cell "Nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. used (gal)".

I think you have to investigate available purple pipe reclaimed water and rainwater during July.

I hope this helps.

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William Weaver LEED Fellow, JLL Jun 23 2016 LEEDuser Member 1998 Thumbs Up

Gustavo is correct. You need to demonstrate through calculations that the "available" reclaimed water and rainwater meets or exceeds the demand. "Available" is the key word. What the reviewer is effectively saying is that the tank size doesn't necessarily equate to available capacity at a given time. Despite the tank size, it's possible that the needed capacity for the irrigation demand is not available in the storage tank.

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Derek Seifert LEED Green Associate, Landscape Architectural Intern Anderson Engineering of MN
Jun 20 2016
Guest

Stormwater pond outside boundary

Project Location: United States

Hello all,

Our project is intending to use a LEED boundary that is only a portion of a larger site. The larger site is a National Cemetery and the LEED boundary includes only the areas that are immediately servicing the buildings on site. As part of meeting credits SSc6.1 and 6.2 (stormwater) we are designing a wet retention pond outside the LEED project boundary that will capture the runoff for the LEED project boundary land as well as a majority of the larger site.

The larger site's irrigation system will be drawn from this wet pond, and is intended to supply the irrigation needs for the larger site, which then includes the land within the LEED boundary. Only in times of drought would the irrigation be supplied by a potable source, but based on our calculations we should easily reduce the need for 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. for irrigation by 50%.

Since this wet pond is collecting the stormwater from the LEED site and the larger site, and supplying the irrigation for both the LEED site and larger site, can this constructed retention pond water be considered "captured on-site rainwater"?

Any advice would be most appreciated, thank you.

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William Weaver LEED Fellow, JLL Jun 23 2016 LEEDuser Member 1998 Thumbs Up

Hi Derek,

We had a similar instance wherein we developed an office building as part of a larger office park. The irrigation system was not specific to our project's boundaries and was continuous throughout the entire park. Likewise, it was supplied by a large retention pond in the park, that was also not within our boundary.

For the purpose of documenting this credit, we provided a narrative explaining that we were calculating the irrigation water use for the entire area served by the irrigation system, not just the vegetated area within our LEED boundary. To demonstrate that the pond met the irrigation demand, we provided the following:
1. Topographical as-built of the pond that illustrated the pond's normal permanent pool elevation, and maximum elevation;
2. Calculations showing the permanent pool volume - used to compare against the calculated demand to show that the pond's normal permanent capacity exceeded that of the irrigation demand;
3. Copy of the irrigation consumptive use permit confirming that the irrigation system is supplied from the pond. Irrigation system drawings could have been used for the same purpose, but we were unable to locate any irrigation system design drawings for the existing irrigation system, hence we had to provide the consumptive use permit as our means of proof.

That may be more than was necessary to sufficiently document credit compliance, but we were able to demonstrate 100% reduction in 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. use, and 52% reduction in total water applied with this strategy. We received no review comments.

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Eric Bautista Managing Consultant, LEED™ AP (BD+C Specialty) EB Project Management
Jun 16 2016
Guest
2 Thumbs Up

Reject Water from Reverse Osmosis system?

Dear Fellow LEED Users,

In the Irrigation Design Case tabulation, can I declare "reject water" from reverse osmosis equipment system of campus, as the source of non-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.?

Thanks in advance,
Eric

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Ralph Bicknese Principal Hellmuth + Bicknese Architects
May 12 2016
LEEDuser Member
450 Thumbs Up

"Special Conditions" for baseline

Project Location: United States

For our current project, virtually 100% of landscaping is turfgrass using 62.5% efficient rotors, usually a difficult combination for achieving 50% reduction. We have a unique situation where, if allowed, we present the existing system/techniques as our ‘Baseline Case’ and compare that to the proposed automated system 'Design Case' which is much more efficient. This would require convincing USGBC to consider these “Special Conditions” (the wasteful existing conditions vs the better proposed system) as a credible variation/approach in assessing water-efficiency. Has anyone had success trying to achieve this credit using this type of method or have suggestions for strengthening our case?

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Rahul Yadav
May 12 2016
Guest
9 Thumbs Up

Meeting the 5% landscape requirements with planters

Hi, The credit says that for applying the points, minimum 5% of the site area shall have planters, garden etc. Does the potted plants are counted under planters.

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Carlie Bullock-Jones, LEED Fellow, WELL AP Principal, Ecoworks Studio May 15 2016 LEEDuser Expert 3327 Thumbs Up

Hi Rahul,

Note that the LEED Reference Guide states that for buildings without vegetation on the grounds, teams can earn points by reducing the use 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. for watering any roof and courtyard garden space or outdoor planters, provided the planters and garden space cover at least 5% of the building site area (including building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. area, parking footprintParking footprint refers to the area of the project site occupied by the parking areas and structures., etc.). If the planters and garden space cover less than 5% of the building site area, the project is ineligible for this credit.

Hope this helps!

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group May 18 2016 Guest 198 Thumbs Up

Depends where it's situated, I failde to find it once again, but I remember precisely that it was some clarification, that plants in planters/pots at patio/inner yard/atrium (smth like that) are not falling under WEc1... Am I wrong, or somebody also remeber this 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?

I found it:

"An addendum, ID#100000352 dated 07/19/2010, defines the landscaped area to be considered. It excludes the building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint. so interior plantings are not considered. In any case, interior planting cannot avoid irrigation."

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GISELA FARHAT DE ARAUJO
May 03 2016
LEEDuser Member
24 Thumbs Up

ETo Unit

Project Location: Brazil

I would like to know which unit of measurement should include the value of ETO (Reference evapotranspiration rate). Im Brazil we normaly use mm. should i put in Inches?

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William Weaver LEED Fellow, JLL May 03 2016 LEEDuser Member 1998 Thumbs Up

Hi Gisela,

When the project was first registered, the project administrator should have selected a unit of measurement for the project - imperial or metric. That unit of measurement should be consistent throughout your project documentation.

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GISELA FARHAT DE ARAUJO May 03 2016 LEEDuser Member 24 Thumbs Up

Thank you Willian. But where can i see this option made in leed on line?

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GISELA FARHAT DE ARAUJO May 05 2016 LEEDuser Member 24 Thumbs Up

William, when we made the first register, the leed on line version didn´t have this kind of choice.

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William Weaver LEED Fellow, JLL May 05 2016 LEEDuser Member 1998 Thumbs Up

Gisela, the easiest way I can think to check is to go to MRc2: Construction Waste Management. If the options in the drop down box are Ton or Cubic Yard, then your project is set up in Imperial. If it says, Tonne, Cubic Meter, Kilograms or some other option, then your project is set up in Metric.

Whichever system of measure your project is set up in, you want to make certain that you use the same system throughout your documentation, else you will confuse your review team and very likely have a lot of review comments.

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M; CxA: Green Rater in Training, Revitaliza Consultores May 05 2016 Guest 1504 Thumbs Up

Hi Gisela, if you didn't have the chance to choose between Imperial or Metric, I would assume it is Imperial Units. The ET0 coefficient is entered in inches in this form.

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GISELA FARHAT DE ARAUJO May 06 2016 LEEDuser Member 24 Thumbs Up

Thank you Gustavo

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Muriel Alvarez LEED Green Associate Samconsult S.A.
Apr 19 2016
LEEDuser Member
5 Thumbs Up

Non potable water reservoir - WEc1 -NC 2009

Project Location: Uruguay

We are certifying a project NC 2009 and we are counting in our credit with a non potable reservoir outside the LEED Boundary but is within the limits of the property. The non 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. reservoir water is untreated water waste from different buildings within property limits. Can we use it for this credit?
Thank you

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group May 18 2016 Guest 198 Thumbs Up

You can take a look at this question: "Retention pond off site" here - http://www.leeduser.com/credit/NC-2009/WEc1?page=2#comment-64252

Since in your case it's not a natural waterbody (I suppose it is smth like concrete basin) it's not a problem. But if I were reviewer, my first question would be - is it enough water for your project, since if this reservoir is filled by different buildings, and it is treated to the standard (by the way, is it so?), that can be used for watering, so other building probably also use it.

So better to submit 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.

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Lauren Bellamy
Mar 01 2016
Guest
93 Thumbs Up

What areas to include for planted areas?

Project Location: United States

We have a project where only about 1/3 of the planted area will be irrigated. The other 2/3 is planted with plants and groundcover that will not require irrigation.

Do we just include the SF of irrigated planted area in the credit or do we include all SF of planted area to calculate the credit for 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. reduction?

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Karin Miller Sustainability Manager, YR&G Mar 10 2016 LEEDuser Member 454 Thumbs Up

Lauren - you'll need to include the entire landscaped area.

As you fill out the form, you'll select the option for "The landscaping and irrigation systems have been designed to reduce irrigation water consumption from a calculated baseline case." and separate out by row based on landscape type and whether it's irrigated or not so you can account for the difference in the design case. The baseline case will reflect 100% irrigated. The design case will reflect the 33% irrigated.

Hope that helps!
Karin

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Omar ElRawy Building Engineer, LEED AP BD+C EA Building Consultants
Feb 24 2016
Guest
1097 Thumbs Up

Basement That Extends to Plot line

Project Location: Egypt

Hi,
My project has two levels basement that extends to the land's plot line, while the above-grade floors are much smaller areas than the basement area. And the design includes vegetation above the basement slab, all around the above-grade building, which is considered to be the landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios..

My question is, is this vegetation considered to be "vegetation on the grounds" or not?

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group Mar 11 2016 Guest 198 Thumbs Up

I suppose that yes - it can be considered, but under some conditions - it depends on how deep under the surface is the upper slab of the basement floor – am I right that all area that is not under building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint. is over the basement floor? If the ground over the slab is deep enough – for my opinion 1-1,5 metres (3-5 feet) from the “zero” level – it could be counted as thickness of soil that can provide almost as natural conditions to plants. So vegetation on such cover can be considered as “on ground”. If the depth is 20-30 centimeters (up to 1 feet) – it’s definitely not enough to provide normal vegetation of plants – but in such case, if all area above basement is considered as a huge planter, you can try to pursue 5 % rule (I suppose that area over the basement is more than 5 %). If the depth is between 0.3-1 metres (1-3 feet) – it depends on type of vegetation – for grass and bushes such thickness would be enough, for trees – not.
If I were you I would try this strategy to convince reviewers, what you have to loose, and this credits are pretty simple and contributing good number of points in relation to the effort.
Also, you can take a look at inquire (and answer) of Jens Apel (Jul 25 2014) – in her/his case they used “planting bed with a depth of approx. 1.5 meters”.

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Veronika Kozlova
Feb 15 2016
Guest
6 Thumbs Up

Defining landscaped areas

Dear all,

Our project has a landscaped area that includes trees, shrubs and grass. We have a number of trees and number of shrubs to be planted but we do not have area in sq feet that is allocated to them.
Could you please advise on what will be the most acceptable way to calculate the landscaped areas?
Thank you

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Rita Haberman Brightworks
Jan 07 2016
LEEDuser Member
146 Thumbs Up

Community Garden and Reclaimed Water

Project Location: United States

Our project is using greywater for landscape irrigation, likely 100%. The project will have a small community garden where residents can grow their own food for consumption. Because these are edible, we are not using recycled greywater for the community garden.

Has anyone had experience with excluding this type of landscaping from the irrigation calculations? Nearly 100% of the landscaping will not require permanent irrigation systems EXCEPT for this small garden. It is still unknown if the community garden will be hooked up to a 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. irrigation system or if it will be hand watered and managed through the residents and/or a third party.

Thank you.

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Angela Fiorenza LEED AP BD+C, LEED Project Reviewer, Senior LEED Specialist , Epsten Group Jan 07 2016 Guest 44 Thumbs Up

Hello Rita,

You are in luck! There is a published LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. (LI 10155), which allows vegetable gardens to be excluded from the WEc1 calculations.

Best Regards,
Angela Fiorenza

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Rita Haberman Brightworks Jan 07 2016 LEEDuser Member 146 Thumbs Up

Thanks for the quick help!

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Francis McNulty OCSC
Nov 19 2015
LEEDuser Member
97 Thumbs Up

Manually Watering instead of Temporary Irrigation?

Project Location: Ireland

Hi All,

For a water efficient landscape, with native plants and no requirements for irrigation except a temporary irrigation system for 12 or 18 months.

Can a person within the maintenance team of the building manually water the plants for the first 18 months instead of installing temporary irrigation?

If so, what documentation is required to ensure points are achieved with this strategy?

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Nadav Malin USGBC LEED Faculty, President, BuildingGreen, Inc. Nov 19 2015 LEEDuser Moderator

Hi Francis,

That approach totally works. There is no requirement that you "install" temporary irrigation, just that you NOT install permanent irrigation. The main documentation challenge is for the first part, about the 50% water demand reduction--you still have to show that your plantings are that much less water-hungry than typical.

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Francis McNulty OCSC Nov 19 2015 LEEDuser Member 97 Thumbs Up

Hi Nadav,

Thank you for your response, just to clarify are there any requirements that must be shown in terms of the efficiency of temporary hand irrigation? Do you need to provide details as to expected quantities/restriction measures for water and a detailed plan on the strategy?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 27 2015 LEEDuser Moderator

Francis, I haven't seen any rigorous approach to the questions you ask on hand watering relative to projects providing those details, nor any specific requirements. I would go with a common sense approach.

If you learn anything more specific along the way, please post back here so we can all learn!

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Annalise Reichert Project Manager stok
Jul 29 2015
Guest
361 Thumbs Up

Future Reclaimed Water Service

Project Location: United States

I am working on a project that is installing reclaimed/recycled water lines to the project, with the goal to offset 60% of irrigation water with recycled water. However, the local water service currently does not have the capacity to provide reclaimed water to the site. This service may become available in the next few years, but a definitive time frame has not yet been given.

Can we still claim the 60% 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. use offset for the purposes of the irrigation credit? Is there a specific time frame that project needs to actually be provided with recycled water (i.e. within 2 years of operation?)

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group Sep 24 2015 Guest 198 Thumbs Up

Since this credit evaluates the regular operation of the building, I suppose, that would be usefull official letter from the local water service, that states/claims that in "x months" reclaimed/recycled water lines would operate at 100 % capacity.

According to the period, at wich temporary irrigation system for plants and/or additional irrigation for plants establishing is allowed (18 months - p. 183 of Refguide and LEED Reference Guide addendum from 7/19/2010), I suppose, that the mentioned above period of "x months" must be not more than 18 months from assumed building occupation/operation start up.

Does it sound reasonable?

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PAULA HERNANDEZ MRS. INGENIERO MARIO PEDRO HERNANDEZ
Jul 27 2015
LEEDuser Member
960 Thumbs Up

Green Wall

Hi, our project is considering a green wall with drip irrigationDrip irrigation delivers water at low pressure through buried mains and submains. From the submains, water is distributed to the soil through a network of perforated tubes or emitters. Drip irrigation is a high-efficiency type of microirrigation.. How do you declare that? I'm thinking of adding a spread sheet describing the types of spaces (green roof, planters, vegetation on ground and green walls) describing the size of each, plant composition and which is considered for each credit (ie, the green wall would count towards water consumption in WEc1 but NOT count towards native vegetationPlants indigenous to a locality (native) and adapted to the local climate; they require limited irrigation following planting, do not require active maintenance such as mowing, and provide habitat value. or open space in SSc5.1 and SSc5.2). Am I on the right track? Thanks!!

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, JLL Jul 27 2015 Guest 6375 Thumbs Up

You're definitely right regarding SSc5.1, per this LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #5385.

For WEc1 I'd think the evapotranspiration rate could be really high. I had a palette planter of herbs leaned up against my metal balcony and the water evaporated so fast.

I'm not sure that vertical vegetation would actually fall under the strict definition of "landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios.." The landscape area of the site is the total site area less the building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., paved surfaces, water bodies, areas being left in a natural state, and patios." ID#100000449

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PAULA HERNANDEZ MRS., INGENIERO MARIO PEDRO HERNANDEZ Jul 27 2015 LEEDuser Member 960 Thumbs Up

Thanks Kathryn! So, what do I do?Do I declare the consumption in WEc1? This wall is in a shaded area, so I'm not so afraid of ETEvapotranspiration (ET) is the loss of water by evaporation from the soil and by transpiration from plants. It is expressed in millimeters per unit of time., but of the overall water balance

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Angela Fiorenza LEED AP BD+C, LEED Project Reviewer, Senior LEED Specialist , Epsten Group Jan 07 2016 Guest 44 Thumbs Up

Chiming in here Paula,

You may have already submitted this project, but in case you haven't, I wanted to confirm that you should include all landscaped areas on the outside of the building or on the project site in the WEc1 calculations, including the green walls. You may also want to mention in a narrative that the area is anticipated to be shaded to justify the ETEvapotranspiration (ET) is the loss of water by evaporation from the soil and by transpiration from plants. It is expressed in millimeters per unit of time. value used. I hope this helps! Good luck to you.

Best Regards,
Angela Fiorenza

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Julien Lafond Altanova, LLC Jan 27 2016 LEEDuser Member 22 Thumbs Up

Hi Angela,

Glad to see your comment here. Have you gotten an exterior green wall approved as counting towards the minimum 5% landscaped area for WEc1? Did you need to submit 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 for this? I ask because we have a project that will only meet this 5% minimum by including the exterior green wall area.

Thanks for your help,
Altanova

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Angela Fiorenza LEED AP BD+C, LEED Project Reviewer, Senior LEED Specialist , Epsten Group Jan 28 2016 Guest 44 Thumbs Up

Julien (Altanova),

Good catch, my previous response wasn't entirely clear on that issue. I believe that the most appropriate way to calculate the vegetated wall area for the purposes of the WEc1 calculations is to base that value on the area of the planting beds that host the plants, and not on the wall area that is anticipated to be covered by the vegetation. I'm not aware of any formal guidance regarding this issue though, so 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 may be appropriate to request confirmation.

Best,
Angela Fiorenza

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group Jan 29 2016 Guest 198 Thumbs Up

At one of the projects I counted only area that host a plants (horisontal) not the covered by plants green wall area (vertical).

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Jorge López de Obeso Architect / Environmental adviser EA Energia y Arquitectura
Jun 05 2015
LEEDuser Member
996 Thumbs Up

Turf grass with trees

Good evening everyone,

I had some doubts determining the species factorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species. while filling out the credit form. The landscaped areas in our proyect includes turf grass mixed with trees. In addition, the trees have low watering needs while the turfgrass' species factor is high.

Which vegetation type is more suitable in relation to it's water consumption for this situation?

In cases of mixed vegetation (shrubs, trees and groundcover) with different water consumption needs, is it posible to adjust the Ks value or do I have to consider the highest?

Thanks in advance!

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Alexia Anastassiadis Jul 27 2015 Guest 504 Thumbs Up

Hi Johanna,I would use the Mixed Vegetation category with the high Ks value, since I figure the whole area under the tree is turf. I had a project where half of the area under the tree was turf and the other half was a gravel path, so we declared half as Mixed Vegetation with a high Ks value and the other half with just the Ks value corresponding to the tree (and that was quite some work!). Hope I helped!

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FABIO VIERO Head of Sustainability Manens-Tifs s.p.a.
Jun 04 2015
LEEDuser Member
1187 Thumbs Up

Greenroof, water retention with perlite

I was wondering if anyone had already used a roof garden including the perlite.

Perlite is a volcanic rock effusive varying in color between gray and pink, whose chemical composition is similar to that of dacites and rhyolites. It has the ability to expand its volume up to 20 times when compared to the original flow rate.
The peculiarities of the system including the perlite is due to the limited thickness of the package that allows engraftment and development of plant species provided in 11 cm thickness, bringing the storage value total water up to 45 l / m2 (perlite's saturation value)

I think this roof system can be included into WEc1 calculation by reducing the Ks factor since this is not a typical cistern or pond retention system but it releases water directly at the roots without use of any irrigation system.

Any suggestion?

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Alexia Anastassiadis Jul 27 2015 Guest 504 Thumbs Up

Hello Fabio,
Ks is the Species FactorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species., it is a characteristic of the plants you will use, the soil type should not affect the Ks.
We do lots of projects with green roofs, all of them have special substrates that we engineer, according to the type of planting, exposure, rainfall patterns, etc and we still use a High Microclimate factorMicroclimate factor (kmc) is a constant used in calculating the landscape coefficient. It adjusts the evapotranspiration rate to reflect the climate of the immediate area. for the green roofs, since the conditions there are usually far worse than those on the ground, still what substrate engineering allows us to do, is to still use low Ks species and no permanent irrigation on those roofs, so that's plenty of help in making a low water consumption project.

What we do in such cases is that we declare the area a non-irrigated and leave the Ks space blank and the irrigation space blank so you don't add a water consumption for that category on the LEED form.

For instance, lets say that your project earns credit SSc2 (if not, you can not include the green roof in your calculations) and have an irrigated garden in the ground level and then the non-irrigated green roof (usually an extensive green roof is all made up of ground covers).
So, you would have all the irrigated categories of your garden (trees, shrubs, mixed, groundcovers, etc) and then the Non-Irrigated Groundcovers of your roof, with a 0 Ks value and no irrigation (the plants don't have 0 ks, it is just what you do in order to fill the form and have zero consumption for that category).
Hope this helped!! All the best!

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Margaret Manuel Tetra Tech
May 14 2015
LEEDuser Member
123 Thumbs Up

"Landscape = 5% of the total site area" Rule

Project Location: Djibouti

I've seen a couple different comment threads on this, so I just want to make sure we're doing the right thing, as we have 5 points pending. The "Bird's Eye View" of this credit (above) states the following: "Projects with landscaping on less than 5% of their site area cannot earn points here, so consider planters or small gardens to meet that threshold."

It seems to me this requirement has been taken out of context. If one reviews the instructions from LEED User online for filling out this credit - the 5% is required if using PLANTERS ONLY to achieve this credit. On page 1 of the LEED template, if you click on the box that states "Project conditions do not allow for installation of vegetation on the grounds. Therefore planters, a vegetated roof, and/or a courtyard landscape have been installed to achieve credit compliance. (Optional)" ...then, and only then - 5% becomes criteria, correct?

We have a project in Djibouti, Africa. There are many many miles and miles, where the ground is basically dirt and rocks. We are providing 30+ native trees in the ground, surrounded by white rock mulch. We have 1 large planter, but everything is irrigated 100% with reclaimed grey water.

After submitting for Design, we received the following comment from USGBC:
"1. The landscaped area reported in the form (450 square feet) is significantly less than 5% of the total site area reported in PIf2: Project Summary Details (97,865 square feet). As outlined in the LEED BD+C v2009 Reference Guide, the vegetated area must cover at least 5% of the project site area (including building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. area, parking footprintParking footprint refers to the area of the project site occupied by the parking areas and structures., etc.) to be eligible for this credit. Note that reducing the use 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. for watering any roof and courtyard garden space or outdoor planters is an acceptable approach to earn this credit, provided the planters and garden space cover at least 5% of the total site area. Provide documentation confirming that the landscaped area is equal to at least 5% of the total site area reported in PIf2. Note that the hardscape and rock mulch areas below the tree canopies are not considered vegetated."

Would we be wrong to challenge the USGBC Reviewer on this? Our site DOES allow for vegetation on the grounds. We are providing trees on/in the ground. Does the 5% rule apply to our case? If so, how and where is this specifically documented?

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, JLL May 15 2015 Guest 6375 Thumbs Up

I'm not sure if you'd have any luck but maybe you could use the logic from LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #2487...project in Dubai got approval to count desert "natural open space mimicking the surrounding ecosystem" as "vegetated open space."

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Margaret Manuel Tetra Tech May 15 2015 LEEDuser Member 123 Thumbs Up

Thanks Kathryn! We submitted onSSc5.2 and I had given up hope...but will now use #2487 as justification. :-)You're awesome! I'm still curious on how you & others view the 5% rule. Do you think it's applicable if we have palm trees and olive trees planted in the ground? Or do you think the intent is to provide a 5% oasis in the desert?

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group May 18 2015 Guest 198 Thumbs Up

"...then, and only then - 5% becomes criteria, correct?" - I suppose it's correct.

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Cindy Estrada LEED AP BD&C SDS Architects, Inc.
Apr 22 2015
LEEDuser Member
918 Thumbs Up

Option 1 - Reduction Combination?

Project Location: United States

We are looking at this credit for our project and after reading a few posts and reviewing the WEc1 form in LEED online my question is; the NC 2009 reference guide states that "Reductions must be attributed to any combination of the following items." And then it goes on to list the items, but the LEED WEc1 form doesn't seem to request more than baseline vs. design case calculations does this become apparent within the calculation tables?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 27 2015 LEEDuser Moderator

Cindy, you don't have to calculate the exact contribution of each item to the reduction, if that answers your question.

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Renaud Gay Shanghai Pacific Energy Center
Apr 20 2015
LEEDuser Member
231 Thumbs Up

water retention agent

Project Location: China

Hi,

I was wondering if anyone already used water retention agents added in the soil, such as acrylamide in any project and how this was documented.

Thanks!

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William Weaver LEED Fellow, JLL Apr 20 2015 LEEDuser Member 1998 Thumbs Up

I think this concept was discussed a while back when someone was proposing a hidrogel underlayer. The easiest thing to do, from a documentation standpoint, would be to use the 'low' species factorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species. for the vegetation type(s) on your design case, and assign either the 'average' or 'high' species factor for the same vegetation type(s) on your baseline case. That would enable you to account for the differentiation with the soil additive included.

I'm not suggesting it will be the most accurate tabulation of your water use, but I don't believe there's really any other way to account for it.

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Laura Charlier LEED Services Director Group14 Engineering
Apr 13 2015
LEEDuser Member
606 Thumbs Up

Open planters definition

What does “Open Bottom Planters” mean? I assume they drain to ground water – and not to a weep hole in the face of the wall, and then to storm? Thanks.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 27 2015 LEEDuser Moderator

Laura, I haven't seen a definition of this, but my assumption has been that they drain to the ground, not to a storm sewer.

Nice to see you at Greenbuild last week!

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Yueling Chen HVAC engineer ECO
Jan 19 2015
Guest
15 Thumbs Up

Sample download

I just purchase a premium membership, but i can't download the word & excel version sample in Documentation toolkit, like Sample Narrative for WEC1-Option 1, Option2 Path1 & Path 2 in WE C1. Can you tell me why?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 30 2015 LEEDuser Moderator

Yueling, I apologize for the slow response, and the original difficulty. Please feel free to contact us directly if you ever have a problem like this in the future—the contact link is in the right sidebar.

This problem has been fixed and those documents are now downloadable.

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Alicja Bieszyńska Skanska
Jan 07 2015
LEEDuser Member
1399 Thumbs Up

Irrigation area

Project Location: Poland

If my project consists of 10,000sf of greenery but only 3,000sf is irrigated, do I need to insert 10,000sf or 3,000sf as a total area in the LEED Online form (both baseline and design case)?

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William Weaver LEED Fellow, JLL Jan 07 2015 LEEDuser Member 1998 Thumbs Up

Use only the area that is irrigated.

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Alicja Bieszyńska Skanska Jan 07 2015 LEEDuser Member 1399 Thumbs Up

Thank you William!

I was worried that this area will not be equal to the amount I have in SSc6. stormwater calculations.

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William Weaver LEED Fellow, JLL Jan 07 2015 LEEDuser Member 1998 Thumbs Up

You could use the 10,000sf number, but you would label the 7,000sf as non-irrigated in both the baseline and design case, and set your IE to 0. The resultant will be the same.

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Tamary Alvarez LEED AP BD+C, Sustainability & Commissioning Specialist Commissioning Agents Inc.
Dec 16 2014
LEEDuser Member
47 Thumbs Up

Runoff/Gully Water

Project Location: United States

Our project's environmental site assessment has documented a gully resulting from the runoff of the adjacent siteA site having at least 25% of its perimeter bordering sites that has been previously developed. Any fraction of the perimeter that borders waterfront will be excluded from the calculation. For the purposes of this definition, a street or roadway does not constitute previously developed land. dumping into our site. We are using this water for our cooling towers and irrigation. I think we can consider this nuisance water and comply with this credit's intent. Thoughts? Thanks!

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William Weaver LEED Fellow, JLL Jan 07 2015 LEEDuser Member 1998 Thumbs Up

That's a tough one. Some reviewers will probably interpret the gully as a drainage/irrigation ditch and consider it a potential source 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.. Your best bet is to provide a narrative describing it as nuisance water, and explain how it is being captured for reuse along with details of the size/capacity of the containment.

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Tamary Alvarez LEED AP BD+C, Sustainability & Commissioning Specialist, Commissioning Agents Inc. Jan 21 2015 LEEDuser Member 47 Thumbs Up

Thanks William!

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Heather DeGrella Sustainability Design Leader Opsis Architecture
Dec 12 2014
LEEDuser Member
1558 Thumbs Up

Success substituting the LEEDv4 approach for WEc1 in v2009?

Has anyone had success using the LEEDv4 approach for WEc1 in v2009? It is not in the list of officially approved substitutions but it seems like a logical substitution.

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deborah lucking associate, fentress architects Apr 25 2016 LEEDuser Member 2341 Thumbs Up

Heather,
I sent that question (via "Feedback" on LEED Online) and got this reply: “that one is not in the list [of approved LEED Credit substitutions] but you are welcome to submit 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 to request it. In writing a CIR describe why you think it's applicable.”

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carla cruz
Dec 05 2014
LEEDuser Member
2893 Thumbs Up

Temporary Irrigation but Reused Water

Has anyone secured a point under WEc1 without using either drip or sprinkler irrigation system? Our project outside US is looking to achieve points through manual irrigation (hose bib), however the water will come from non-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. sources i.e. rainwater and STP. I understand that to secure two (2) points there should be a calculated reduction of 50% non-potable for irrigation. If the calculated amount of water processed by the STP managed to offset 50% of the potable water demand for irrigation, are we qualified to earn two points?

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Peter Doo President, Doo Consulting, LLC Oct 21 2015 LEEDuser Member 3504 Thumbs Up

We are working on a project that's doing the same thing. Any luck?
Do we have to calculate the the amount of water that's been fed through the hose bibs? it's only temporary

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Michelle Rosenberger Partner ArchEcology, LLC
Nov 23 2014
LEEDuser Member
7667 Thumbs Up

Controller Efficiency

I see several threads attempting to get an answer on how one demonstrates controller efficiency and the most prevalent answer seems to be just use 1 because no other values can be substantiated by manufacturer documentation. Is that still the prevailing opinion?

It seems clear that a value of 1 is meant to reflect the default position of not using weather based smart controllers for irrigation. So it seems obvious that a weather based controller would be preferable and incentivized by a lower value. The USGBC guidance does not seem to suggest complex exceptional calculations are required in their reference to just provide manufacturer backup. Yet, they also suggest a possible range and do not just provide a default value to be used with such a controller.

Given that manufacturers do not seem to provide a CE in their documentation, do we actually believe that a high efficiency drip irrigationDrip irrigation delivers water at low pressure through buried mains and submains. From the submains, water is distributed to the soil through a network of perforated tubes or emitters. Drip irrigation is a high-efficiency type of microirrigation. system with a weather based controller should have to use a CE of 1 and has to somehow find an exceptional way to achieve this credit? Or ultimately is it simply sufficient to provide normal product data backup that indicates a weather based controller is being used?

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Carlie Bullock-Jones, LEED Fellow, WELL AP Principal, Ecoworks Studio Nov 25 2014 LEEDuser Expert 3327 Thumbs Up

Hi Michelle,

You are correct, if the irrigation system has no weather-based controllers or moisture sensor systems, a CE value of 1.0 should be used in the calculation (and no back up data is required).

Note that for projects registered after the February 2, 2011 Addenda, any percentage reduction in water use from controllers cannot exceed 30%; therefore, the CE may range from 0.7 to 1.0.

I am not aware of any default values that can be used for controllers. To claim the CE value utilized, data and/or supporting calculations from the manufacturer must be provided to verify the savings. If the manufacturer data states that the controller provides a range (for example, 20% – 30% efficiency) then I would utilize the lower value (0.8) in the calculations.

Hope this helps!

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Michelle Rosenberger Partner, ArchEcology, LLC Nov 25 2014 LEEDuser Member 7667 Thumbs Up

Hi Carlie,
Thanks for the response. The manufacturer's data is not providing us with a helpful xx% efficiency claim. So I am trying to determine what "detailed calculation" done by the landscape architect would substantiate this.

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