NC 2009 WEc1: Water Efficient Landscaping

Joshua Radoff replied Principal, LEEDuser Primary Author, YRG sustainability Aug 31 2009

This caveat applies to all project types, whether you've got a zero lot line site or a sprawling parking lot. The intent here, I believe, is to improve over the previous version of LEED, that didn't stipulate how much landscaping you needed to get the credit. So in theory, with the older system, you could have one planter, irrigate it efficiently, and get the credit. Now there is a minimum amount of site area that needs to be vegetated to qualify.

Joshua Radoff replied Principal, LEEDuser Primary Author, YRG sustainability Sep 08 2009

Balaji,
You make a good observation. It certainly seems that USGBC is creating a back door approach for projects without a shred of landscape on the ground. Perhaps the thinking is that if you have a large site, and you've gone and paved paradise and put up a parking lot, then you probably wouldn't have the 5% site coverage with planters and such. It's just too many planters.

Therefore, the application here would only be for urban, zero lot line-ish sites that don't have much ground to work with. In this case, it would be good to give these projects some parameters such as how much landscaping is required to qualify for the credit, which they have now done.

We have a call in to see if this is an accurate assumption or not, and I'll provide another post if we learn something new.

Thanks,
Josh

Joshua Radoff replied Principal, LEEDuser Primary Author, YRG sustainability Sep 10 2009

One follow up note... We received some guidance here from GBCI. A very prompt reply. The only concern is the use of the phasing "we believe":

"Though the Reference Guide and credit submittal form suggest otherwise, we believe that the 5% minimum landscaped area requirement was intended to apply to all projects whether the landscaped areas are ‘natural’ in-ground/at-grade areas, or planters, roof gardens, etc. If the requirement didn’t apply to both conditions, projects could leave a tiny sliver of in-ground planted area (say, less than 1% of the total site area) on almost any site and achieve the credit, while a similarly situated project with planters covering 4% of the site could not achieve the credit. A very small area (e.g. 1% site coverage) could meet the requirements with minimal plantings, but have relatively little impact on total water usage, whether it was irrigated or not. That kind of minimal differentiation between the design and baseline cases clearly wouldn’t meet the intent of the credit."

Brenden McEneaney replied Green Building Program Advisor, City of Santa Monica Feb 04 2010

This general discussion may suggest somewhat of a rethinking of the water use reduction credits - namely that water use could be treated a bit more like energy and that we may want to measure total gallons (or percentage) 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. saved rather than differentiating between indoor and outdoor water use.

Here in Southern California, irrigation systems are needed. Even if a non-potable source is provided, a potable make-up is usually required as a backup. But rainwater systems need to be very large (often prohibitively so - both financially and environmentally) to meet the annual needs of the landscape, since what little rain we get falls in a short window. A project here that achieves 95% landscape water savings seems to me to be achieving a far greater environmental benefit (even before looking at the inevitable urban runoff) than a project in a rainy climate that doesn't install an irrigation system, but more LEED points would be awarded the latter project...

Jean Marais replied b.i.g. bechtold INGENIEURGESELLSCHAFT MBH Sep 10 2009

Ignore very last unfinished sentence.

Shannon Gray replied Consultant, YRG sustainability Sep 10 2009

Sorry for the confusion, the image/diagram in the Bird’s Eye View section of LEEDuser is inaccurate and there is no exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point for this credit. This will be updated on the website shortly.

This credit allows projects to earn a maximum of 4 points. In order to attain all 4 points you must meet option 2 by reducing 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. applied by 100% AND by reducing total water applied by 50%. For example, if your project reduces potable water by 100% and the reduction for total water applied is only 20% you will only earn 2 points.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Sep 29 2009

Heather, I hope someone will correct me if they have a different experience, but irrigation of green roof landscaping would fall under WEc1, and would not be allowed past one year, for plant establishment. I wonder if the manufacturer making this stipulation is aware of the LEED implications?

Shannon Gray replied Consultant, YRG sustainability Oct 28 2009

I'd write 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, I know there has been a lot of discussion around this and I imagine you could get away with a two year establishment period...three might be more difficult. But, if you have a good argument it could work.

Shannon Gray replied Consultant, YRG sustainability Jan 04 2010

That is a good question. On LEED for Schools projects you can decide to include or exclude playing fields for the landscape irrigation calculations but you must then be consistent across all credits. So, if you exclude the playing field from the landscape irrigation calculation you must also exclude it from the open space calculation. I would imagine you can take a similar approach in this situation, but it might be worth writing 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 have an official say on the subject.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jan 22 2010

Erik, why are you including the existing lawn areas in the LEED boundary if they are not a part of the project scope? Seems like the simplest thing here would simply be to leave them out of all your credit calcs.

That wouldn't help you with this credit, of course—but it's not clear to me how you are planning to earn this credit, anyway? Are there other landscaped areas you are hoping to use to earn the credit?

Might be better to include the landscaped areas in the project boundary to at least help with other SS credits.

Ben Stanley replied LEED Consultant, YRG sustainability Jan 29 2010

Rick,

There's nothing in the LEED for Schools 2.0 rating system or reference guide to explicitly exclude planters from the landscape irrigation calculations so you could give it a try. However, given the direction of the current rating system, I wouldn't count those credits as "in the bag" until after the design review.