Water Efficiency (LEED WE Category)

I don’t think it’s a surprise to anyone that Water Efficiency is a LEED category.  The Water Efficiency category addresses both indoor and outdoor water usage.  A portion of our outdoor water story will be addressed in a separate post – we’re utilizing a rainwater harvesting system that direct 100% of the rainwater that hits our roof to cisterns.  Look for that post in a few days.

I’ll address our outdoor water usage first.  The irrigation portion of our outdoor water story is simple.  We’re installing a high-end, very efficient irrigation system that will have about 10-14 zones.  We are directing water exactly where we need it and not watering where we don’t.  There are several requirements to achieve points for your irrigation system, some of which are fairly typical installation methods, but some are not.  A sample follows – (there are 11 and you get a point for each that you use up to a maximum of 3 points):

  • Install an irrigation system designed by an EPA Water Sense certified professional.
  • Install a central shut-off valve.
  • Use drip irrigation for at least 50% of the landscape planting beds to minimize evaporation
  • Check valves in heads.

However, we’re not going for points based on the irrigation system itself.   Fortunately for us, our Landscape Architect is installing a drought-friendly front and back yard that reduces our irrigation demand by 66%.  Yes, 66%.  The calculation that appears on page 50 of the LEED for Homes Rating System is daunting (fortunately, our Landscape guy did the calculation for us, and I’m attaching it here–>irrigationcalculationwe23).  We will be getting the full 4 points in the WE2 category!  NOTE:  a reduction in irrigation demand makes you eligible for points in the Sustainable Sites category which I addressed in a prior post).

Indoor water use is the second key component of the WE category.  It’s pretty obvious that the lower flow your plumbing fixtures, the higher the points.  So we’ve installed 3 really groovy dual-flush toilets in all the baths except the studio bath (but that’s a low flow, too).  And we’re trying going with very high efficiency faucets in the baths as well (defined as <1.5gpm).

I will say this about low flow plumbing fixtures:  it’s hard to get very high efficiency fixtures in very modern and stylish designs.  As an example, here’s our choice for our bath faucets (flow rate of 2.2gpm), but to get them down to “very high efficiency” (<1.5gpm), we have to add in low-flow aerators – they just don’t make the faucets “very high efficiency” without the use of an aerator.  AND it took us a bit of an effort for Kohler to give us information about the aerator’s impact on the flow rates.

I will confess an eco-sin here:  I love showers, and I couldn’t bring myself to use a high efficency/low flow shower head in my master bath.  I love the water too much!  We gave up a point because of this, and I hope I don’t live to regret it!

Our plumbing fixture budget wasn’t enough to cover our choices, but that’s because we went a little higher end than originally anticipated, not because we had any Green choices that upped the cost.

Expected Water Efficiency points:  9 out of a possible 15.

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