It seems that for projects with small amounts of landscape areas, which many Homes: Midrise projects would be, the performance path doesn't seem to make sense.
In my case, I have a project with 142 occupants in 65 dwelling units in a downtown location on a near zero lot line. The project will potentially have 500-1000 sqft of landscaping. Based on the Performance Path method, the baseline Outdoor Water Use for the building would be roughly 3000 gallons / month, whereas the baseline Indoor Water Use is 214,000 gallons. Even if we were to include xeriscaping on this project we would only see an additional 1.5% reduction to our overall monthly water savings, which isn't even close to achieving an additional 0.5 points.
Whereas if we follow the prescriptive path, we can achieve 4 points by simply not including turf grass and using primarily native/ adapted plants. However, you make the Water section out of 10 instead of 12.
Am I reading this correctly? Are small landscaped projects penalized for reducing outdoor water requirements?
Ian Johnson
Senior DirectorLinnean Solutions
LEEDuser Expert
2 thumbs up
August 6, 2017 - 10:42 am
Tim,
I assume you are using the EPA Water Budget Tool? There shouldn't be a penalty for smaller spaces as the savings are calculated based on planting type and not the total landscaped area.
To earn the most points and you'll need to install plantings with a "low" water demand.(See the "Water Demand" Column in the online Water Budget Tool. When using low water demand plantings, the WBT will indicate savings from the baseline. Using "high" or "medium" water demand plantings makes it significantly harder to show water savings.
Yes the point threshold for the Prescriptive Path is 10 Points (6 indoor, 4 outdoor) vs 12 for the Performance Path.
Tim Nabholz
Associate - SustainabilityIntegral Group
9 thumbs up
August 23, 2017 - 1:54 pm
Hi Ian,
Thanks for your reply. In regards to your question, I have been using the Water Budget Tool provided by the EPA. Within the tool, you need to enter the landscaped area in order to determine the baseline. As such, because we have such a small landscaped area, our baseline water usage for the building is very small. Because it is so small, even if we were to reduce all outdoor water usage for the building, we still would see an additional 0 points under the Performance Path method as the indoor water use is 70+ times as much as the outdoor baseline.
Am I missing something?
Ian Johnson
Senior DirectorLinnean Solutions
LEEDuser Expert
2 thumbs up
August 28, 2017 - 9:50 am
You probably aren't missing anything, cases like yours are times when the Performance Path probably doesn't make the most sense, and you'll earn more points using the Prescriptive Path.