The required savings can be achieved via any of the available water reduction strategies listed in the LEED Reference Guide, including alternative water sources.
This credit does require weekly tracking, so without weekly data from the utility the project would not be eligible for the credit, according to GBCI.
All meters must be recorded at least weekly during the performance period to earn this credit. You’ll want to be sure all your water meters are in place prior to the start of the performance period so that you’re able to meet the weekly meter-reading requirement.
This is the most complex part of the calculations. The interpretation referenced above identifies the U.S. EPA Stormwater Management Model (SWMM) and National Stormwater Calculator as appropriate compliance tools. If you’re not already familiar with these tools, expect to spend some time learning them, but they should help you to nail down the volume of stormwater managed by your green infrastructure.
LEED Interpretation #100001950 outlines updated protocol for calculating the total runoff. Generally you need to know the rainfall depth (mm) for the 95th percentile storm, the area of the impermeable spaces, and the runoff coefficient, which is described as “Small Storm Hydrology Method Runoff.” See the interpretation for more details.
USGBC’s calculator helps teams calculate the 95th percentile storm, but you first need to collect at least 10 years of historic rainfall data from the National Climatic Data Center and paste it into the USGBC calculator. The rainfall data will likely be in the format of daily rainfall amounts over historic years. So, expect to input a lot of data points into the calculator.
You’ll need to calculate (1) the volume of rainfall for the 95th percentile storm, (2) the total stormwater runoff from impermeable surfaces on your site, and (3) the volume of runoff that gets infiltrated or captured for reuse by your green infrastructure.
The most effective measure of a roofing material’s ability to reject solar heat is the solar reflectance index (SRI), a measure of the constructed surface’s ability to stay cool in the sun by reflecting solar radiation and emitting thermal radiation.
However, solar reflectance, or SR, is a better way to measure materials that have more thermal mass, including nonroof materials. SR is the fraction of solar energy that is reflected by a surface on a scale of 0 to 1. It doesn't factor in emissions of thermal radiation the way SRI does.
Only one option can be pursued. However, Option 3 is worth two points while the other options are each worth one point. Remember to also consider whether your project can earn exemplary performance for any of the available options.
No, the contractor does not need to document the maintenance of the equipment. Provide a total inventory of the contractor's equipment (this could be a list, copies of the manufacturer's info, or anything showing the type of equipment they use and power source. Of course, the inventory is just a snapshot in time. Ensure that substitutions are also electric.