Conduct a preliminary cost-benefit analysis to determine the first cost and life cycle payback. Most teams use LEED point thresholds as a way to frame the analysis. For example, what is the cost and the payback of meeting the 2.5% threshold?
Start by reducing the building’s energy load. The smaller the load, the less renewable energy you have to generate to meet the credit thresholds, which saves money and might expand the options you can use.
This credit involves the use of an Environmental Impact Calculator & USGBC Credit Calculator which will be available for use by projects participating in the pilot. USGBC has not made it available for public viewing. To access the calculators, register your project for the credit (see Resources).
Even one piece of equipment can tip your calculations to compliance or noncompliance. Use the calculator in the LEED Online submittal template to run calculations from the beginning of HVAC system selection (note that your project has to be registered through LEED Online to download those forms). This gives a sense of how far from compliance a system may be; teams then get a better idea of how significant a change may be required. Note that annual leakage and end-of-life refrigerant loss rates are set to defaults but can be edited if needed.
If your project building is connected to a district chilled-water system, you have to include all the chillers in that system in the calculations, even if they are outside your project’s scope or control. As a rule of thumb, if the system is serving your LEED project it should be included in calculations, whether it is within your project scope of work or not.
If your project has no cooling system or uses a system without refrigerants, you can achieve the credit through Option 1 (“do not use refrigerants”). Document your credit compliance path with appropriate supporting documents by completing the submittal template and providing cut sheets or other confirmation of the system type.
Establish preliminary goals for water-use reduction. Consider setting water-reduction goals higher than the 30% reduction required by this credit, and aim for a reduction greater than 40% or higher for exemplary performance under IDc1. You are likely to need rainwater or graywater
You can earn an Exemplary Performance point through IDc1 for a 40% reduction. To help you meet this threshold, you can include appliance and process water in the calculations, even though that’s not allowed for the standard credit calculations.
