Green Building Codes and Standards
What this domain covers
This domain tests how the layers of regulation fit together: federal law, state codes such as CALGreen, model codes and supplements such as the Uniform Plumbing Code and the IAPMO Green Plumbing and Mechanical Code Supplement, and voluntary rating systems such as LEED and the National Green Building Standard.
Core rules
- A code is enforceable law adopted by a jurisdiction; a standard is a technical document referenced by a code; a rating system is voluntary and awards points. Many questions turn on this distinction alone.
- CALGreen is mandatory statewide in California, with voluntary Tier 1 and Tier 2 reach provisions layered above the mandatory measures.
- LEED v4.1 Building Design and Construction sets an indoor water use reduction prerequisite of 20 percent and awards credit in steps from 25 percent up to 50 percent, plus separate credits for outdoor water use, cooling tower water use, and water metering.
- ASHRAE 189.1, the IgCC, and ICC 700 each contain water and energy provisions that apply where a jurisdiction has adopted them.
- Alternative materials and methods require approval from the authority having jurisdiction, supported by substantiating test data, before installation.
Worked example
A designer calculates a 24 percent indoor water reduction against the EPAct baseline. The LEED prerequisite of 20 percent is satisfied, but the first credit threshold of 25 percent is not reached. The project therefore earns zero points in that water efficiency credit even though the design clearly outperforms the plumbing code minimum.
Traps
Quoting a LEED credit threshold as if it were the legal minimum; forgetting that CALGreen applies statewide while LEED is project-driven and voluntary; assuming a WaterSense label equals bare code compliance when it exceeds it; chasing optional points while missing a prerequisite, which blocks the credit entirely.