Stop Reading the Full Code: What GC‘s Actually Need to Care About

National Resources 

These three sites cover most GC lighting code questions nationwide:

ICC – Code Adoption Maps(Find which IECC version each state adopts)：https://www.iccsafe.org/adoptions/

U.S. DOE – Building Energy Codes (Confirm adoption paths: IECC vs ASHRAE 90.1)：https://www.energycodes.gov/state-portal

California Energy Commission (CEC) – Official Title 24 Support：https://www.energy.ca.gov/programs-and-topics/programs/building-energy-efficiency-standards/energy-code-support-center-5

The 20% GCs Must Care About

Lighting Power / Energy Limits (Directly Impacts Fixture Selection)

Every one of these codes limits how much lighting power a space is allowed to use.

What GCs actually need to watch:

• Space type–based power limits (LPD or wattage allowances)

• Total fixture wattage after substitutions

• Changes made during value engineering or procurement

Why this matters:
A lighting layout that was code-compliant on drawings can become non-compliant after fixture substitutions, even if the new fixtures “look similar”.

Practical Differences GCs Should Know

IECC (Most States)

• Focuses on power limits and basic controls

• Relatively standardized

• Easier to verify quickly

ASHRAE 90.1 (Commercial Projects)

• Often used as an IECC alternative

• Common in office, retail, and industrial projects

• Well understood by inspectors

Title 24 (California)

• Much stricter control requirements

• Heavier emphasis on dimming and sensors

• Fixture and driver compatibility must be considered from day one

A GC’s 6-Question Lighting Code Checklist (Save This)

Before approving or purchasing lighting, ask:

1. Which code governs this project—IECC, ASHRAE 90.1, or Title 24?

2. Does this space type have a lighting power limit?

3. Are occupancy sensors or automatic shutoff required?

4. Do the fixtures and drivers support the required control method?

5. Are there state or city-level amendments?

6. Is all of this clearly documented in submittals and specs?

If you can answer these six questions, most lighting code risks are already under control.

Final Takeaway for GCs

IECC, ASHRAE 90.1, and Title 24 are not design guides.
They are risk-management tools.

As a GC, your goal is not to design lighting—it’s to:

• Avoid failed inspections

• Prevent late-stage rework

• Keep procurement aligned with compliance

• Protect your schedule and budget

You don’t need to know 100% of the code. You only need to control the 20% that actually affects buying, installing, and passing inspection.