BoK Energy Design

§ 09 · JOURNAL

Field notes from the drafting table.

Essays on California Title 24, the code cycle that runs every new home in the state. Written for architects, builders, and owners who want to understand what the CF1R actually says and why the 2025 updates matter.

SHEET09 / JOURNALPROJECTBoK Energy DesignDATE04/23/26SCALE1:1REV01

ENTRIES

05

AUTHOR

Bo Kellett

CODE CYCLE

2025 · PART 6

LAST UPDATED

APRIL 15, 2026

§ 09.A · LATEST ENTRY

№ 01

SHEET 09.A

FEATURED

2025 Code · Compliance

HERS is now ECC

HERS is now ECC: what the 2025 rename means for your project

California's HERS program has been renamed ECC, the Energy Code Compliance program. The acronym on the CF1R changes. Almost nothing else does. Here's what to tell your architect, your homeowner, and your plan-check reviewer.

READ THE ENTRY

§ 09.B · CATALOG

04 ENTRIES

№ 02
· Compliance· Design

Performance vs prescriptive Title 24: which path is right for your home?

Two compliance paths, one permit. The prescriptive method checks a list. The performance method runs a computer model. Here is how each one actually works, when each makes sense, and why our office runs performance for every project.

5 min read
№ 03
· Climate Zones· Fundamentals

California's 16 climate zones, and why yours matters

California is the only state that writes its energy code against sixteen distinct climate zones. A wall assembly that passes in San Francisco will fail in Palm Springs. A field guide to all sixteen: how they're drawn, what each one expects, and how to find yours.

5 min read
№ 04
· CF1R· Fundamentals

What a CF1R actually is, and how to read one

CF1R, CF2R, CF3R: three letters that show up on every California residential project and confuse almost everyone. Here's what each form is for, what fields the CF1R actually contains, and what a plan-check reviewer is looking at when they open it.

6 min read
№ 05
· 2025 Code· Compliance

2025 Title 24 changes architects need to know

The 2025 California Energy Code took effect January 1, 2026. Heat pumps are the new baseline. Battery storage gets real credit. Peak Cooling is a new metric on new construction. LSCe replaces EDR. Here is the short, practical list.

6 min read

§ 09 · NEXT SHEET

Reading is research. A permit-ready CF1R is the deliverable.

Flat $300 per dwelling. 1–3 business days. Plan-check errors on us. Email the plans and we start the same day.

START A PROJECT →TITLE 24 / 101