Title 24 vs CALGreen: What Is the Difference?

The confusion comes from the naming

Title 24 is the California Building Standards Code as a whole, divided into numbered parts. Part 6 is the California Energy Code. Part 11 is the California Green Building Standards Code, universally called CALGreen.

So "Title 24 versus CALGreen" compares a whole code with one of its own parts. When a building department asks for "your Title 24" it means Part 6 energy documentation — that shorthand is where the muddle starts, and it is worth being precise about because the two parts ask for genuinely different things.

What each one is about

Part 6 is energy: the envelope, lighting, mechanical systems, water heating, and increasingly solar and storage. Its question is how much energy the building will use.

Part 11 is broader environmental performance: water efficiency and conservation, construction waste diversion, material selection and pollutant control, and indoor environmental quality. Its question is the building's wider footprint — including things Part 6 has no view on at all, like how much construction waste leaves the site.

They overlap least where people assume they overlap most. A building can be highly efficient under Part 6 and still have nothing to say about waste diversion or water fixtures.

CALGreen has mandatory measures and voluntary tiers

This is the structural difference that catches projects out. CALGreen contains mandatory measures that apply statewide, and above those it defines voluntary tiers of higher performance.

The tiers matter because a local jurisdiction can adopt one, turning what is voluntary statewide into a requirement locally. So the CALGreen scope for a given project depends on where it is in a way the Part 6 scope generally does not.

Separate documentation

Part 6 compliance produces the certificate families — CF1R and its relatives on residential work, the NRCC series on nonresidential. CALGreen compliance is documented separately, often on a jurisdiction's own checklist, and it is verified differently.

A complete energy submittal therefore does nothing to satisfy CALGreen, and a completed CALGreen checklist does nothing to satisfy Part 6. Projects that assume one covers the other are the ones held at plan check.

What changed in 2025 CALGreen

The 2025 edition of CALGreen took effect alongside the 2025 Energy Code: both apply to buildings whose permit application date is on or after 1 January 2026. Most of the mandatory changes, as the Building Standards Commission summarises them, concern electric vehicle charging and bicycle parking.

• New multifamily buildings. Where parking is unassigned or shared, 25 per cent of the spaces not already given a low-power Level 2 receptacle must now have a Level 2 charger, up from 10 per cent. Chargers may use J1772 or J3400 connectors, and an automatic load management system can reduce the electrical capacity required. Hotels and motels now have a section of their own: 40 per cent of spaces with low-power Level 2 receptacles and 25 per cent with Level 2 chargers.
• Existing multifamily, hotel and motel parking. Each parking space that is added or altered now needs a low-power Level 2 receptacle or a Level 2 charger, replacing the old percentage of EV capable spaces, with an exception for installing Level 1 receptacles.
• Bicycle parking. Measures that were voluntary became mandatory for new multifamily buildings, hotels and motels. On nonresidential projects, short-term spaces are now counted from expected peak daily visitors, and long-term spaces from tenant-occupants at 10 per cent rather than 5.
• Commercial EV charging. The nonresidential table now separates office and retail from other occupancies and requires more charging stations. Chargers must have J1772 or J3400 connectors, and a site with existing EV capable spaces must build those out before adding new ones.

For a new single-family home or an ADU, little moved. The Building Standards Commission's summary lists no change to the one- and two-family requirement, which is still a raceway and panel capacity for a future 40-ampere 208/240-volt circuit, marked EV CAPABLE, and ADUs without additional parking facilities are still excepted. A residential addition or alteration brings in CALGreen only where it increases conditioned area, volume or size, and then only within that area. EV chargers and Title 24 covers the charging rules in more detail.

One change ties the two parts closer together. CALGreen's energy definitions now use Long-term System Cost, the metric of the 2025 Energy Code, in place of the previously used TDV metric. The voluntary tiers moved too, mostly toward more EV provision on multifamily projects, which matters wherever a city has adopted a tier.

What this means practically

Ask the building department which parts apply to your scope, and treat them as two separate deliverables with two separate owners. Energy compliance is a modelling and documentation exercise; CALGreen is substantially a construction-practice and procurement exercise, and the people who can answer for it are often not the same people.

Common Title 24 Questions

1. What is Title 24?
2. Do I need a Title 24 report?
3. How much does a Title 24 report cost?
4. How long does a Title 24 report take?
5. What is included in a Title 24 report?
6. What plans do I need to upload?

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