Skip to content
CrossBeamStart a pre-check

Building Code Reference

Got a Title 24 150.0 correction?

Energy code requirements

For builders in California, Greater Seattle, the Las Vegas area, the Denver area and Kansas City · CrossBeam Permits

What this code requires, how to fix it, and how cities and counties review it

What this code requires

Title 24 Part 6 Section 150.0 is the California Energy Code section that sets mandatory performance minimums for insulation, windows, HVAC equipment, lighting, solar PV, and air sealing in residential construction. It covers both new homes and permitted alterations. Compliance is documented on CF1R forms, which must match the specifications shown on submitted plans. Most single-family, ADU, and multi-unit residential permits get flagged on Section 150.0 when the plans show values that don't match the CF1R calculations, or when the conditioned floor area is stated incorrectly.

How to fix it

  1. Pull the CF1R and lay it next to the plan set

    Get the current CF1R output from whoever ran the Title 24 compliance calculation (usually the mechanical engineer or a Title 24 consultant). Open it alongside the architectural plans and mechanical schedule. You're looking for three sets of numbers to match: insulation R-values, window U-factor and SHGC, and conditioned floor area. These must be identical across all three documents. If your CF1R was run on a prior version of the plans, that's the source of the correction.

  2. Verify conditioned floor area matches on all documents

    The conditioned floor area on the CF1R must match the square footage shown on the floor plan and noted in the general notes. Pull the actual square footage off the floor plan (not from a prior permit or a contractor estimate). If they don't match, the Title 24 consultant needs to rerun the compliance calculation with the corrected area before you resubmit. A 10% difference in floor area can change whether the project passes prescriptive compliance.

  3. Check insulation values on plans against CF1R

    On the architectural plans, find the insulation schedule or general notes. Common locations: wall section details, the building envelope summary table, or the energy notes sheet. Confirm that wall insulation R-value, ceiling/roof insulation R-value, and floor insulation R-value (if applicable) match the CF1R exactly. For prescriptive compliance, verify your proposed R-values for walls and ceilings against the current Climate Zone table in Title 24 Part 6. Climate Zone minimums are edition-specific — check the 2025 Residential Compliance Manual or your jurisdiction's adopted edition for the exact values before finalizing the CF1R. If you're using a different climate zone or a performance path, pull the CF1R output for the actual required values.

  4. Confirm window U-factor and SHGC on plans match CF1R

    Find the window schedule on the architectural plans. Each window type should list the U-factor and SHGC (solar heat gain coefficient). These values must be equal to or better than (lower than) the values on the CF1R. If the CF1R specifies U-0.30/SHGC-0.25 and the window schedule says U-0.32, that's a correction. Ask the window manufacturer for a NFRC label spec sheet to confirm the actual product ratings, then update the window schedule accordingly.

  5. Check HVAC equipment efficiency ratings on mechanical schedule

    The mechanical schedule should list the specific equipment model numbers and their rated efficiencies: SEER2 for AC systems, AFUE for gas furnaces, HSPF2 for heat pumps. These ratings must meet or exceed what the CF1R specifies. Under the 2025 code cycle, minimum is generally SEER2 14.3 for AC in most zones. Look for the manufacturer's spec sheet if the schedule doesn't list the rating directly. The CF1R may also specify minimum duct insulation levels (R-6.0 is the mandatory minimum; the prescriptive package calls for R-8 in most climate zones).

  6. Add CF1R form to the plan set as a submitted document

    The CF1R form (Certificate of Compliance) must be included in the plan set as a submitted document. For prescriptive new construction it's the CF1R-NCB-01-E. For prescriptive alterations it's a CF1R-ALT form, such as CF1R-ALT-01-E. The form must be signed by the documentation author and the responsible designer, and it must show the ECC field verification requirements (formerly HERS). If your submission was missing this form or included an outdated version, include the current signed version with your resubmittal and note the change on the revision cloud.

  7. For ADU or addition projects, confirm new CF1R covers the addition

    Any new conditioned square footage attached to an existing building requires a CF1R covering the new area. This includes garage conversions to ADU, additions over 300 SF, and projects that add or replace the HVAC system. A common mistake is submitting plans for a 500 SF addition with a note that says "energy compliance per existing building" and no CF1R. That's an automatic correction. The Title 24 consultant needs to run a new calculation for the addition separately or for the whole house if the HVAC is being replaced.

  8. Resubmit with revision clouds and a response letter

    On the resubmitted plans, cloud all the sheets where values changed. If you updated the window schedule on A-5, cloud the changed rows. If you updated the energy notes, cloud those. Include a correction response letter listing each flagged item by number and explaining the change made. Plan-checkers handle dozens of resubmittals a day. Making it easy to find what changed is the fastest path to approval.

Take the Title 24 150.0 fix steps with you

All 8 steps in one email, so you have them on site instead of on this page.

Why you got flagged

The most common reason plan-checkers flag Section 150.0 is a mismatch between the CF1R energy compliance form and the actual plan sheets. The CF1R is generated by Title 24 compliance software (EnergyPro, CBECC-Res, or similar) and shows prescriptive values for wall insulation R-value, ceiling R-value, window U-factor, and SHGC. If your architectural plans show a different window U-factor or a different insulation depth than what's on the CF1R, expect a correction. This is the single most frequent Title 24 correction on residential projects in OC.

A second trigger is conditioned floor area. The CF1R calculates energy use based on a specific square footage. If your plans show 1,850 SF of conditioned space but the CF1R was run at 1,600 SF, the compliance calculation is wrong. Plan-checkers compare these numbers directly, and even a 10% discrepancy will get flagged. This is easy to miss if the mechanical engineer ran the CF1R from an early set of plans before the architect updated the floor plan.

HVAC system specs are another common source of corrections. Section 150.0 sets minimum efficiency ratings for furnaces (AFUE), air conditioners (SEER2), and heat pumps (HSPF2). If the mechanical plans specify equipment that doesn't meet those thresholds, or if the equipment listed on the CF1R doesn't match the equipment on the mechanical schedule, you'll get a correction. Duct location and sealing requirements under 150.0(m) also trip up projects where ducts are run through unconditioned attic space without proper insulation.

The fourth scenario is new additions and alterations. When you add conditioned square footage to an existing home, Section 150.0 applies to the new area. Some contractors incorrectly assume a small addition is exempt or can match the existing building's older standards. Any new conditioned space must meet the current code cycle standards, which means a fresh CF1R covering the addition is required.

The official code

California Energy Code Title 24 Part 6 - 2025 Building Energy Efficiency Standards

Read the source →

Common questions

Does Title 24 Section 150.0 apply to ADU projects?
Yes. Any new ADU or garage conversion to ADU must comply with the current adopted cycle of Title 24 Part 6, including Section 150.0. The CF1R must cover the entire conditioned area of the ADU, including any new HVAC equipment. If you're converting an existing garage with no prior CF1R on file, the Title 24 consultant runs the calculation for the new conditioned space. ADU projects in OC climate zones (primarily Zone 8 and Zone 9) have specific prescriptive values for insulation, windows, and mechanical equipment.
What is a CF1R and why does it need to match the plans?
The CF1R (Certificate of Compliance, Residential) is the output document from Title 24 compliance software that shows how your project meets the energy code. It lists the required insulation R-values, window performance specs, HVAC efficiency minimums, lighting requirements, and ECC verification items. Plan-checkers use it as the spec sheet against which they review the architectural, mechanical, and electrical plans. If any value on the plans doesn't match the CF1R, the correction is automatic. The CF1R must be rerun whenever the floor plan changes, the HVAC system changes, or the window specs change.
What climate zone is Anaheim and Orange County for Title 24?
Most of Orange County falls in Climate Zone 8, which covers coastal and near-coastal areas including Anaheim, Santa Ana, Fullerton, Garden Grove, and similar cities. Some inland OC cities near the hills may fall in Climate Zone 9. The climate zone affects the prescriptive R-values, window U-factor and SHGC requirements, and solar PV sizing. Your CF1R will specify the climate zone used in the calculation. If the zone on the CF1R doesn't match the project address, the calculation needs to be rerun.
My plans say insulation is per Title 24 compliance. Is that enough?
No. A note that says "insulation per Title 24 compliance" without specifying actual R-values is a common source of corrections. The plan-checker needs to see the actual required R-values called out on the plans so they can verify they match the CF1R without having to interpret a general note. Put the R-value directly on the insulation schedule, the wall section, or the energy notes sheet. Something like "R-19 batt + R-5 continuous at exterior walls" is clear; "energy code compliant" is not.
What HVAC efficiency does Title 24 require for a new AC system?
Under the 2025 California Energy Code (effective January 1, 2026), the minimum efficiency for new central air conditioning in most residential climate zones is SEER2 14.3 for split systems. For heat pumps the minimum is HSPF2 7.5. For gas furnaces, AFUE 80% is the federal minimum but the CF1R may specify the exact value required for your project. Performance-path calculations may specify different numbers. Always pull the CF1R for your specific project rather than relying on the general minimum, since equipment specs that match the CF1R are what plan-checkers verify.
Do duct systems need to meet Title 24 Section 150.0 requirements?
Yes. Section 150.0(m) covers duct insulation and sealing. Ducts in unconditioned space must be insulated to at least R-6.0, with R-8 in the prescriptive package for most climate zones. Ducts must also be sealed at all joints, connections, and penetrations. ECC verification (field testing by a certified ECC-Rater) is required for most new duct systems to confirm leakage rates meet the code. The CF1R will list the ECC measures required for your project. Missing duct insulation or sealing specs on the mechanical plans is a common Section 150.0 correction.

Related corrections

Check my plans for this →