Title 24 Alteration Reports — HVAC, Windows, Water Heater, and Remodel Compliance
Title 24 Calcs prepares Title 24 CF1R alteration reports for residential alterations throughout California. We cover HVAC replacement, window replacement, water heater replacement, lighting changes, and remodel projects that trigger energy compliance. Most alteration reports are ready within 1 to 2 business days starting at $250. See our cities service area for your location.
What Is a Title 24 Alteration?
An alteration changes existing energy systems in a California home. It covers insulation, windows, HVAC, water heating, or lighting — without adding conditioned floor area. Specifically, alterations differ from additions because they do not increase the size of the home. Furthermore, alterations follow different Title 24 compliance rules. Under the alteration path, only the systems within the permitted scope must meet current 2025 standards. The rest of the home stays as-is.
Specifically, the 2025 California Building Energy Efficiency Standards took effect on January 1, 2026. Consequently, all alteration permits submitted on or after that date must comply with the 2025 code. The 2025 code expanded HERS verification requirements for alterations. It also introduced a potential heat pump upgrade requirement for AC replacement projects. Read our 2025 Title 24 code changes guide for the full update summary.
Title 24 Alteration Report — key facts:
• Code: 2025 California Building Energy Efficiency Standards — effective January 1, 2026
• Alteration types: HVAC replacement, window replacement, water heater replacement, lighting, remodels
• Climate zones: All 16 California climate zones covered
• Starting price: $250 | Turnaround: 1 to 2 business days
• Includes: CF1R report, HERS registration, plan-sized PDFs, revision support
HVAC Replacement — Title 24 Alteration Report
Notably, HVAC replacement is one of the most common triggers for a Title 24 alteration report in California. Specifically, replacing any HVAC unit that requires a permit triggers Title 24 compliance documentation. Furthermore, the 2025 code expanded HERS verification requirements for HVAC replacement projects significantly.
Does AC Replacement Require a Heat Pump Under the 2025 Code?
Specifically, the 2025 code requires some AC replacement projects to upgrade to a heat pump. This applies instead of a like-for-like replacement. Specifically, this applies when the project triggers the performance path. It also applies when the home lacks a separate heating source. In practice, many simple AC replacements still qualify as like-for-like. Therefore, Title 24 Calcs confirms whether heat pump upgrading applies before starting your report.
What HVAC Alteration Reports Cover
Specifically, an HVAC replacement Title 24 alteration report covers these key elements:
- Equipment efficiency — the new system must meet minimum SEER2, EER2, HSPF2, or COP ratings for your climate zone
- Duct leakage — if new ductwork is part of the scope, duct leakage must stay below 5 percent of system airflow. A HERS Rater must verify this in the field
- Heat pump refrigerant charge — mandatory HERS verification in all 16 California climate zones under the 2025 code whenever a heat pump goes in
- Thermostat controls — setback thermostats and smart controls may apply depending on system type
- Fault indicator display — heat pump systems must include diagnostic displays confirmed by the HERS Rater
Read our Title 24 inspection guide for more on what HERS Raters verify. See our climate zones guide for efficiency requirements by zone.
Window Replacement — Title 24 Alteration Report
Additionally, window replacement that requires a permit triggers a Title 24 alteration report in California. The report confirms the new windows meet U-factor and SHGC requirements for your climate zone. U-factor and SHGC requirements vary significantly across California's 16 climate zones. Hot desert zones like Zone 15 have stricter solar heat gain limits than coastal zones.
The 75 Square Foot Window Rule
The 2025 code has a relaxed compliance threshold for small window replacements. Notably, replacements under 75 square feet qualify for U-factor 0.40 or less instead. Furthermore, glass-only or sash-only replacements without a new frame typically do not trigger Title 24. Therefore, Title 24 Calcs confirms which threshold applies before starting the report.
What Window Alteration Reports Cover
| Climate Zone | U-Factor Requirement | SHGC Requirement |
|---|---|---|
| Zone 6 — Coastal LA, coastal SD | ≤ 0.30 | ≤ 0.23 |
| Zone 7 — Chula Vista, Carlsbad | ≤ 0.30 | ≤ 0.23 |
| Zone 8 — Irvine, Anaheim | ≤ 0.30 | ≤ 0.23 |
| Zone 10 — Corona, Temecula, Fontana | ≤ 0.30 | ≤ 0.23 |
| Zone 12 — Sacramento | ≤ 0.30 | ≤ 0.25 |
| Zone 13 — Fresno | ≤ 0.30 | ≤ 0.23 |
| Zone 15 — Palm Springs, Palm Desert | ≤ 0.30 | ≤ 0.20 |
Window replacement does not typically trigger HERS field verification. However, when window and HVAC replacement share a permit, HERS testing may apply to the HVAC scope. Title 24 Calcs confirms what applies to your specific project.
Water Heater Replacement — Title 24 Alteration Report
Water heater replacement triggers a Title 24 alteration report when it involves a change of equipment type. This is common when switching fuel types or upgrading to a heat pump. Switching to a heat pump water heater requires documenting the ventilation, electrical, and space provisions needed. The 2025 code places strong emphasis on heat pump water heaters as the preferred replacement option. Read our Title 24 water heater guide for a full breakdown of water heater types and requirements.
Heat Pump Water Heater Requirements
A heat pump water heater (HPWH) extracts heat from the surrounding air to heat water. It uses approximately 60 percent less energy than a standard electric resistance water heater. The 2025 code makes heat pump water heaters the prescriptive baseline for most new homes and many alteration projects. However, HPWHs have specific installation requirements that go into the Title 24 alteration report:
- Minimum space — HPWHs require a minimum of 700 cubic feet of surrounding air space to operate efficiently
- Ventilation — adequate ventilation to the installation space must go into the report
- Electrical panel capacity — HPWHs require a 240V circuit. The report documents panel capacity requirements
- Efficiency rating — the unit must meet the minimum Uniform Energy Factor (UEF) for your climate zone
Like-for-Like Water Heater Replacement
A like-for-like gas water heater replacement may not trigger a Title 24 report in some jurisdictions. However, the new unit must still meet minimum efficiency standards. However, some building departments require documentation regardless.
Lighting Alterations — Title 24 Requirements
Significant lighting changes in a California home may trigger a Title 24 alteration report. Adding new lighting circuits or replacing fixtures in large quantities can trigger compliance requirements. Installing new lighting controls as part of a permitted scope also applies. Furthermore, all new fixtures must meet JA8 high-efficacy standards under the 2025 code.
JA8 High-Efficacy Lighting Requirement
Specifically, JA8 is a California lighting standard requiring high-efficacy LED fixtures with controlled dimming capabilities. All new fixtures in habitable rooms, bathrooms, garages, and utility areas must meet JA8 standards. Notably, JA8 fixtures are widely available from most major lighting brands. Therefore, Title 24 Calcs specifies the JA8 requirement on every applicable alteration report.
When Does a Lighting Change Not Trigger Title 24?
Simply replacing a bulb or swapping a like-for-like fixture typically does not trigger Title 24. However, new wiring, new circuits, or a significant increase in fixtures may trigger Title 24. In practice, confirm with your building department first. Additionally, we can confirm whether your specific lighting scope triggers a report.
CF1R, CF2R, and CF3R for Residential Alterations
Residential alterations follow the same three-certificate system as all California residential construction. The CF1R is the design-phase compliance document submitted at plan check. After installation, the CF2R confirms each system went in correctly. A certified HERS Rater then signs the CF3R after field verification where applicable.
| CF1R Certificate of Compliance. Title 24 Calcs prepares this. Submitted with the alteration permit application at plan check. | CF2R Certificate of Installation. The installing contractor signs this for each energy system after installation — HVAC, windows, water heater, or lighting. | CF3R Certificate of Verification. A certified HERS Rater signs this after verifying duct leakage and heat pump refrigerant charge where applicable. |
HERS Testing for Residential Alterations
Furthermore, HERS testing applies to alteration projects when the scope includes new HVAC equipment or new ductwork. Specifically, a certified HERS Rater visits after installation and verifies that systems perform as the CF1R specifies. Moreover, your building department requires this verification before issuing a certificate of occupancy.
HERS Measures That Apply to Alterations
- Duct leakage testing — applies when new ductwork goes in. Systems must leak less than 5 percent of system airflow.
- Heat pump refrigerant charge verification — now mandatory in all 16 California climate zones whenever a heat pump is part of the alteration scope. This is a new requirement under the 2025 code.
- Fault indicator display — heat pump systems must include diagnostic displays confirmed by the HERS Rater.
When HERS Testing Does Not Apply to Alterations
Notably, not all alteration projects require HERS testing. Window-only replacement projects typically have no HERS measures. Like-for-like water heater replacements typically have no HERS measures. Lighting-only alterations have no HERS measures. Consequently, the contractor completes the CF2R and no HERS Rater visit applies.
The California Energy Commission maintains the official list of approved HERS providers. See our Title 24 inspection guide for more on the HERS verification process.
Alteration Requirements by Climate Zone
HVAC efficiency requirements, window minimums, and insulation values all vary by climate zone. Therefore, Title 24 Calcs confirms your exact zone by project address before starting any alteration report. In practice, using the wrong climate zone is the most common cause of plan check corrections.
We serve alteration projects across all California climate zones. Key cities we cover include Irvine, Anaheim, Corona, and Temecula. Additionally, we serve Murrieta, Fontana, Rancho Cucamonga, and Ontario. We also cover San Bernardino, Sacramento, and Fresno. Additionally, we serve Chula Vista, Carlsbad, Palm Springs, and Palm Desert. See our climate zones guide and cities service area for all locations.
Frequently Asked Questions — Title 24 Alteration Reports
Does HVAC replacement need a Title 24 report?
Yes. Specifically, HVAC replacement that requires a permit typically triggers a Title 24 alteration report. A HERS Rater must also verify duct leakage and refrigerant charge. This must happen before the building department issues a certificate of occupancy.
Does AC replacement require upgrading to a heat pump?
Under certain conditions yes. The 2025 code requires some single-family AC replacement projects to upgrade to a heat pump. However, many simple like-for-like replacements still qualify. Therefore, Title 24 Calcs confirms before starting your report.
Does window replacement need a Title 24 report?
Yes when a permit applies. New windows must meet the 2025 U-factor minimums for your climate zone. Notably, replacements under 75 square feet qualify for a relaxed U-factor of 0.40 or less. Moreover, glass-only or sash-only replacements without a new frame typically do not trigger Title 24.
Does water heater replacement trigger a Title 24 report?
In practice, it depends on the scope. Switching to a heat pump water heater typically triggers a Title 24 alteration report. This is because of the ventilation and electrical documentation required. A like-for-like gas replacement may not trigger a report. Therefore, Title 24 Calcs confirms before starting your report.
How much does a Title 24 alteration report cost?
Pricing starts at $250. This includes the CF1R, HERS registration, plan-sized PDFs, and revision support. See our pricing page for current rates.
How long does a Title 24 alteration report take?
Most alteration reports are ready within 1 to 2 business days. Furthermore, rush options are available for urgent submittals.
What information do I need to provide?
For HVAC: equipment type, efficiency ratings, duct configuration, and project address. For windows: window schedule with U-factor and SHGC values. Water heater projects need equipment type, efficiency rating, and project address. In practice, more complete information means faster delivery.