Title 24 Calculations: Methods, Forms, and Costs

Title 24 calculations are the energy compliance reports California requires before a building department will issue a permit for nearly any project involving heated or cooled space. They document how your design meets Part 6 of the California Building Standards Code, which sets efficiency requirements for insulation, HVAC equipment, water heaters, windows, lighting, and more. The California Energy Commission updates these standards every three years, and the current 2025 Energy Code applies to all permit applications filed on or after January 1, 2026.1California Energy Commission. 2025 Building Energy Efficiency Standards For a typical new single-family home, the full compliance package (energy report, HERS registry fees, and field testing) generally runs $500 to $1,000 before permit fees.

When You Need Title 24 Calculations

If your project involves conditioned space, meaning any area heated or cooled for human comfort, the energy code applies. That covers new homes, offices, warehouses, retail, and apartments. Even unconditioned buildings have to meet the lighting requirements.2California Energy Commission. 2022 Building Energy Efficiency Standards

Additions that expand conditioned floor area or change the building envelope trigger compliance too. So do common alterations: replacing windows, upgrading an HVAC system, swapping a water heater, or reroofing with a material that changes solar reflectance. The depth of the required calculations scales with the work. A water heater swap may need only a prescriptive alteration form. A whole-house remodel or new commercial building needs full energy modeling.

A few narrow exemptions exist. Qualified historic buildings regulated under the California Historical Building Code are exempt where compliance would alter historic character, though any non-historic lighting still has to meet current standards. Local building departments can also exempt temporary structures, temporary lighting in unconditioned buildings, and structures built in response to a natural disaster, with the exemption expiring when the temporary permit does. Healthcare facilities in Occupancy Groups I-3 and I-4 are excluded.2California Energy Commission. 2022 Building Energy Efficiency Standards Outside those, expect to need a compliance report.

Prescriptive and Performance Compliance

There are two paths to prove your project meets the code. Which one your consultant uses affects cost, flexibility, and the design choices you have available.

Prescriptive Method

The prescriptive path is a checklist. Every component has to meet or exceed a specific value published in the code: wall insulation at a set R-value, windows under a set U-factor, air conditioner at a minimum SEER2 rating, and so on. Check every box and the project passes.

The advantage is simplicity, which is why it fits straightforward alterations and small additions of 1,000 square feet or less. The drawback is that there’s no room to compensate. If a single component falls short, the whole project fails this path. For designs with large window areas or unusual layouts, prescriptive compliance can also push up material costs.

Performance Method

The performance path uses approved energy modeling software to simulate the entire building. The software builds a virtual “standard design” version of your building that meets code and calculates an energy budget expressed as long-term system cost. Your proposed design has to stay within that budget.

The advantage is trade-offs. Larger windows with more solar heat gain can be offset by better insulation or a more efficient HVAC system. Most new homes and complex commercial projects use performance modeling because it lets designers balance construction cost, aesthetics, and efficiency. The tradeoff is more detailed input data and a consultant who understands the modeling well enough to work the offsets.3California Energy Commission. Building Energy Efficiency Standards

Performance reports have to be generated with software approved by the California Energy Commission for the 2025 code. The approved programs are CBECC 2025-2.1 (the CEC’s free public-domain software), EnergyPro 10.0 (commercial, all building types), IES VE Title 24 2025 1.0 (nonresidential new construction only), and Right-Energy Title 24 2025.2.0 (single-family residential new construction only). The compliance output is functionally equivalent across them.4California Energy Commission. 2025 Energy Code Compliance Software

What Your Consultant Needs From You

The accuracy of the calculations depends on the input data. Missing or wrong values produce a model that fails HERS verification in the field, which costs time and money to fix after construction has started. Before your energy consultant can produce a compliance report, gather:

  • Floor plans with exact square footage of every conditioned and unconditioned space, wall heights, and room orientations relative to north.
  • A window schedule listing the U-factor and Solar Heat Gain Coefficient for every window and glass door. Both values appear on the NFRC label attached to the product.
  • HVAC specifications: make, model, and efficiency ratings for all heating and cooling equipment.
  • Water heater details, including type (heat pump, gas, electric resistance), capacity, and efficiency rating. If you’re installing gas in new construction, you’ll also need to document the heat-pump-ready infrastructure.
  • Roofing materials with solar reflectance and thermal emittance values (often given as a Solar Reflectance Index or cool roof rating).
  • Insulation R-values for walls, ceilings, floors, and ducts.
  • Lighting fixture types, wattages, and control strategies, especially for nonresidential work.

Mandatory Measures and the 2025 Code Baseline

Regardless of which compliance path you use, mandatory measures set a floor you can’t trade away by over-performing elsewhere. They include minimum insulation R-values, air sealing at joints and penetrations, occupancy sensors and automatic shut-offs in specified rooms, minimum equipment efficiencies (SEER2 for cooling, AFUE for gas heating, HSPF2 for heat pumps), and cool roof requirements. Inspectors verify them by checking certification labels, measuring insulation, and confirming installation of air barriers and lighting controls.3California Energy Commission. Building Energy Efficiency Standards

The 2025 code layered several new baselines on top of that floor, and these are the ones most likely to shape the numbers in your report:

  • A solar photovoltaic system is required on all newly constructed buildings. Projects that qualify for an exception (very limited roof area, roofs that can’t structurally support panels, or a required system under 4 kW) still have to meet solar-ready requirements.5California Energy Commission. Solar PV, Solar Ready, Battery Energy Storage System (BESS)
  • Battery energy storage is required for newly constructed nonresidential buildings that must install solar. Residential buildings that don’t install a battery must at least meet battery-ready requirements.6California Energy Commission. 2025 Nonresidential Battery Energy Storage System (BESS)
  • Heat pump water heaters are the prescriptive baseline for all residential construction. If you install gas or propane instead, you have to use the performance path and offset the energy penalty elsewhere. You also have to install a dedicated 240-volt circuit and a space that can accommodate a future heat pump unit.

Forms, HERS Testing, and Final Approval

Compliance runs through three forms tied to three stages of the build:

  • The CF1R (Certificate of Compliance) is the energy calculation report itself. It’s generated from the software and submitted with your permit application.
  • The CF2R (Certificate of Installation) is completed by the installing contractor to confirm that insulation, ducts, windows, and other components were installed as specified in the CF1R.
  • The CF3R (Certificate of Verification) is completed by a third-party HERS rater after field testing confirms the finished building matches the approved plans.

For residential projects using the performance path, the CF1R has to be uploaded to a state-approved HERS registry such as CHEERS or CalCERTS. That creates a permanent record accessible to building inspectors, HERS raters, and future owners.7California Energy Commission. 2025 Energy Code Compliance Documents – Forms for Single Family Residential

After construction, a HERS rater performs diagnostic testing on site. Common tests include duct leakage, refrigerant charge, fan airflow, and building envelope air leakage. Results go into the registry and the CF3R issues on a successful pass. Your local building department needs completed CF2R and CF3R forms before it will issue a final certificate of occupancy.

What Title 24 Compliance Costs

The compliance report is the most predictable line item. For a standard residential project under 3,000 square feet, energy consultants typically charge $200 to $400 for a complete Title 24 report. Larger or more complex homes run $400 and up. Accessory dwelling units and simple additions often come in under $250. Rush service usually adds $75 to $100.

Beyond the report, budget for:

  • HERS registry upload fees, around $7 per performance plan upload through CHEERS, with no charge for revisions that replace an existing file within the same project.8CHEERS. Pricing
  • HERS field testing, which typically starts around $200 for basic diagnostic testing on a single-family home. Costs go up for projects requiring multiple tests or retesting.
  • Permit and plan check fees, which vary by jurisdiction and are usually calculated on construction valuation. Your local building department sets its own schedule.

The total compliance cost for a typical new single-family home, from energy report through HERS testing and registry fees, generally lands in the $500 to $1,000 range before permit fees. That’s a small share of overall construction cost, but it’s worth planning for upfront rather than scrambling when the building department holds your permit.

What Happens If Field Testing Fails

When a HERS rater finds a failure during diagnostic testing, the failed item has to be corrected and the building retested. You keep fixing and retesting until it passes. For a single-family home, that loop is painful but contained.

For subdivisions and multifamily projects using sample testing, the stakes compound. If the first randomly selected unit fails, the rater tests a second unit from the same group. If the second unit passes, the first failure is treated as isolated and the remaining untested units get their CF3R documents. If the second unit also fails, every untested unit in the group has to be individually tested. On a 20-unit project, one duct-sealing shortcut can turn into weeks of delay and thousands in retesting fees.

Most HERS failures come back to workmanship: duct connections that weren’t sealed, insulation that was compressed or left with gaps, HVAC installed without verifying refrigerant charge. These are installation problems, not design problems, and they’re preventable when the crew treats the compliance report as the spec rather than a suggestion.