Short answer: Title 24 calculations are the energy calculations that show a California building design meets Part 6 of Title 24, the state Energy Code. For most homes and ADUs, the design is modeled in CEC-approved compliance software and compared with a code-defined "standard design." If the proposed building uses no more energy than that standard design, it complies, and the results are printed on the compliance forms submitted with your permit.
What Are Title 24 Calculations?
Title 24 calculations (also called Title 24 energy calculations) are the analysis an energy consultant runs to prove a project meets the California Energy Code. The inputs come from your plans: the size and orientation of the building, its walls, roof and floors, its windows, and its heating, cooling and water-heating equipment. The output is a compliance document — for most homes and ADUs the CF1R — that the building department reviews during plan check.
The calculations are the working part of a Title 24 report. The report is the finished, signed document; the calculations are what produce its results.
When Title 24 Calculations Are Required
Most building departments require energy calculations for new homes, ADUs, additions, garage conversions and many alterations, such as HVAC changeouts and window replacements. Small or cosmetic work may not need them, and the building department makes the final call. See when Title 24 is required for common triggers and exceptions.
What Information the Calculations Use
An energy model is only as accurate as the plans behind it. This table shows the main inputs and where each one usually comes from.
| Input | Where it comes from on the plans |
|---|---|
| Project address and climate zone | Title sheet or site plan; the climate zone is set by the address/ZIP |
| Conditioned floor area | Floor plans, dimensioned rooms and area calculations |
| Building orientation | Site plan with a north arrow |
| Wall, roof and floor assemblies | Building sections, wall sections and construction notes |
| Window and glazed door sizes and ratings | Window schedule and elevations |
| Heating and cooling equipment | Mechanical plan or equipment notes (type and efficiency) |
| Duct location | Mechanical plan or sections (attic, conditioned space, crawlspace) |
| Water heater type | Plumbing notes or equipment schedule |
| Solar PV and battery, if any | Electrical or solar plan sheets |
If something is missing, we either ask for it or note a reasonable assumption that must match what is built. See what documents to upload and what affects your report.
Performance vs Prescriptive Calculations
The Energy Code offers two ways to comply.
- Prescriptive: every component meets a listed requirement for your climate zone. There is little flexibility — if one item falls short, the project does not comply by this path. It is common for simple alterations.
- Performance: the whole building is modeled, and stronger features in one area can offset weaker ones in another. Most new homes, ADUs and additions use this method because it gives designers more freedom.
Mandatory measures apply under either approach and cannot be traded away.
The standard design comparison
Under the performance method, the software builds two versions of your project. The proposed design is your building as drawn. The standard design is the same building, with the same size, shape and climate zone, but built to the prescriptive requirements. The software estimates the energy each would use over a year. If the proposed design uses no more than the standard design, it passes. If it uses more, the consultant looks at options such as better windows, more insulation, more efficient equipment or moving ducts into conditioned space.
CEC-approved compliance software
Performance calculations must be run in compliance software approved by the California Energy Commission, such as CBECC. Approval attaches to the software, not to the consultant or the report. Title24Comply runs every energy model in CEC-approved compliance software for the code cycle that applies to your permit.
Title 24 Calculations vs HVAC Load Calculations
These are often confused, but they are not the same thing. Title 24 calculations show that the building as a whole meets the Energy Code. An HVAC load calculation (often done with ACCA Manual J) estimates how much heating and cooling a home needs so equipment can be sized correctly. Some building departments ask for both. A Title 24 report does not replace a load calculation, and a load calculation does not show Energy Code compliance.
Project Types We Calculate
- Detached and attached ADUs, JADUs and garage conversions
- Single-family homes, including new construction and additions
- Low-rise multifamily buildings such as duplexes, triplexes and fourplexes
- Residential alterations, including HVAC and window replacements
- Commercial projects by custom quote
How Long Title 24 Calculations Take
Standard turnaround is 2–3 business days after we receive complete plans. A 24-hour rush option is available, and for urgent projects we offer a same-day Super Rush — contact us first. See turnaround times and rush service.
How the Calculations Fit Into Permitting
The compliance forms are submitted with your permit application. During plan check, the building department compares them with the plans. If the reviewer finds a mismatch — a different window size, a changed water heater — you may get a correction comment and the calculations are updated. Two revisions are included with every Title24Comply report. See plan check comments. After construction, the building inspector and, where required, a HERS rater verify the installed features against the report.
What You Receive
You receive a permit-ready PDF by email: the CF1R for single-family homes and ADUs, or the LMCC for low-rise multifamily. Where the project requires it, the report is registered with the CHEERS data registry so your HERS rater and building department can access it.
How to Order
Choose your report type, enter project details, upload your plans as a PDF and pay securely online — it takes under five minutes. Pricing starts at $199 for ADUs, $245 for single-family residential and $345 per building for multifamily. See pricing and order.
Frequently Asked Questions
Are Title 24 calculations the same as a Title 24 report?
Closely related. The calculations are the energy modeling; the report is the signed set of compliance forms that presents the results for your permit.
Can I use the prescriptive method instead of energy modeling?
Sometimes, especially for simple alterations. For new homes, ADUs and most additions, the performance method is usually more practical because it allows trade-offs between building features.
Do Title 24 calculations size my HVAC system?
No. Equipment sizing comes from a separate load calculation, such as Manual J. The Title 24 calculations use the equipment you have selected and check that the building complies with the Energy Code.
Can I order calculations from preliminary plans?
Yes, if the key information is shown. Changes later may require an update. See preliminary plans and what happens if plans change.
Does my climate zone affect the calculations?
Yes. The climate zone sets the weather data and the standard design your building is compared with. Find yours on the climate zone map.
