Home Addition Title 24 Energy Reports

Who Needs a Home Addition Title 24 Report

Homeowners, contractors, architects, and developers undertaking home addition projects in California typically need a Title 24 report as part of the permit process. Title 24 is a statewide California energy code. Home addition projects follow the same statewide standards; the exact requirements depend on your project's scope and address, which we model in CEC-approved compliance software.

If you are not sure your project qualifies, start with do I need Title 24 for an addition? and our home addition Title 24 checklist.

What Triggers Title 24 on an Addition

The Energy Code (Title 24, Part 6) applies to additions because they increase the conditioned floor area of the home. Typical triggers include:

• Ground-floor room additions such as bedrooms, family rooms and primary suites
• Second-story additions over an existing home or garage
• Sunrooms and enclosed patios that will be heated or cooled
• Kitchen or bathroom expansions that push out exterior walls
• Additions combined with alterations, such as new HVAC equipment or replacement windows in the existing house

Small or cosmetic work may not need a report; the building department decides. See when Title 24 is required for the common triggers and exceptions.

How the Energy Model Treats an Addition

Additions can comply prescriptively (each listed requirement is met) or through the performance method, which most additions use. With performance, the addition is modeled in CEC-approved software and compared with a code-defined standard design. There are two common approaches:

• Addition alone — only the new space is modeled. This is simple, but the new work must stand on its own.
• Existing plus addition — the existing home and the addition are modeled together. Improvements to the existing house, such as new windows, attic insulation or a more efficient heat pump, can offset features of the addition that would otherwise fall short.

Either way, the model looks at wall, roof and floor insulation, window area and performance, heating and cooling equipment and duct location, water heating, ventilation and lighting. Glazing is a frequent pinch point on additions with large windows or sliding doors — see home addition window requirements and home addition HVAC requirements. Whether solar applies is covered on home addition solar requirements.

The climate zone for the address sets the energy budget, so the same addition can need different measures in different parts of the state. Look up yours on the California climate zones page. The full list of what is checked is on home addition Title 24 requirements, and the method is explained in Title 24 calculations.

What We Need

• Architectural plans (PDF) — floor plans showing existing and new areas, elevations, sections and a window schedule
• Project address (this sets the climate zone)
• Scope of work, including any changes to the existing house and HVAC
• Contact information
• Any plan-check comments (if available)

See documents needed for a home addition for more detail.

Pricing

• ADU — from $199
• Residential — from $245 (projects under 3,500 sq ft included, +$49 per 500 sq ft after)
• Multifamily — from $345

Single-family additions are ordered as a Residential report. The final price follows the square footage on the plans; if an adjustment is needed, we contact you before proceeding. See home addition Title 24 cost or the pricing page.

Turnaround

Standard turnaround: 2–3 business days. Rush (next business day): +$49 ADU / +$99 Residential / +$149 Multifamily. Super Rush (same day — typically within a few hours): +$150. Every report includes two revisions. See how long a Title 24 report takes.

What You'll Receive

• Permit-ready Title 24 energy report
• CF1R documentation (LMCC when applicable)
• CHEERS registration (when applicable)
• Professionally signed report
• PDF delivery, formatted for city submission
• Two revisions included

Common Plan-Check Issues

• Plans that do not clearly separate existing and new conditioned area
• Window schedules missing, or window sizes on the plans not matching the report
• No note on how the addition is heated and cooled — extended ducts, new equipment or a ductless unit
• Insulation shown on the sections that differs from the report

Our home addition plan-check corrections guide explains how to resolve these, and plan check comments covers how revisions work.

Sample Report

Your delivered package is a professionally signed, registry-registered PDF containing your CF1R (and LMCC where applicable) and all required compliance forms — formatted and ready to submit with your permit application. Prescriptive addition reports use a different CF1R form than performance reports; see what a CF1R is.

Frequently Asked Questions

Does a small addition need a Title 24 report?

Often, yes — any new conditioned space is covered by the Energy Code. Some very small additions can comply with a simpler prescriptive approach, but the building department decides what it needs to see.

Should the existing house be included in the model?

It is optional. Including it can help when the addition has a lot of glass or other features that are hard to meet alone, because upgrades to the existing home can offset them. We choose the approach that fits your scope.

Does a second-story addition need solar?

Additions are generally not treated the same as new homes for solar, but requirements depend on the scope and code cycle. The report determines what applies to your project.

Will a HERS rater need to visit?

Only if the report flags items for field verification, such as duct leakage testing when ducts are altered. See HERS rater vs Title 24 report.