Title 24 Energy Code and Your Remodel: What Triggers Compliance and How to Budget for It

By California Construction & Remodeling Experts | February 2026

The Code Nobody Explains Until It's Too Late

Here's a scene we see far too often. A homeowner in Los Angeles hires a contractor to remodel their kitchen. The design is finalized. The permit application is submitted. Then the city's plan checker sends back a correction notice with three words that derail the entire budget: "Title 24 compliance required."

Suddenly there's an energy consultant fee they didn't expect. Insulation upgrades they didn't budget for. A HERS inspection they've never heard of. And a window specification change that adds thousands to the project because the ones they already selected don't meet the U-factor requirement for Climate Zone 9.

This happens because most contractors treat Title 24 as something to deal with during plan check rather than something to plan for during design. That approach costs homeowners money, time, and trust.

At California Construction & Remodeling Experts, we build Title 24 compliance into every project estimate from day one. This article explains exactly what Title 24 is, when it applies to your remodel, what it costs, and how to budget for it so there are zero surprises between your first consultation and your final inspection.

📌 Key Takeaways: What You'll Learn in This Article

• When Title 24 Gets Triggered: The specific remodeling activities (window replacement, HVAC upgrades, additions, insulation changes) that activate energy code compliance.

• What HERS Testing Actually Is: A plain-language breakdown of the inspections your project may require, and what each one costs ($250–$1,500).

• Prescriptive vs. Performance: The two compliance pathways, when each one saves you money, and how to choose.

• 2026 Cost Benchmarks: Real Title 24 compliance costs for common Los Angeles remodeling projects ($1,500–$8,000+).

• The 2025 Code Update: What changed on January 1, 2026, including expanded heat pump requirements and updated envelope standards.

What Title 24 Actually Is (And Why It Applies to Remodels, Not Just New Construction)

Title 24 is Part 6 of the California Building Standards Code, officially called the Building Energy Efficiency Standards. It's written and maintained by the California Energy Commission (CEC), and it sets minimum energy performance requirements for every building in the state.

The critical thing most homeowners miss: Title 24 applies to alterations and additions to existing homes, not just new construction. If your remodel touches certain building systems, you must demonstrate that the affected components meet current energy code requirements before the city will issue your building permit.

The code is updated every three years. The most recent update, the 2025 Energy Code, took effect on January 1, 2026. Any permit application submitted on or after that date must comply with the 2025 standards. If your permit was submitted before that date, the previous 2022 code applies.

California has 16 climate zones, and Title 24 requirements vary by zone. Los Angeles, Beverly Hills, West Hollywood, and most of LA County fall in Climate Zone 9. Some foothill and valley communities may fall in adjacent zones. Your energy consultant will determine which zone applies to your specific property.

⚠️ Pro-Tip: The version of Title 24 that applies to your project is determined by the date your permit application is submitted, not the date your plans are completed or the date construction begins. If you're close to a code update deadline, timing your permit submission strategically can save thousands.

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The Five Remodeling Activities That Trigger Title 24 Compliance

Not every remodel triggers Title 24. Purely cosmetic work like painting, replacing cabinet hardware, or changing light fixtures to equivalent types generally does not. But any remodel that affects the building envelope, mechanical systems, or lighting in a significant way will trigger some level of compliance.

Here are the five most common triggers we see in Los Angeles residential projects.

Trigger 1: Window Replacement

Replacing windows is one of the most common Title 24 triggers in remodeling. When you install new windows, the replacement units must meet specific thermal performance ratings for your climate zone.

For Climate Zone 9 (most of LA County), the key metrics are:

U-factor: This measures how well a window prevents heat from escaping. Lower is better. The 2025 code requires a maximum U-factor of 0.30 for most residential window applications in this zone.

Solar Heat Gain Coefficient (SHGC): This measures how much solar radiation passes through the window. In cooling-dominated climates like Los Angeles, a lower SHGC helps reduce air conditioning loads. The 2025 code sets maximum SHGC values that vary by orientation and overhang conditions.

What this means in practice: the windows you select must carry a National Fenestration Rating Council (NFRC) label showing performance ratings that meet or exceed these values. If you fall in love with a window style that doesn't meet the numbers, you'll either need to choose a different product or compensate elsewhere in your project through the performance compliance pathway.

Trigger 2: HVAC System Replacement

If your remodel includes replacing your heating, cooling, or water heating system, the new equipment must meet current Title 24 efficiency standards. The 2025 code strongly encourages heat pump technology for both space conditioning and water heating.

For space heating and cooling, the code establishes energy budgets that assume heat pump performance as the baseline. If you choose a traditional gas furnace and air conditioner instead, you may need to compensate with higher efficiency in other areas (better insulation, better windows, solar panels) to meet the overall energy budget through performance compliance.

For water heating, the 2025 code similarly encourages heat pump water heaters. Traditional gas water heaters are still permitted, but the energy budget assumes electric heat pump performance, making compliance more challenging with gas equipment.

Any new or replacement HVAC installation also triggers mandatory HERS duct leakage testing to verify that your duct system doesn't exceed maximum allowed air leakage rates. Leaky ducts can reduce HVAC efficiency by up to 30%, and California requires independent verification that your system is properly sealed.

Trigger 3: Room Additions and ADUs

Any addition of conditioned (heated and cooled) space to your home triggers full Title 24 compliance for the new area. This includes room additions, bump-outs, enclosed patios, and Accessory Dwelling Units (ADUs).

The new space must meet all current energy requirements including insulation values, window specifications, lighting efficacy, and mechanical system efficiency. For additions above certain size thresholds, solar photovoltaic and battery storage requirements may also apply, though the 2025 code provides some flexibility depending on project size and site conditions.

Trigger 4: Insulation and Building Envelope Changes

If your remodel involves opening walls, replacing roofing, or otherwise modifying the building envelope (the physical barrier between conditioned interior space and the outside), the affected areas must be brought up to current insulation standards.

For Climate Zone 9, key prescriptive insulation requirements include:

Building Component	2025 Prescriptive R-Value	What It Means
Ceiling / Attic	R-38	Approximately 12 inches of fiberglass batt or equivalent
Exterior Walls (wood frame)	R-15 or R-21 (varies by method)	Cavity insulation in standard 2x4 or 2x6 framing
Raised Floor	R-19	Insulation between floor joists over crawl space
Slab Edge (heated slab)	R-7	Rigid foam at perimeter of heated concrete slabs

If your existing insulation is below these values in the areas being remodeled, bringing it up to code becomes part of your project scope and cost.

Trigger 5: Lighting Changes

Any new or replaced lighting must meet current Title 24 efficacy requirements. In practice, this means LED fixtures throughout. The 2025 code also includes requirements for lighting controls, including dimmers, occupancy sensors, or daylight-responsive controls depending on the application.

For most kitchen and bathroom remodels, the lighting component of Title 24 compliance is straightforward and doesn't add significant cost, since LED fixtures have become the standard regardless of code requirements. However, if your design includes specialty fixtures that use less efficient lamp types, compliance may require substitutions.

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HERS Testing: What It Is, What Gets Tested, and What It Costs

This is the section your contractor should be explaining during your first meeting and almost never does.

HERS stands for Home Energy Rating System. A HERS rater is an independent, third-party certified inspector who verifies that the energy-related components of your project were installed correctly and perform as designed. HERS raters are certified through providers like CalCERTS or CHEERS, and by law they cannot be employees of or have a financial interest in the builder or contractor whose work they're inspecting.

Think of the HERS rater as the energy code equivalent of a building inspector: an independent set of eyes confirming that what was designed on paper actually works in the field.

What Gets Tested

Depending on your project scope, one or more of the following HERS verifications may be required:

Duct leakage test. The rater pressurizes your duct system with a specialized device called a duct blaster and measures how much air is escaping through gaps, joints, and connections. This is the most commonly required HERS test for remodeling projects that involve HVAC work.

Refrigerant charge verification. The rater confirms that your air conditioning or heat pump system has the correct amount of refrigerant, which directly affects cooling efficiency and equipment lifespan.

Fan efficacy testing. The rater measures the airflow and wattage of your HVAC system's air handler to verify it meets minimum efficiency standards.

Quality Insulation Installation (QII). The rater inspects insulation before walls are closed up to confirm it's properly installed with no gaps, compression, or voids. This test must happen at a specific point during construction, before drywall is hung.

Whole-house mechanical ventilation airflow. For projects that include ventilation system modifications, the rater verifies that the system delivers adequate fresh air to meet indoor air quality requirements.

What It Costs

HERS Test	Typical Cost	When It's Required
Duct Leakage Test	$250 – $400	Any new or replacement HVAC with ductwork
Refrigerant Charge Verification	~$250	New split-system AC or heat pump installation
Quality Insulation Installation (QII)	~$350	Additions, ADUs, or significant envelope work
Blower Door (Building Leakage) Test	$400 – $600+	Some additions and new construction
Full HERS Testing Package	$700 – $1,500	Projects with multiple trigger points

⚠️ Pro-Tip: HERS testing must be scheduled at specific construction milestones. QII must happen before drywall. Duct testing must happen after HVAC is installed but before final inspection. A contractor who understands these timing windows builds them into the construction schedule. One who doesn't will cause delays when the HERS rater isn't available at the right moment.

It's also important to know that as the homeowner, you have the right to hire your own HERS rater independently of your contractor. While many contractors work with preferred raters, an independent rater ensures there's no conflict of interest in the inspection.

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Prescriptive vs. Performance: Choosing the Right Compliance Pathway

California gives you two ways to demonstrate Title 24 compliance. Understanding the difference can save you thousands of dollars on a remodeling project.

The Prescriptive Path

This is the checklist approach. The code specifies exact requirements for each building component: specific R-values for insulation, specific U-factors for windows, specific efficiency ratings for HVAC equipment, specific efficacy levels for lighting. Meet every specification exactly, and you comply.

When prescriptive works best: Simple projects with one or two compliance triggers, where standard materials and equipment easily meet the requirements. A straightforward HVAC replacement or a window-for-window swap with code-compliant products is often simplest to do prescriptively.

The limitation: No flexibility. If one component falls short, you can't make up for it with better performance elsewhere. Every item on the checklist must pass individually.

The Performance Path

This approach uses energy modeling software (CBECC-Res for residential projects) to calculate your entire home's energy use as a system. Instead of checking each component individually, the model evaluates whether the overall energy consumption of the proposed design meets the code's energy budget.

When performance works best: Complex projects where trade-offs save money. For example, if your design calls for large windows that don't meet prescriptive U-factor requirements, a performance model might show that a higher-efficiency HVAC system or additional attic insulation compensates for the window heat loss, and the overall design still meets the energy budget.

The cost: The performance path requires hiring a registered energy consultant to run the modeling software and produce the compliance documentation (the CF-1R form). This typically costs $500 to $2,000 depending on project complexity.

The potential savings: On a project where prescriptive compliance would require expensive specialty windows or equipment upgrades, the performance path can save $3,000 to $10,000 or more by allowing strategic trade-offs.

Which Path Should You Choose?

For most remodeling projects, we evaluate both pathways during the design phase and recommend whichever option results in the lowest total project cost.

Sometimes prescriptive is cheaper. Sometimes performance saves thousands. The right answer depends entirely on your specific project, and it's a conversation we have with every client before plans go to permit.

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What Changed in the 2025 Code (Effective January 1, 2026)

The 2025 Energy Code represents California's most aggressive push toward building decarbonization. The CEC estimates these updates will save $4.8 billion in energy costs over 30 years and reduce greenhouse gas emissions by approximately 4 million metric tons. Here are the changes most relevant to residential remodeling:

Heat pump emphasis. The code establishes energy budgets for residential buildings that assume heat pump performance as the baseline for both space heating and water heating. Gas-fired equipment is still permitted, but meeting the energy budget becomes harder without heat pumps, potentially requiring more expensive compensating measures.

Updated envelope requirements. Ceiling, wall, and window efficiency standards have been tightened. Homeowners replacing windows or modifying the building envelope will face stricter U-factor and insulation R-value requirements than under the 2022 code.

Smart thermostat requirements. New HVAC systems must be compatible with smart thermostats that can access utility pricing signals, allowing the system to automatically shift energy use to lower-cost periods.

Strengthened ventilation standards. Indoor air quality requirements have been updated, which affects projects that modify or add mechanical ventilation.

Wildfire rebuild exception. Executive Order N-29-25 temporarily suspends certain 2025 requirements (specifically solar and battery storage) for projects rebuilding structures damaged by the 2025 LA wildfires. Those projects must still be solar-ready and comply with all other Title 24 requirements.

The Real Cost: Title 24 Compliance by Project Type

Here's what Title 24 compliance actually adds to common Los Angeles remodeling projects in 2026.

Project Type	Typical Title 24 Compliance Cost	What's Included
Kitchen Remodel (HVAC untouched)	$500 – $1,500	Lighting compliance, possible window upgrades
Kitchen Remodel (with HVAC replacement)	$1,500 – $4,000	Energy consultant, duct leakage test, refrigerant verification, lighting
Bathroom Remodel	$300 – $1,000	Lighting compliance, ventilation verification
Window Replacement (whole house)	$1,000 – $3,000	Energy modeling to verify U-factor/SHGC compliance
Room Addition (200–400 sq ft)	$3,000 – $6,000	Full compliance: insulation, windows, HVAC, lighting, QII, energy modeling
ADU (new construction)	$4,000 – $8,000+	Full compliance plus potential solar/battery requirements
Whole Home Remodel	$5,000 – $10,000+	Comprehensive modeling, multiple HERS inspections, full envelope compliance

These costs are separate from and in addition to your construction costs, permit fees, and architectural fees. A proper remodeling estimate should show Title 24 compliance as its own line item so you can evaluate the full picture.

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How We Handle Title 24 at California Construction & Remodeling Experts

We don't treat Title 24 as an afterthought. Here's how compliance is built into every project we manage:

During design, we identify all Title 24 triggers and evaluate both prescriptive and performance compliance pathways. We coordinate with our energy consultant during this phase, not after plans are submitted.

During estimating, we include all Title 24 costs as a separate, transparent line item: energy consultant fees, HERS inspection fees, and any material or equipment upgrades required for compliance. You see these costs before you sign anything.

During construction, we schedule HERS inspections at the correct construction milestones. QII before drywall. Duct testing after HVAC installation. Refrigerant charge after system commissioning. The testing is built into our construction schedule so it never causes delays.

During closeout, we ensure all compliance documentation (CF-1R forms, HERS verification reports, installation certificates) is properly registered in the HERS data registry and available for your building department's final inspection.

This approach means your permit application includes complete Title 24 documentation from the start, which reduces plan check corrections, speeds up approval, and eliminates the budget surprises that plague projects where compliance is treated as a last-minute exercise.

If you're planning a remodel and you want a contractor who understands California's energy code as well as they understand construction, let's talk. The consultation is free, and we'll tell you exactly which Title 24 requirements apply to your project and what they'll cost before you commit to anything.

About the Author

This guide was produced by the expert team at California Construction & Remodeling Experts. Specializing in high-end Los Angeles renovations and structural safety, we bridge the gap between architectural vision and complex California building codes. We are fully licensed ( CSLB #1130438 ), bonded, and dedicated to transparent, code-first remodeling for homeowners in Beverly Hills, West Hollywood, and beyond.

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