Title 24 HVAC Requirements in 2026: What Contractors Need to Know

Title 24 is one of those things that every HVAC contractor in California deals with on every single job, yet somehow it still trips people up constantly. The 2025 code cycle brought changes that are now fully enforced, and I've seen experienced contractors, people with fifteen years in the trade, get permits kicked back because they missed something that changed between cycles. The energy code is not optional. It is not something you can fudge. And building departments have gotten significantly better at catching noncompliance, partly because the software they use to review applications has improved and partly because the state has been pressuring local jurisdictions to tighten enforcement.

So this is a practical walkthrough. Not a summary of the entire energy code, but the specific pieces that matter when you're pulling an HVAC permit and trying to get it approved on the first submission.

The CF-1R Form Is Your Starting Point

Every residential HVAC project that requires a permit also requires a CF-1R compliance form. This is the Certificate of Compliance that documents the energy performance of the proposed installation. It gets generated through approved compliance software like EnergyPro or CBECC-Res, and it needs to demonstrate that your project meets or exceeds the prescriptive or performance requirements for the applicable climate zone.

The prescriptive path is straightforward: your equipment and installation must meet minimum efficiency standards, duct leakage limits, and insulation requirements spelled out for your specific climate zone. The performance path gives you more flexibility by letting you trade off between different measures, but it requires modeling the whole building's energy performance, which is more work than most straightforward changeout jobs warrant. For a standard equipment replacement, you're almost always going prescriptive.

One thing that catches contractors off guard: the CF-1R must be completed and available before the permit application. Not after. Not "we'll get it to you before inspection." Several Bay Area jurisdictions now require it as an upload at the time of application, and they will reject your submission outright if it's missing or if the data doesn't match the scope described in your permit application.

Equipment Efficiency Minimums: They Went Up

The 2025 cycle raised minimum efficiency requirements across the board, and these are now the enforced standard in 2026. For split system air conditioners and heat pumps under 65,000 BTU, you're looking at a minimum SEER2 of 15.0 in most climate zones. Heat pumps have an additional HSPF2 requirement of 7.8. Gas furnaces must meet a 92% AFUE minimum in climate zones 1 through 9, and 80% AFUE is still acceptable in zones 10 through 16, though many contractors are installing higher efficiency units anyway because utility rebate programs have made them cost-competitive.

The shift from SEER to SEER2 and from HSPF to HSPF2 still generates confusion. These are not the same numbers. SEER2 ratings are tested under a different, more realistic protocol that results in lower numbers than the old SEER rating for equivalent equipment. A unit that was rated 16 SEER under the old system might test at 15.2 SEER2. So when you're specifying equipment on your permit application, make sure you're using the SEER2 rating from the AHRI directory, not the old SEER number from a manufacturer's brochure. I've seen this exact mistake cause rejections at least a dozen times in the last year.

Climate Zones: Why They Matter More Than You Think

California has 16 climate zones, and they are not arbitrary lines on a map. The prescriptive requirements change zone by zone because a system that makes sense in foggy San Francisco (Zone 3) would be wildly undersized for the summer peak loads in the Central Valley (Zone 12). What this means practically is that the same equipment swap, identical brand, model, and installation, might pass Title 24 in one city and fail in another city twenty miles away if they fall in different climate zones.

The Bay Area alone spans zones 2, 3, 4, and parts of 12. San Francisco is Zone 3. San Jose is mostly Zone 4. Parts of the East Bay that get hot in summer are Zone 12. If you work across multiple cities, you cannot assume the same compliance strategy works everywhere. The CF-1R must specify the correct climate zone for the project address, and it will calculate requirements accordingly. Get the zone wrong and the entire form is invalid, which means your permit is going to get rejected. We've talked to shops who discovered this the hard way when they had a template CF-1R they were reusing across jobs and forgot to update the climate zone field.

Duct Testing and Sealing Requirements

Duct leakage testing under Title 24 applies when you're installing new ducts, replacing more than 40 feet of existing ducts, or when the system is being altered in a way that affects duct performance. The leakage limit for new ducts is 5% of nominal system airflow when tested at 25 Pascals. For existing duct systems being connected to new equipment, the limit is 15% or the documented existing leakage rate, whichever is less.

This matters because duct testing requires a HERS rater, which adds both cost and scheduling complexity to the job. If you're just doing a straight equipment replacement and not touching the ducts, you can often avoid the duct test requirement. But "not touching the ducts" means not touching the ducts. If you disconnect and reconnect the plenum, some jurisdictions interpret that as an alteration that triggers testing. The safe play is to know your local building department's interpretation before you start work, because finding out at inspection that they expected a duct test you didn't schedule is a guaranteed delay. Check our HVAC permit guide for jurisdiction-specific details on when duct testing is triggered.

HERS Verification: What Gets Tested

HERS (Home Energy Rating System) verification is required for certain measures to confirm that the installation matches what was promised on the CF-1R. For HVAC work, the most common HERS-verified measures are refrigerant charge verification, airflow verification, and duct leakage testing. The rater performs the test, enters the results into the HERS registry, and the building department can then verify compliance electronically.

Refrigerant charge verification requires the system to be tested using either the superheat or subcooling method, depending on the metering device. Airflow must be verified at 350 CFM per ton minimum, though higher is better and some equipment requires more. These tests happen after installation, which means you need to coordinate HERS rater scheduling with your install timeline. In the Bay Area, HERS raters can be booked out a week or more during busy season. Plan accordingly.

The Most Common Title 24 Mistakes That Get Permits Rejected

After processing thousands of California HVAC permits, the same errors come up over and over. Wrong climate zone on the CF-1R is probably the single most frequent one. Using SEER instead of SEER2 ratings is a close second. Mismatched equipment model numbers between the permit application and the compliance documents is another classic, usually because the contractor changed equipment after generating the CF-1R and forgot to update it.

Missing the HERS verification requirement is a big one too. Some contractors don't realize their project triggers HERS testing until the final inspection, which means they have to schedule a rater, wait, get tested, and then reschedule the inspection. That can add a week to the close-out timeline. Incomplete documentation is the catch-all category: missing load calculations, missing equipment specifications, incomplete scope descriptions on the application. Building departments are not going to guess what you meant. If the application is ambiguous, it gets sent back.

For more on how long the HVAC permit process takes in California, including how rejections affect your timeline, we break down the full process and typical wait times by jurisdiction.

What Changed From the Previous Cycle

The biggest shift in the 2025 cycle, now enforced through 2026 and beyond, was the increased push toward electrification and heat pump adoption. The code didn't outright ban gas equipment in most applications, but it made the compliance path significantly easier for heat pumps. If you're installing a heat pump, you get more favorable prescriptive requirements. If you're installing a gas furnace with an AC condenser, the efficiency minimums are tighter and the compliance pathway involves more documentation.

The ventilation requirements also tightened. Mechanical ventilation per ASHRAE 62.2 is required in more situations than before, particularly when you're tightening the building envelope as part of the HVAC scope. And the documentation requirements around indoor air quality got more explicit. You can't just check a box anymore. You need to show that the ventilation system meets the calculated requirements for the specific dwelling.

None of this is impossible to navigate. But it requires attention to detail, current knowledge of the code, and an understanding of your specific climate zone's requirements. Most contractors know the trade. The paperwork is the bottleneck. And that's a solvable problem.