Every time a heating or cooling system is installed or replaced in California, it has to be checked against a set of state rules that most homeowners have never heard of. Those rules are the California Energy Code, also known as Title 24. The code is not trying to make your life difficult. It exists because the state has set targets for energy use, and the heating and cooling system is usually the biggest energy user in a house.
Here is what it actually changes for you when you replace a system.
What is Title 24 in plain terms?
Title 24 Part 6 is the part of the California Building Standards Code that deals with energy efficiency. It sets minimum performance standards for new and replacement equipment in homes and commercial buildings, and it covers lighting, insulation, ventilation and heating and cooling in one document.
The code is updated on a three-year cycle. The 2022 code took effect on 1 January 2023, the 2025 code cycle took effect on 1 January 2026, and the next update is the 2028 cycle. The important thing for a homeowner is that the version in force when your permit is pulled is the version your system has to meet.
There are two parts to compliance that people mix up. The equipment has to be efficient enough, and the installation has to be done to the standard. A highly efficient unit installed on badly sealed ducts is a legal installation that wastes energy, so the code covers both halves.
The five changes that affect an HVAC upgrade
1. Higher efficiency minimums for the equipment
The code raised the minimum cooling and heating efficiency ratings. SEER2 replaced the older SEER rating and HSPF2 replaced HSPF, because both newer ratings measure performance across a wider range of conditions. A system that would have been acceptable a few years ago may not be a legal install today.
2. Heat pumps are the default recommendation
California is moving buildings away from gas combustion and towards electric equipment, and the code reflects that. For most replacements, a heat pump is now the recommended option, and in many cases it is the only sensible one. A heat pump heats and cools with the same equipment, which is why it has become the default in a state with mild winters and hot summers.
3. Duct sealing and leakage testing
New ductwork has to be sealed at the joints, and the system has to be tested for leakage. This is the part of the code that most directly affects your comfort, because a system that leaks air is a system that works harder for the same result. It also protects the equipment, since a starved blower and a low refrigerant charge both shorten the life of the parts.
4. Smart thermostat compatibility
New systems are expected to work with a programmable or smart thermostat, and the thermostat is normally part of the permitted scope. In practice this means a thermostat that can run schedules, and for many homeowners a smart one that you can control from a phone.
5. Mechanical ventilation and indoor air quality
The code addresses how fresh air gets into a well-insulated, airtight house. A house that is sealed tight is efficient, but it needs a deliberate path for outdoor air, and the code is where that requirement comes from. This is also where an energy recovery ventilator becomes relevant in a home that has been tightened up over the years.
| Code requirement | What it means in practice |
|---|---|
| Higher efficiency minimums | SEER2 for cooling and HSPF2 for heating, set at a higher floor than the ratings they replaced |
| Heat pump as the default | Most replacements are quoted as a heat pump rather than a gas furnace and a separate air conditioner |
| Duct sealing and leakage testing | New or altered ductwork is sealed at the joints and tested, and the result goes on the paperwork |
| Smart thermostat compatibility | The new system is expected to work with a programmable or smart thermostat |
| Mechanical ventilation and air quality | A tight house needs a deliberate path for outdoor air, which is where an ERV comes in |
None of these requirements are optional extras you can decline. They are part of the permit, which means the equipment and the installation both have to line up with the code that is in force on the day the permit is pulled.
What a compliant installation looks like on paper
When your job is done properly, you should be handed paperwork you can actually read. Here is the list to ask for.
- The permit for the work, and the final inspection record
- The model numbers and the efficiency ratings of both the outdoor and indoor units
- Confirmation that the outdoor and indoor units are matched as a set
- The duct sealing and leakage test result for any new or altered ductwork
- The manufacturer warranty paperwork and the labour warranty from the installer
- The rebate paperwork, if you are claiming anything from a state programme
You should also get a copy of the equipment and the work in a written quote before anything starts. A quote that arrives after the work is not a quote.
What to ask for in your quote
- Ask which efficiency ratings the quoted equipment carries, and confirm they meet the current code minimum
- Ask whether the ductwork is being sealed and tested, and whether the test result is on the paperwork
- Ask whether a permit is included, and who pulls it
- Ask whether the thermostat is included and whether it is programmable or smart
- Ask what the labour warranty is, in years, on top of the manufacturer parts coverage
- Ask what happens to the price if the ductwork turns out to need more than the quote allows for
On a central replacement our standard cover is 10 years of manufacturer parts coverage plus 1 to 5 years of labour from us, with a 5-year warranty on the installation. Financing is available on qualifying credit, there is a military discount on a new system installation, and we help you with California TECH Clean California rebate paperwork. We are a licensed contractor, not a utility, and we will tell you plainly what you qualify for.
When to stop and call a licensed technician
- Stop if the quote does not mention a permit. If the job is permitted, the code is checked, and if it is not, you are the one carrying the risk
- Stop if nobody has run a load calculation. Code compliant equipment that is the wrong size will still fail to keep up in July
- Stop if you are being told the existing ducts are fine without any testing. Sealing and testing are the part of the code that saves you money every month
- Stop if you want to reuse old ductwork that has been patched over the years and has never been inspected
Call (209) 351-6000 and tell us what you are planning. We will size the system with a Manual J load calculation, tell you what the current code requires for the job, and put the price in writing before anything is ordered.
