Starting January 1, 2026, California's Title 24 code update effectively mandates renewable pool heating by prohibiting gas-only heaters as the primary heat source for new construction.
Starting January 1, 2026, California banned gas pool heaters as the primary heating source for new pools and spas. After decades of gas being the default, the state drew a hard line: solar thermal or heat pump, or you don't get your permit.
If you're building pools in California, this isn't a "watch and wait" situation. It's already the rule. Every new pool permitted this year falls under the updated code. And the contractors who figure this out first are the ones winning the work.
Here's everything you need to know: what changed, how it works, and what to do about it.
The change lives in Section 110.4 of California's Building Energy Efficiency Standards (Title 24, Part 6). Here's what it says, minus the legalese:
New pools and spas must use a solar thermal system or an electric heat pump pool heater (HPPH) as the primary heat source.
Gas-fired heaters and electric resistance heaters are out as primary sources for new installs.
Gas heaters can still be installed, but, only as a backup or supplemental source. They need control logic that keeps them off unless the primary system can't keep up.
That last part is important. You can still put a gas heater next to a solar system for fast heat-ups on cold mornings. But it can't run on its own anymore. The controls have to prove the primary system called for help first.
Title 24 gives you five ways to meet the requirement. The right one depends on the property, the pool, and what matters most to the homeowner.
Install solar thermal collectors sized to at least 60% of the pool's surface area for single-family homes, or 65% for commercial and multifamily.
For a typical 400-square-foot pool, that's 240 square feet of collectors on the roof. The roof needs adequate solar access or specifically what the code calls the Solar Access Roof Area (SARA). Not enough unshaded south- or west-facing roof? This pathway might not work.
Solar thermal has been heating pools in California for over 50 years. It's not new technology. It's proven technology that just became required.
Install a heat pump sized as the primary source, meeting JA16.3 performance standards. Heat pumps need AHRI 1160 certification for their COP (efficiency) ratings.
All heating equipment under this code (heat pumps, gas heaters, solar systems) have to be certified through the CEC's MAEDbS database. For heat pumps specifically, that means meeting UL 1995 (or equivalent) safety standards. Gas heaters need ANSI Z21.56. Solar systems need ICC/APSP 902 and SRCC 400.
Get at least 60% of the pool's annual heating energy from on-site renewables (like rooftop solar PV) or recovered waste heat.
Run both a solar thermal system and a heat pump together, with no other supplemental heaters.
Anything the CEC's Executive Director decides uses no more energy than options 1–4. It's a catch-all for unusual situations, but it requires CEC approval, so it's rarely the fastest route.
The exemptions matter as much as the mandates. Here's what's not affected.
Already have a heater? You're fine. No retrofit required, no upgrade needed. The new rules don't touch you.
Swapping out a broken gas heater for a new one is still allowed. The replacement has to meet current efficiency and emissions standards like no continuously burning pilot lights, low NOx where applicable, but you don't have to add solar or a heat pump. It's a straight replacement.
Remodeling a pool that already has heating? The fuel-switching rule generally doesn't kick in. The mandate applies to new construction and to pools getting heat for the first time.
Not enough roof space with good sun exposure? The solar pathway might be off the table. In those cases, the heat pump or hybrid pathway is usually the move.
Title 24 goes beyond just picking a heater. There are new engineering requirements that affect how the whole plumbing and control system gets laid out.
Hydraulic Optimization (Section 150.0(p))
The code now sets strict hydraulic design standards to cut electrical demand. If your crew has been running standard fittings, this changes things:
Sweep elbows only. No more standard 90-degree elbows. The code requires long-radius sweep fittings to cut friction loss.
Pump sizing by formula. Pumps have to fit a system curve equation: H = C × F². That means real hydraulic calculations, not just matching a pump to a target flow rate.
Straight pipe runs. The code requires specific lengths of straight pipe entering the pump.
These show up at inspection. They're not suggestions.
Any outdoor pool or spa with a gas heater or heat pump now needs a pool cover. That's a new line item for your scope of work, not something to bring up after the homeowner asks why their bill is high.
Pool control systems have to support demand response meaning they can talk to the grid and shift energy use away from peak periods.
Even if you're not installing solar now, new pools need plumbing set up for it later. That means specific pipe stubs, valve placements, and roof penetrations planned into the build from day one.
Upfront cost gets all the attention. But the bid that wins the homeowner's trust is the one that shows total cost of ownership.
Installed cost: $4,500 to $10,000 for a typical residential system
Monthly operating cost: $10 to $25 (increased pump workload and automation electrical consumption only)
Lifespan: 15 to 20+ years
Maintenance: Barely any. No moving parts in the collectors. Occasional valve and controller checks.
Installed cost: $5,500 to $10,000 (equipment + electrical infrastructure)
Monthly operating cost: $50 to $150 (heavily dependent on California utility rates)
Lifespan: 7 to 15 years (the compressor is the weak link)
Maintenance: Refrigerant checks, coil cleaning, compressor service — HVAC license recommended
Installed cost: $3,500 to $6,000
Monthly operating cost (if used as primary): $150 to $400+ depending on gas prices
Lifespan: 5 to 10 years
Maintenance: Heat exchanger inspection, burner cleaning, pilot/ignition service
The math isn't close. Solar costs less to run, lasts twice as long, and barely needs maintenance. Paired with a heat pump or gas heater for backup, it gives homeowners instant heat when they want it and near-zero bills the rest of the time. It's also the system the code was designed around.
Right now, most homeowners don't know these rules changed & most contractors are still catching up. By having an engineering partner that fully understands Title 24 you'll be miles ahead with plans that account for all of the nuance instead of learning from failed inspections.
Contractors who build solar thermal into their standard proposals (not as an upsell, but as the default) will have a real edge. Here's why:
Faster permitting: Solar thermal is the simplest path to compliance. The sizing is straightforward (60% of pool surface area), and permitting departments have been approving these systems for decades.
Easier sell: When the monthly cost is $10 to $25, the "but it costs more upfront" objection goes away fast. Show the homeowner a payback timeline. The savings cover the difference in a few years, and the system lasts 15 to 20+.
Fewer callbacks: No compressor. No refrigerant. No complex electrical components. The most common failure is a panel leak after 15-plus years. Compare that to heat pump compressor failures.
Standing out: The contractor who can explain Title 24 wins the job over the one who says "we'll figure it out." Knowledge is the differentiator right now.
SARA check first: Before you promise solar, confirm the roof has enough unshaded area. Trees, neighboring buildings, bad orientation — any of these can kill the solar pathway. Do this early.
Electrical panel: Proposing a heat pump? Check panel capacity first. A surprise panel upgrade kills bids.
Permit timelines: Title 24 adds documentation — sizing calcs, efficiency ratings, compliance forms. Build extra weeks into your schedule.
Hydraulic design: If your crew is used to standard elbows and catalog pump picks, Section 150.0(p) will need either retraining or outside engineering support.
This is the most aggressive pool heating code change in the country right now. The thing to remember here is that California rarely innovates alone. Electrification mandates, gas phase-outs & building efficiency standards are all being worked on in other states.
Contractors who build their business around this now will be ahead when the next state follows. The ones who wait will be playing catch-up.
Here's the honest version: most pool builders and GCs aren't engineers. And Title 24 compliance, hydraulic optimization, solar sizing calculations, smart control specs is engineering work.
The question isn't whether you need help with this. It's whether you get ahead of it or react to it.
Getting ahead means having an engineering partner who sizes the system right, handles compliance nuances, and hands you stamped plans before your crew breaks ground. Your project moves. Your timeline holds. Your homeowner stays happy.
Reacting means finding out the SARA calc was wrong after panels are on the roof. Or the hydraulic design fails inspection. Or the permit reviewer bounces your submittal because the energy compliance forms aren't right. Now you're weeks behind and your homeowner wants answers.
The SunSmart Engineering team's spent decades designing solar thermal systems, heat pump integrations, and are experts in Title 24-compliant pool heating configurations. We work with pool builders and contractors across California. We handle the engineering, the sizing, the compliance call outs, and the stamped plans that get your project approved the first time.
We're not a pool builder. We don't compete with you. We make your proposals stronger, your permitting faster, and your projects smoother.
If you're building pools in California in 2026 and beyond, the code changed. Your engineering support should match.
Ready to talk through a project or start building Title 24 compliance into how you work? Get in touch below. We'll walk through the details.
We love to hear from new people!
