Yes, California’s solar mandate means most new residential construction—and even some commercial buildings—must include solar. Title 24 of the California Energy Code locked this in back on January 1, 2020. Think about it: every new home, every low-rise multi-family unit (up to three stories) has to come with a solar photovoltaic (PV) system. California’s not messing around when it comes to clean energy goals.
This isn’t some pie-in-the-sky initiative, either. It’s all about cutting down on pollution, ramping up renewable energy use, and saying a big fat “no” to fossil fuels. This law covers single-family homes, townhouses, and charming multi-family buildings that stay under the three-story threshold. And it doesn’t stop there—as of 2023, even some commercial structures joined the solar party.
So, why all the fuss about solar? It’s a key part of California’s roadmap to clean energy domination. By 2030, the state’s plan is for half its electricity to come from renewable sources, with a full clean sweep by 2045. Solar on new builds isn’t just a rule; it’s a statement.
What Is California’s Solar Mandate for New Construction?
California’s Solar Mandate lives in Title 24—the state’s Building Standards Code, Part 6, to be exact. This isn’t a suggestion; it’s a requirement, written into law and overseen by the California Energy Commission (CEC).
What does it say?
Starting January 1, 2020, if you’re building a single-family home, a townhouse, or a low-rise multifamily building (three stories or less), solar panels are mandatory.
No exceptions, no wiggle room.
The idea here is straightforward: every new home in California should generate enough solar energy to cover its annual electricity needs. But one size doesn’t fit all. The system’s size depends on a few variables—how big the house is, where it’s located, and how much energy it’s expected to use.
If you want to go the extra mile, batteries can help. They’re optional, for now, but they let you shrink the required system size by up to 25%. That’s a decent chunk.
So how did the solar mandate become law? In 2018, the CEC voted to adopt the mandate after plenty of public hearings and input from industry experts. From there, it made its way into the state’s Building Standards Code. Now, it’s tied directly to the building permit process. No solar, no permit, no construction.
Why all the fuss? California has big climate goals—like 100% clean energy by 2045, thanks to Senate Bill 100. Making solar panels a standard feature of new construction is one way to chip away at greenhouse gas emissions and push the state further into renewable energy territory.
What makes this so significant is the shift it represents. Solar isn’t a luxury add-on anymore; it’s a baseline requirement. Every new roof in California contributes to a larger clean energy system. It’s a step forward.
How Much Do Solar Panels Add to the Cost of New Construction?
The California Energy Commission (CEC) puts the average cost bump for a single-family home at around $9,500 when adding solar—though, like most things, the final number depends on the specifics. Here’s what goes into it:
System Costs
Currently, solar panels in California average $3.14 per watt (as of January 2025). That means a standard 5 kW system costs:
- Total system price: $15,700
- After the 30% federal tax credit: $11,000
Pretty steep at first glance, right? But dig into the numbers—things start to look better.
System Size Variations
The CEC also notes that new homes usually get systems ranging between 2.7 kW and 5.7 kW. Why? Because location and house size make a difference. A bigger home or one in a low-sun area? Likely needs a bigger system—and higher costs.
Permits and Inspections
A lot of folks forget to factor in these extras:
- Permit fees: $450 max for a 5 kW setup (add $15 per kW above 15 kW)
- Inspections: $500–$1,000 for permits and inspections combined
Altogether, they’re about 3–5% of the total system cost. Not pocket change, but not the biggest slice of the pie either.
Construction Extras
Building a solar-ready house isn’t just about slapping panels on the roof. Builders may need to:
- Adjust roof layouts
- Upgrade electrical systems
- Integrate solar into construction blueprints
Which Types of New Construction Require Solar Panels in California?
Builders of single-family homes, townhouses, and three-story-or-less multi-family buildings, for starters. Here’s a quick rundown of the construction categories and how they fit into California’s solar requirements:
- Single-Family Homes: Individual residential units, including detached homes.
- Townhouses: Multi-story residential units that share walls but have separate entrances.
- Low-Rise Multi-Family Buildings: Residential structures with up to three stories, such as duplexes or small apartment complexes.
- High-Rise Residential Buildings: Structures taller than three stories, including larger apartment complexes.
- Non-Residential Buildings: Commercial properties like offices, retail spaces, schools, warehouses, hotels, motels, restaurants, and theaters.
- Exempt Buildings: Certain structures that do not meet the criteria for residential or commercial solar requirements as defined under the California Building Code.
Before 2023, the mandate’s definition was fairly straightforward: it covered residential properties under the “low-rise residential” category. As defined by California’s Building Standards, low-rise residentials are structures with one to three stories, primarily for residential use—think family homes, duplexes, and small apartment complexes.
In 2023, however, the state drew a bigger circle around what qualifies. The expanded scope officially added commercial properties, marking a significant shift in legal definitions and energy expectations. Offices, retail shops, schools, warehouses, hotels, motels, restaurants, and even theaters were roped into compliance starting January 1, 2023.
These additions fall under “non-residential” and “high-rise residential” categories within Title 24’s framework. Legally speaking, high-rise residential buildings—structures taller than three stories—were reclassified alongside commercial buildings for solar compliance.
What does that mean for builders? High-rises need shared solar systems or commercial-grade installations, not the smaller setups you’d find on single-family homes.
Warehouses and offices, on the other hand, must install systems tailored to their energy profiles—determined by size, usage, and occupancy types. The mandate’s precise language ensures no ambiguity: any new structure that qualifies as “commercial” or “high-rise residential” under the California Building Code now falls within its solar-powered grasp.
And if you’re scratching your head wondering about apartment complexes or commercial properties, yes—they’re included. It’s not a free-for-all, though; some buildings are exempt.
What Are the Exemptions to the Solar Panel Requirement?
California’s Solar Mandate is ambitious, but there are exceptions—because forcing solar onto a rooftop that can’t support it just doesn’t make sense. Here’s a quick breakdown of the exemptions:
- Shading Issues: Roofs with significant shading from trees, buildings, or other permanent obstructions that limit solar energy production to less than 70% efficiency compared to an unshaded system.
- Small Roofs: Buildings with roof space too small to accommodate a solar system larger than 1.8 kW.
- Remote Locations: Properties located off-grid, without reasonable access to the electrical utility grid.
- Cost Concerns: Situations where the cost of solar installation exceeds its lifetime energy savings, based on a cost-effectiveness analysis.
- Community Solar: A compliance option where builders participate in shared solar programs instead of installing individual systems.
- Special Buildings: Seasonal or temporary structures, or buildings intended for low or limited occupancy, like hunting cabins or event spaces.
- High Snow Load Areas: Locations with extreme snow loads that exceed the capacity of available photovoltaic (PV) panels.
- Disaster Rebuilds: Homes being rebuilt after natural disasters, such as fires or earthquakes, where exemptions help expedite recovery efforts.
Shading Issues
Let’s start with shading. If your roof is covered by shade—whether it’s from trees, nearby buildings, or even that hill blocking the sunlight—the state doesn’t expect you to install panels that won’t pull their weight. But it’s not a free pass. You’ll need a solar assessment to prove that your roof can’t generate at least 70% of the energy that an unshaded solar system would. For example, the local building department in Placer County requires you to submit documentation, including a site plan that shows shading proximity to remaining trees and where the solar assessment readings were taken. Combine that with a CF1R form (the state’s compliance document), and you’ve got your exemption application started.
Small Roofs
Not every roof is built to be a solar powerhouse. If the system size required by the mandate doesn’t fit (like less than 1.8 kW), your building might qualify for a partial or total exemption. For instance, this could apply to micro-homes or accessory dwelling units (ADUs) with minimal roof space. Local building departments will review your roof dimensions and proposed system design to determine if the exemption applies.
Remote Locations
Live off-grid? The mandate isn’t going to chase you down in the middle of nowhere. Homes without access to the electrical grid can often qualify for exemptions. Take rural areas in places like the Sierra Nevada foothills, where properties may not even have access to basic utility services—these homes often receive exemptions outright.
Cost Concerns
This one’s about money. If the cost of installing a solar system outweighs the savings it’ll generate, you might not have to install it. But don’t expect a quick handshake and a nod—you’ll need a cost-effectiveness analysis to back this up. For example, projects where the installation costs far exceed the energy savings over a 30-year period might fall into this category. Builders in areas with higher-than-average installation costs often use this exemption to justify alternative measures.
Community Solar
Here’s another option: skip the panels entirely and participate in a community solar program. Instead of individual systems, builders can buy into shared solar projects like SMUD’s Neighborhood SolarShares program, approved by the CEC in 2020. This allows builders in Sacramento and nearby areas to meet the solar requirement without rooftop installations—ideal for developments where rooftop solar isn’t feasible due to design or space constraints.
Special Buildings
Not all buildings fit the mold. Seasonal homes, temporary structures, or buildings designed for limited occupancy are often exempt. For example, a hunting cabin in a remote area that’s only used a few weeks a year wouldn’t be subject to the same requirements as a primary residence. Similarly, temporary structures for construction or events also fall into this category.
High Snow Load Areas
If you’re building in a region with heavy snow loads—where the panels available can’t handle the weight—you might qualify for an exemption. Placer County, for instance, has guidelines specifying that projects with design snow loads exceeding the capacity of rated panels are eligible for exceptions.
Disaster Rebuilds
Rebuilding after a disaster? Whether it’s a wildfire, earthquake, or something else, the rules are more flexible. Following the devastating Camp Fire in 2018, the town of Paradise allowed exemptions for solar installations on rebuilds, prioritizing recovery efforts over immediate compliance with the mandate.
So how do you find out if you qualify for a solar exemption?
Exemptions aren’t automatic. You’ll need to submit requests—usually during the building permit application—and provide supporting documents. Most decisions take a couple of weeks, but some can stretch out depending on complexity or workload at your local building office.
Even if you qualify for an exemption, your building might still need to be “solar-ready.” That means having the infrastructure in place to add solar panels later. California wants to keep options open for the future.
How do we comply with the solar requirement for new construction?
Meeting California’s Solar Mandate might not be rocket science, but it’s definitely a process. Below is the six-step checklist for new constructions in California. Cutting corners isn’t an option, so buckle up:
- Design the System: Calculate energy needs to determine the right system size.
- Use Energy Modeling Tools: Approved software ensures your plans meet Title 24’s standards.
- Secure Permits: Submit detailed plans for approval by local authorities.
- Install Smartly: Hire licensed professionals for everything—panels, wiring, inspections.
- Inspect and Certify: Pass local and utility inspections to get Permission to Operate (PTO).
- Document Everything: Give homeowners the manuals, warranties, and guides they’ll need.
Design the System
Start with the math. To size your solar setup, calculate projected energy use with a formula approved by the California Energy Commission (CEC):
Where:
- kWdc = required system size (kilowatts direct current)
- CFA = Conditioned Floor Area
- NDU = Number of Dwelling Units
- A and B = adjustment factors based on climate zone
Bring in certified professionals—think NABCEP-certified solar designers or CABEC-certified energy consultants—to create system layouts. They’ll account for roof orientation, shading, and integration with existing electrical systems.
You’ll also need to document everything in a CF1R-PRF-01-E form. Here are the energy compliance requirements in the CF1R-PRF-01-E form:
- Total Energy Design Rating (EDR): The Total EDR evaluates a building’s overall energy performance by combining two key components: the Energy Efficiency EDR and the Solar Electric EDR. A lower Total EDR score reflects superior energy performance.
- Energy Efficiency EDR: This metric measures a building’s energy efficiency by assessing systems like heating, cooling, ventilation, and water heating, while excluding the effects of solar energy generation.
- Solar Electric EDR (PV/Flexibility EDR): This component focuses on the impact of solar photovoltaic systems, battery storage, and other demand-response measures on a building’s energy performance.
- Proposed Design Total Energy Use: This refers to the predicted energy consumption of a building based on its design, including all energy sources and end uses, as modeled using energy analysis software.
- Standard Design Total Energy Use: This metric represents the energy consumption of a baseline building that complies with the minimum energy code requirements. It serves as a benchmark for comparing the proposed design’s performance.
Use Energy Modeling Tools
Don’t just guess—run the numbers through approved software like CBECC-Res, EnergyPro, or REM/Rate. Input your building’s specs, run simulations, and check your system against Title 24 standards. These tools generate compliance reports, including CF1R forms, that must go to your local building department.
Secure Permits
This step’s all about paperwork. Submit site plans, electrical diagrams, structural calculations, and compliance forms to your local building department. Permits usually cost $200–$500 for residential projects. Most plan reviews take 2–4 weeks, so plan ahead.
You’ll also need fire safety approval in some areas, particularly if your project involves battery storage or unique rooftop configurations. Don’t forget to include a Solar PV Standard Plan, which follows the California Solar Permitting Guidebook.
Install Smartly
Installation isn’t a DIY project. It has to be done by licensed contractors—solar installers must hold a C-46 Solar Contractor license from the Contractors State License Board (CSLB). Electricians need state certification, too.
Here’s what the process looks like:
- Install racking and mounting systems on the roof.
- Secure solar panels and connect them to inverters.
- Integrate the system with the home’s main electrical panel.
- Test everything to ensure it meets safety and performance standards.
Keep in mind, CAL FIRE has specific safety requirements for rooftop solar systems, and all work must comply with the National Electrical Code (NEC) Article 690.
Inspect and Certify
No shortcuts here. You’ll need to schedule inspections with local building officials and your utility company. Inspections include:
- Electrical Check: Ensures the system meets code requirements.
- Fire Safety Review: Confirms compliance with CAL FIRE guidelines.
- Utility Approval: The utility company issues a Permission to Operate (PTO) after confirming the system can safely connect to the grid.
Be prepared to submit additional forms like the CF2R-PVB-01-E (Certificate of Installation) and CF3R-PVB-01-E (Certificate of Verification).
Document Everything
Before handing over the keys, builders must provide homeowners with:
- A user manual for the system.
- Warranty details (e.g., 25 years for panels, 10 years for inverters).
- A maintenance schedule and troubleshooting guide.
- Emergency shutdown procedures.
Make sure the system is registered with the manufacturer for warranty purposes and that homeowners know who to contact for maintenance.
Additional Compliance Options
If rooftop solar isn’t feasible, consider alternatives:
- Community Solar: Participate in programs like SMUD’s SolarShares, where energy is generated off-site but credited to the homeowner’s account.
- Battery Storage: While not mandatory, batteries can reduce the required solar system size by up to 25%. They also qualify for extra incentives, like the Self-Generation Incentive Program (SGIP).
- Exemptions: For buildings with shading issues or other challenges, submit detailed exemption requests, including shading analysis and solar access reports.
Following these steps ensures compliance with the mandate and maximizes the benefits of solar energy for homeowners. Skipping steps? Not an option. Get it done right the first time.
What Are the Benefits of Requiring Solar Panels for New Construction?
Let’s talk benefits—why California’s Solar Mandate isn’t just another rule in the books. Here are the eight main benefits of mandating solar panels on new constructions:
- Lower Electricity Bills: Homeowners can save between $500 and $1,500 every year on electricity. Over 25 years, that’s $19,000 to $25,000. Real savings, not hypothetical numbers.
- Environmental Impact: The mandate offsets emissions equivalent to taking 115,000 gas-powered cars off the road every year. It’s also projected to cut around 4 million tons of CO₂ annually.
- Increased Home Value: Homes with solar systems see resale values jump by an average of 3.7%—about $17,000 for the median-priced California home.
- Energy Independence: Solar paired with batteries gives homeowners backup power during outages and peak demand periods, making them less dependent on utility companies.
- Job Creation: California’s solar industry employs over 115,000 workers—installers, engineers, manufacturers—you name it. That’s two-thirds of the state’s renewable energy workforce.
- Grid Support: Solar homes reduce strain on the grid, especially during high-demand periods, while improving reliability and cutting transmission losses.
- Innovation Boost: More solar systems mean more demand for better tech, which leads to advancements in efficiency and lower costs over time.
- Long-Term Financial Payoff: Yes, solar systems cost $8,400 to $15,000 upfront, but with federal tax credits and state rebates, most homeowners break even quickly—and then see decades of savings.
Lower Electricity Bills
It’s simple math. Solar systems generate electricity during the day, reducing what homeowners need to buy from the grid. And with net metering, they can sell any excess power back, cutting their bills even more.
Energy storage systems—like the Tesla Powerwall—store surplus energy for nighttime use or peak hours, maximizing savings.
According to the California Energy Commission (CEC), the average household saves $500 to $1,500 annually. Multiply that by 25 years, and you’ve got tens of thousands of dollars staying in your pocket.
Environmental Impact
Solar panels don’t just save money; they help save the planet. California’s Air Resources Board (CARB) reports that the mandate offsets greenhouse gas emissions equivalent to removing 115,000 gas-powered cars annually. That’s around 4 million fewer tons of CO₂ hitting the atmosphere every year. By reducing reliance on fossil fuels like natural gas and coal, solar energy directly supports California’s goal of achieving 100% clean energy by 2045 under Senate Bill 100.
Increased Home Value
Homes with solar systems aren’t just eco-friendly; they’re more valuable. Research shows a 3.7% average increase in resale value, or about $17,000 for a median-priced home in California. And here’s the kicker: that’s often double the initial installation cost. Real estate agents love to market solar systems as energy-saving upgrades, and buyers see the long-term financial benefits—lower bills without needing to invest upfront.
Energy Independence
Solar puts homeowners in control. During grid outages or high-demand periods, systems paired with batteries provide backup power, ensuring essential devices stay on. Companies like Tesla and Enphase Energy are driving battery storage innovation, giving Californians the tools to rely less on utility companies. Think about it—your house powering itself, even during a blackout.
Job Creation
California’s solar industry is a job machine. Over 115,000 people work in roles tied to solar, from manufacturing to installation and maintenance. Utility-scale projects alone created over 10,000 construction jobs in just five years. Companies like Sunrun and Tesla are major employers, while state-supported training programs prepare workers for clean energy careers.
Grid Support
Solar homes reduce grid strain by feeding excess power back during the day. This distributed generation stabilizes the grid, lowers peak demand, and cuts transmission losses. California Independent System Operator (CAISO), which manages the state’s electric grid, relies on solar’s role in balancing supply and demand during high-usage periods.
Innovation Boost
The mandate is driving rapid advancements in solar technology. Institutions like the National Renewable Energy Laboratory (NREL) are leading research to improve efficiency and lower costs. A larger market for solar means economies of scale, which makes cutting-edge tech more accessible to everyone.
Long-Term Financial Payoff
Upfront costs can range from $8,400 to $15,000, but federal tax credits under the Investment Tax Credit (ITC) cut costs by 30%, and state rebates add even more savings. Here’s how it breaks down: the average mortgage increases by about $40 per month when solar costs are factored in, but monthly utility savings average $80. That’s $40 in your favor—every month. Over 25 years, cumulative savings often top $25,000.
The Solar Mandate isn’t just a requirement; it’s an investment—in your wallet, your home, and the planet.
What Is the Future of Solar Requirements for New Construction in California?
California’s solar game? Only getting bigger. The state’s got its sights set on a cleaner, greener future, and solar is right at the heart of it all. Let’s dive into what’s coming next, because if you think the current rules are the finish line—spoiler alert—they’re not even close.
The California Energy Commission (CEC) isn’t sitting still. Not even close.
In 2023, they leveled up, extending solar mandates to high-rise residential buildings and nonresidential ones—offices, retail shops, schools, restaurants. You name it. But they’re not stopping there. Next up? Likely targets include big renovations and retrofits of existing buildings. Think: not just the shiny new stuff anymore.
Pushing Efficiency
January 1, 2026. Mark it down. That’s when the 2025 Energy Code update (if approved) rolls out, bringing the heat—literally. Heat pump technology for water and space heating? They’re doubling down. Multifamily buildings? They’re tightening ventilation standards to boost air quality. Solar and battery storage rules? Getting a refresh.
It’s all about making buildings work smarter, not harder.
Batteries: The New Best Friend
Solar without storage? It’s like coffee without caffeine—good, but not enough.
Back in 2022, they started pushing solar + storage for some commercial buildings. Now? It’s only a matter of time before batteries move from “nice to have” to “you’d better have it” for a lot more types of construction—residential, included.
EV Chargers: The Next Frontier
California’s putting its foot on the accelerator for EV infrastructure, too.
By mid-2024, 15% of parking spaces in new commercial builds must be prepped for future EV chargers, and 5% of those spaces need working chargers right out of the gate. And by 2026? Every new residential unit must include EV charging capabilities. They’re building for a world where electric cars are just cars.
What’s Next?
Crystal balls aren’t a thing, but trends? They’re loud and clear:
- Mandates for solar during major renovations—roof replacements could be prime targets.
- Solar canopies over parking lots. Why waste all that sunlight on asphalt?
- Community solar projects as an easier alternative for properties where rooftop systems don’t make sense.
- Smarter grids, demand response tech—integrating solar into a system that doesn’t just handle energy but actually manages it.
California’s not messing around. These rules? They’re blueprints for how clean energy will take shape—not just here but across the map.
FAQs About California’s Solar Mandate for New Construction
Is solar required for remodels or renovations?
No, the current mandate applies only to new construction. However, large-scale renovations might trigger requirements for making the building “solar-ready.”
What happens if builders don’t comply with the mandate?
Non-compliance can lead to penalties, delays in permits, or issues with occupancy certificates. It’s not worth the hassle.
Can community solar programs count toward compliance?
Yes, builders can opt for community solar as an alternative, especially in cases where on-site installation is impractical.
How is the required solar system size determined?
The system size depends on several factors: building size, climate zone, and projected annual energy usage. It’s calculated to meet energy needs efficiently.
Are there financial incentives to help offset solar costs?
Absolutely. Federal tax credits, state-level incentives, and programs like the SGIP make solar more affordable.
Can homeowners opt out of having solar panels installed?
Not usually. The mandate binds builders to include solar unless specific exemptions apply.
What about apartment buildings or condos? Low-rise multi-family buildings follow residential rules, while high-rise ones adhere to commercial building requirements. Shared systems are also an option.
Does the solar mandate raise home prices? It can slightly bump up the initial cost, but the long-term energy savings and added home value often outweigh the increase.
Are Battery Storage Systems Required Under the Solar Mandate?
Nope, batteries aren’t required, but they’re encouraged. Why? They bring resilience—storing power for when the grid goes down or during peak utility rates. California even sweetens the deal with rebates through its Self-Generation Incentive Program (SGIP).
