California’s Rooftop Solar Mandate: How to Succeed

This year, California’s Title 24 mandate went into effect, requiring all new residential homes to be built with solar PV. This represents a new business opportunity for the industry, which in the coming years will help drive solar expansion and job growth in America’s largest solar market. We asked Aurora Solar, a solar design and sales software company, about the approaches and strategies that will be key to a company’s success.

For homebuilders, solar installers, and other stakeholders, Title 24 is a change to the state’s building code standards, laying out a new set of requirements and considerations that could fundamentally revamp their work processes. The main requirement for homebuilders is to show that the PV system is sized to offset the home’s energy usage. The mandate requires energy efficiency measures to be designed first, so that a PV system is accurately sized to offset the energy consumption of the home. The other key requirement is the ability to document that there is sufficient solar access for the system to generate the right amount of energy. In other words, this means showing that shading from trees or other buildings won’t interfere with the PV system’s production.

To stay in compliance, homebuilders, installers, and energy consultants will need to work more collaboratively, says Meredith McClintock, Head of Business Development at Aurora Solar. McClintock noted that builders have typically worked with energy consultants and solar installers on separate tracks. Now, however, since energy efficiency will impact the sizing and cost of the solar PV system and vice-versa, the process will need to be more iterative to ensure the mandate is met efficiently and effectively. “Increased and earlier collaboration is critical,” says McClintock, “because it will lead to a consensus for what the process will look like, with faster and smoother back-and-forth among stakeholders, and efficient cost tradeoffs between solar and additional measures.”

Title 24 is expected to result in solar installations on an additional 65,000 homes every year.54 To capitalize on that growth, there are several key actions industry stakeholders will need to take. Most importantly, according to McClintock, they must learn the new requirements and be familiar with the residential compliance manuals and software guides. “Stakeholders also need to make sure their design and shading analysis tools have all the capabilities necessary to comply and can do so accurately. Otherwise,” she said, “they are at risk of cost overruns from rework.” For example, if a PV system is sized incorrectly or the shade report is inaccurate, they will have to go back and resolve the issue, which could require a lot more time and money.

Aurora Solar has been working with the California Energy Commission (CEC) to find ways to make compliance easier for everyone, and they’ve gotten their software formally approved as a solar assessment tool for compliance. The company will be releasing a Guide to Title 24, which is a comprehensive handbook for stakeholders to understand all the new solar requirements and how Aurora can be used in their workflow to guarantee full compliance. Aurora Solar’s software has the capability to design PV systems from a blueprint, conduct shade analysis, forecast how much energy a PV system will produce, and provide other tools now critical to Title 24 compliance. “From our in-depth conversations with the CEC,” said Sunny Wang, Director of Government Affairs & Communications at Aurora Solar, “it was great to learn that our software already has the functionalities needed to help home builders and installers meet the requirements.”

Useful Resources for Title 24 Compliance