The new California solar requirements and energy efficiency standards of Title 24, Part 6 took effect on January 1, 2020, and are routinely updated updated every three years. So what do you need to know about Title 24 compliance and calculations to stay on the right side of these new building code requirements?

Read an overview of updates made to Title 24, Part 6 and California’s solar mandate or continue reading for more in-depth details on Title 24 compliance and calculations.

What are the California solar requirements under Title 24?

The updates made to Title 24 by the California Energy Commission (CEC) require all low-rise residential buildings to have solar PV systems that meet the home’s annual electrical usage. At the same time, the CEC wanted to limit how much excess energy is fed back into the grid. To balance these needs, the following equation was developed for Title 24 to calculate the required solar panel system size:

kWpv = (CFA x A)/1000 + (NDwell x B)


  • kWpv = the size of the PV system in kilowatts (DC)
  • CFA = conditioned floor area
  • NDwell = number of dwelling units in the building
  • A and B = adjustment factors based on climate zones where the dwelling will be built

Based on these Title 24 calculations, a 2,000 square foot home in Sacramento (California building climate zone 12) would require a 2.6 kW system while the same home in Fresno (zone 13) would require a 3.3 kW system.

Are there exceptions to the Title 24 solar requirement?

Are there exceptions to the Title 24 solar requirement?

Yes! The updates to Title 24, Part 6 were written to consider the needs of the environment, customers, home builders, and utility companies and to offer as much flexibility as possible. Because of this, there are exceptions and limits to the solar requirement for new California homes.

For starters, no solar panel system is required on homes that are excessively shaded. Builders are also able to opt for additional energy efficiency, demand-responsive technology, thermal storage, and/or battery storage options to reduce the required solar panel system size. The CEC is also looking into community solar options as an alternative to home solar systems.

Design and Consulting for Home Builders

Design and Consulting for Home Builders

Our residential design and consulting team has completed over 36,000 home designs totaling over 115 MW. We offer installation-ready solar PV permit packages for new home construction projects or consulting based on your needs. Our team’s uniquely collaborative approach will ensure that your design and build needs are met, and our quick turnaround time will keep your project on track.

Read more about how our team can help or reach out to get a free consultation today.

What Our Customers Say

When we decided to pursue a solar system installation, we selected Namasté Solar based on the merits of their experience, passion, and dedication to a high level of customer service and quality work, as well as a demonstrated commitment to holistic business practices that benefit all project stakeholders.

— New Belgium Brewing Company

New Belgium Brewing Company

By installing a new roof, a solar PV system, and energy-efficient lighting, we were able to modernize our office – Making it more comfortable for our employees and tenants, lower our energy costs, and reduce our carbon footprint. All with no money down.

— Matt Emerson, President of CEAVCO Audio Visual

Matt Emerson, President of CEAVCO Audio Visual

Namasté Solar pioneered the integration of PV into the Denver Public School system. The project included installations on 16 schools and required a complex logistical strategy due to unique electrical services, structural engineering requirements, and school schedules. DPS found the Namasté Solar team to be highly professional, knowledgeable, extremely collaborative, and eager to work with our team.

— Jim Faes, Denver Public Schools

Jim Faes, Denver Public Schools

This project demonstrates a creative way to replace and keep a renewable energy resource local while providing benefits to the City beyond energy generation. This facility will help Loveland Water and Power exceed its renewable energy requirements from the State, delay future capital expenditures, and can even be used for solar education in the community.

— Gretchen Stanford, City of Loveland Foothills Solar Project

Gretchen Stanford, City of Loveland Foothills Solar Project

The solar looks great. We have noticed that many of our tenants are proud to work in a building that is solar powered and have included it in their monthly newsletters. Pretty exciting stuff.

— Aaryn Manning, Westbrook Development Partners

Aaryn Manning, Westbrook Development Partners

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