California state mandates that all new homes built starting in 2020, are now formally part of the state’s building code. This requirement is only for new homes built in California to include solar electric systems. This exciting mandate is the first of it’s type in the United States, making California the first state in the nation to mandate solar-energy installations on most single-family homes and multi-family residential buildings.
The Mandate

New Home Solar Mandate
This solar mandate has brought many questions to our Educational Showroom. Many people are under the misconception of what the mandate actually is. Some misinformation states that all homes in California have to have solar panels by 2020. Some people are under the impression that any homes that are sold after 2020 must have solar panels installed. The reality is that only new home developers need to be concerned with the new building code. Current home owners do not need to rush out and install solar to keep their homes to code. The clarification of new building code can be found in the state’s 2019 Title 24, Part 6, Building Energy Efficiency Standards. This code specifies that most new single-family homes and most multi-family residential units, including apartments, condos, and duplexes, will need to be outfitted with solar electric systems starting on January 1, 2020. The new code also helps to incentivize energy storage and include energy efficiency upgrades that will help slash energy use in new homes by more than 50%.
The Basics of the New Code

Solar on Home
One of the first aspects to recognize is that this new building code mandate only applies to residential buildings under 3 stories tall. Additionally, the solar mandate will be climate-zone specific and based on the floor area of the dwelling unit. The solar PV system must then be sized to net out the annual kilowatt-hour energy usage of the dwelling. Common areas in multifamily units are not calculated into this equation. In addition, the solar standard encourages demand-responsive technologies, including battery storage and heat pump water heaters as well as improvements to the buildings thermal envelope through high-performance attics, walls, and windows.
The 2019 code was developed based on a mixed-fuel home, meaning the homes are still going to be dependent on some level of natural gas. This suggests that the building mandate does not demand that all homes become 100% dependent on clean energy. It also means that if a homeowner decides to purchase an EV car and charger or purely increases their electrical energy usage, they do not need to install more panels. The minimum required by code will be installed at time of purchase. A homeowner could always make the choice to install more panels to become more dependent on green energy or to control other rising energy costs, but it would not be legally imperative to do so.
City or Municipal Mandates Along With California State Mandates

Multi-residential Solar Project
One truly important aspect to consider when it comes to this new building code is that is this only the state building code. Each county, municipality, or city may create further solar energy mandates. In fact, to date, there are 16 local governments that have approved energy standards for newly constructed homes in their communities already, including the cities of Santa Monica, Del Mar and Fremont. What this means is that state building code is just one piece in the larger puzzle. Currently, most developers (and potential new home buyers) only need to be concerned with state-level mandates that come in to play in January 2020. However, like most trends in city planning and development, state mandates typically are closely followed by rules, regulations, and city driven mandates. This means that as we work with developers as we come closer to the mandate implementation, we need to be mindful that the minimum solar kilowatt system the state mandates may not be the same that the city mandates. And as developers move forward, they well know they both city, state and any other municipal codes must be answered to.
Preparing for 2020 California State Mandates
As a local solar installer, it is vital that we understand the mandates that are coming to the table. For in-house solar installers, such as Del Sol Energy, our solar design and engineering departments must be aware of the energy mandates. As we work with city and local municipalities, part of the process is to obtain building permits for the installation. The only way we can obtain those permits and pass any sort of inspection is to ensure our installs answer to all city codes. If you are beginning to explore solar energy, take the time to ask about these mandates and how they may impact your new home purchase. For solar installers, such as Del Sol Energy, knowing these mandates is part of how we provide excellent customer service and quality installs. As much as solar is seen as a luxury upgrade for homeowners, this new building code mandate is a clear reminder that solar is no longer just a construction option or home upgrade – it is all part of the plan for a cleaner California.
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