A California Change-Up

A California License Plate Listed for Jan 2020
Published On
Sep 20, 2019

As it does every three years, California has updated its energy code, called Title 24, Part 6. The new code was adopted on May 9, 2018, and goes into effect Jan. 1, 2020. Many parts of the code changed, affecting residential and nonresidential buildings. This is important to estimators working in California but will also affect estimators working in states that adopt similar codes. The following is a partial list of the new requirements.


Residential projects will be mandated to have solar photovoltaics installed on new ground-up construction of three habitable stories or less from grade. The system’s size will be based on an equation in the code that includes the residence’s size and location. The average system size across California’s 16 climate regions would be 3.38 kilowatts (kW), with the smallest model system sized at 2.7 kW in San Diego and the largest sized at 5.7 kW in Palm Springs.

Exceptions to these requirements include buildings with little roof space, zero lot area and obstructions to the sun, such as tall buildings or protected trees. The solar panel requirement alone will not get new homes to California’s net-zero mandate by 2020. However, changes in the code for lighting, walls, attics, HVAC and plumbing will help close the gap.

There are complaints that the additional costs added to new homes will hurt the housing market. In response, the energy commission calculates that, based on a 30-year mortgage, the standards will add about $40 per month for the average home, but they will save consumers $80 per month on heating, cooling and lighting bills.

It is important to note that are two new energy polices: the Renewables Portfolio Standard (RPS) and Net Energy Metering rules (NEM). The RPS rules require utilities to get 50% of their electrical resources from renewable sources by 2030, which will contribute to the overall net-zero requirements.

I see the NEM rules as a compromise with the utility companies. Residential rooftop-solar generation is limited to be no more than the home would consume on an annual basis. If it does create a surplus, it will only be credited at a rate much lower than the retail cost.


The lighting-power allowances in the nonresidential category have been reduced 29% to 37%, depending on which of the two calculation methods is used. In part, these reductions are based on the assumption that all new construction, alterations and additions will use LED lighting exclusively. More energy savings are expected from rules encouraging more light from outdoors, including clerestory fenestration, horizontal slats and light shelves (and yes, I had very little idea what any of those were until I looked them up). An example of the complete building method would be a grocery store allowed 0.95 watts per square foot for all of the store’s lighting. The area category method specifies how much energy can be used for specific areas in a building and has been significantly changed for areas such as museum displays, dining areas, video conferencing, beauty salons and auditoriums.

Several minor revisions to the lighting- control rules are designed to clarify the requirements. New language requires separate controls for lighting fixtures in daylight, skylight, primary and secondary sidelit zones. An exception was added for outside lighting sources that are blocked for a significant amount of time, which is 1,500 hours per year between 8 a.m. and 4 p.m.

The demand-response requirements have been updated. If you are not familiar with this, the lighting controls must all be networked to a lighting control panel, which can be accessed through a utility company network. During peak-use times, the utility company can instruct the lighting control panel to reduce lighting loads by a certain percentage. The new code references specific communication protocols to simplify and secure a two-way information exchange. The new standards are OpenADR 2.0a or OpenADR 2.0b Virtual End Node (VEN) or certified by the manufacturer as being capable of responding to a demand-response signal from a certified OpenADR 2.0b VEN. The changes also define mandatory communication protocols, consisting of BACnet, ethernet, Wi-Fi, Zigbee or hard-wired.

A new section has been added to define the interactions between all control devices to ensure that the entire system works as a whole. Also, new rules for additions, alterations and repairs have been added. All projects that change 10% or more of the lighting fixtures in an enclosed space must comply with one of three options.

As you can see, the rules are complex. Unfortunately, electrical engineers often do not get all of these requirements on the bid documents. You are responsible for understanding the rules in your area and including those requirements in your bids.

About the Author

Stephen Carr

Estimating Columnist

Stephen Carr has been in the electrical construction business since 1971. He started Carr Consulting Services—which provides electrical estimating and educational services—in 1994. Contact him at 805.523.1575 or steve@electrical-estimating.com, and...

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