California Coding

California building codes


This summer California updated a good number of their building codes, including their Building Energy Efficiency Standards, commonly known as Title 24. While this happens every three years, this is the first year the energy code and the rest of the codes are on the same cycle. This cycle’s iteration of Title 24 covers some groundbreaking territory. What does that mean for California, and why should the rest of us care?

“As California goes, so goes the rest of the world,” says Erin McConahey, principal, ARUP, an independent firm of designers, planners, engineers, consultants and technical specialists. She’s speaking about California’s unique position in the world. A huge state, its gross domestic product (GDP) was tied for eighth place in the world in 2013, with forecasters predicting that it will likely move up and pass Italy and the Russian Federation. California is a bear, and when it roars the world listens.

So what does that mean for building codes? Most of the country adopts its energy codes based on ASHRAE 90.1 recommendations. The two entities are on separate cycles, but many of the same people work on both. “ASHRAE 90.1 is on a schedule that’s half a cycle off from Tittle 24,” says Mark Hydeman, PE, Fellow ASHRAE. “In general the California Commission accepts 90.1 as a well-vetted measure and often takes recommendations straight from it.” And visa versa. There are some interesting new standards in the latest Title 24 that the rest of the country should keep an eye on.


Many of the changes in the new Title 24 focus on lighting, both indoors and out. “Some of the best practices that we’ve been using for dimmable lighting and daylight responsiveness have now been adopted into the code,” says Erik Ring, PE, LEED Fellow, LPA, Inc. According to an article in LPA Blog ( by Jim Montross, “All indoor lighting will be controlled with an occupant sensor, automatic time switch control or other control to automatically shut lights off when the space is unoccupied. It is now mandatory to use sensor controls in offices less than 250 square feet, multipurpose rooms less than 1,000 square feet and conference rooms and classrooms of any size.”

Montross continues, “Luminaires providing general lighting that are in the skylit daylit zones or sidelit daylit zones will be provided with automatic dimming controls to reduce the light output in response to available sunlight, to maintain a constant light level in these daylit zones.”

Outdoor lighting must be controlled as well. Motion sensors will dim unused lights to 50 percent. Ring predicts that this may cause tension between efficiency and safety. “This will generate some challenging conversations.”


Demand response is an important part of the new code. This allows a building to reduce energy consumption when demand is extremely high, raising efficiency while reducing rolling brownouts. According to a white paper by Daintree Networks, “a networked building control system can dynamically act on a signal over the Internet from a utility company without any human interaction, delivering efficient and consistent results. The revised Title 24 code requires all commercial buildings over 10,000 square feet to have automated demand response capabilities in their lighting systems regardless of space type. This lighting system must be capable of receiving and automatically responding to standards-based messaging, such as OpenADR, to reduce lighting power by at least 15 percent below the building’s maximum lighting power during peak demand times.”

HVAC must also be plugged into this smart grid.


Advances in the building envelope, HVAC and lighting have decreased energy usage dramatically. Now it’s the lowly plug’s turn. Daintree Networks states that office plug loads and task lighting are now, “the largest power density loads in most office buildings with office equipment being the third highest contributor to electricity usage in California buildings. This electricity use will continue to increase as more personal computers and other electronics are introduced into office spaces.”

To combat this energy suck, Title 24 mandates that 50 percent of all outlets must be on a separate circuit that could be switched off when the building is not in use. “We considered this measure in the 2010 ASHRAE 90.1 standard,” says Hydeman, “but we couldn’t show cost savings. Now that California has adopted it I suspect it will be part of the 2016 standard.”


Another aspect of Title 24 that Hydeman and his colleagues are watching closely is the provision for photovoltaic (PV) systems. The new code demands that if a space is larger than 10,000 square feet then 15 percent of the roof must be reserved for future PV systems. “This will add cost, because you’ll have to pull conduit all the way to the roof and build the roof strongly enough to support the PV systems,” says Hydeman.

“This may impact cost and design,” says Ring. “We don’t know yet. It’s so new.”


The California Energy Commission states that their energy efficiency standards have saved Californians more than $74 billion in reduced energy bills since 1977. Hydeman further points out that these measures helped the state avoid building 15,000 MW of power plants, and that California has the lowest per capita energy use in the U.S. Still, adhering to these codes will cause some initial pain.

“The lighting controls will probably add between $5 and $7 a square foot,” says Ring.

But here’s the rub: enforcement is spotty, and for those who want to comply the new software is buggy. “Federal and state building departments are strapped,” says Hydeman. “They are more focused on things that will fall down, blow up or catch fire.”

Still, the codes have pushed efficiency forward, and net zero is probably not far behind.

“The U.S. Department of Energy has stated a strong preference to have commercial buildings be net-zero by 2050,” says McConahey. “It’s not out of the realm of possibilities.”

This article originally appeared in the issue of .

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