Are code-mandated zero carbon emissions in the future for California? There are many factors that are pushing buildings in that direction. The Building Energy Efficiency Standards (BEES) are requiring higher levels of energy efficiency with every code cycle. Jurisdictions up and down the state have been adopting reach codes that essentially ban natural gas in new buildings. The 2019 Energy Code requires solar for new single family and low-rise multifamily buildings, and nonresidential and multifamily residential buildings that are four stories and greater are expected to have code-required solar in 2030.

Now there is a potential path for that to be required sooner. Architecture 2030 is a non-profit organization that advocates for net zero energy and carbon neutral emissions in buildings. Their 2030 Challenge is a worldwide standard that provides goals and guidelines to get there. The 2030 Challenge includes guidelines for Energy Use Intensity (EUI) reductions by building type. Recently, in partnership with the American Institute of Architects (AIA) California, the organizations published 2022 Zero Code for California. Zero Code is an ambitious roadmap for near net zero carbon emissions in new nonresidential and multifamily residential buildings four stories and greater.


For jurisdictions that choose to adopt it, the Zero Code is intended to be a supplement to the 2022 Building Energy Efficiency Standards (BEES) (Title 24 Part 6). Similar to Tiers in the California Green Building Code, the Zero Code is written in clear code language to enable easy adoption. Because the Zero Code would be above and beyond the BEES, it would be considered a reach code. In order for local jurisdictions to enact and enforce a reach code, they must demonstrate to the California Energy Commission (CEC) that the standards are cost-effective. While it remains to be seen if the CEC will allow Zero Code to be codified, the publishers also suggests that Zero Code could be used by jurisdictions to incentivize builders.


The Zero Code would not require buildings to be more efficient than the 2022 Building Energy Efficiency Standards. Rather, it focuses on reducing carbon by eliminating carbon generation on site and by utilizing electricity from clean sources.

Combustion of natural gas generates carbon dioxide. In order to be net zero carbon emissions, the Zero Code prohibits the design and installation of gas appliances. The prohibition of gas is already codified through reach code amendments to the 2019 BEES in dozens of jurisdictions across the state.

Eliminating carbon is in line with the goals of the California Energy Commission and California Assembly Bill 32. CEC efforts outside of the Building Energy Efficiency Standards are evident in the increase of renewables and other clean energy in the state’s energy profile. The BEES themselves began requiring onsite solar for new low-rise residential and single family homes in 2019. The 2022 code is expected to make compliance easier for electric heat pump water heaters by changing the baseline from gas to electricity.

The Zero Code includes flexible renewable energy requirements. Options include onsite generation and/or offsite procurement. Offsite procurement makes it easier for new buildings to comply, including those with limited onsite renewable energy generation potential due to shading, obstructions, or other factors. In addition to a minimum two watts per square foot of appropriate roof area, projects can achieve this capacity through community solar or other sources that offer electricity from 100% renewable electricity sources.

The amount of solar required is determined through either a prescriptive or a performance approach. Zero Code’s Table 6.4 specifies prescriptive renewable energy requirements in kBtu/ft2-y (the common metric for Energy Use Intensity) for each of the CEC’s 16 climate zones and seven different building types. Alternatively, projects would be allowed to use the performance approach, which would utilize software programs approved by the CEC for demonstrating performance compliance with the Building Energy Efficiency Standards (such as CBECC or EnergyPro) to determine the amount of annual electricity required.

Regardless of what your goals are for energy efficiency or carbon reduction, whether complying with the Zero Code, an all-electric reach code, or just straight Title 24, energy compliance is complicated. Even the simplest of projects need an energy expert on their team; VCA Green is here to help. VCA Green’s team is comprised of CABEC Certified Energy Analysts (CEAs), Certified Energy Managers (CEMs), commissioning agents, Acceptance Test Technicians, and HERS Raters on staff who deeply understand Title 24 and zero emissions strategies.

For more information, contact Moe Fakih below.

Contributing Writer: Glen Folland, Director of Sustainability

Moe Fakih, Principal
VCA Green

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