That word we’re using doesn’t mean what we think it means: Examining the greenhouse gas emissions and marginal abatement costs of Zero Net Energy homes in California

California has long been at the leading edge of building energy regulations. In 2008, in response to AB 32 and in an effort to reduce greenhouse gas emissions from the building sector, California adopted the ambitious goal of requiring all new single-family and low-rise residential construction to be designed to achieve Zero Net Energy (ZNE) performance beginning in 2020. As a result, the state embarked on a decade of research and market transformation activities intended to make ZNE a cost-effective reality for residents. In 2018, the California Energy Commission announced that the long-anticipated mandate for ZNE homes would not take effect; instead, an emphasis on buildings that “bring value to the grid” will define the approach to future iterations of the state’s building energy code, known as Title 24. Was this the right decision for reducing greenhouse gas emissions? This discussion will examine the differences in statewide emissions for ZNE homes and houses built under California’s adopted 2020 energy code. Additionally, marginal abatement costs are examined for homes designed under the newly adopted code, allowing comparison to other forms of carbon abatement. The findings reveal the contribution of different fuel types on residential emissions, and how various regulations, in addition to California’s definition of ZNE itself, effect the greenhouse gas abatement potential of this housing type.

Bio: Ben White is a LEED-accredited, licensed architect and a Ph.D. candidate in the Transportation Technology and Policy program, where he researches California energy policy and the built environment. While attending UC Davis Ben has been lead author of two CEC-sponsored studies of the nation’s largest planned ZNE community, West Village, and was the project manager for the campus’s first entry in the US DOE-sponsored Solar Decathlon, where he managed ~400 students undertaking the design and construction of a ZNE home. Prior to attending UC Davis, Ben was involved in the design and construction of over one million square feet of commercial and educational space in southern California and was named Young Architect of the Year by the American Institute of Architects, San Diego chapter.  Ben earned a Master’s degree at UCSB’s Bren School of Environmental Science and Management, where he completed a thesis examining the feasibility of offshore wind energy development in the central California coast.