California Leaders Strive for Sustainable Infill Development to Address the State’s Climate and Housing Challenges

As California continues to struggle with rampant homelessness and chronic climate disasters, environmentalists and affordable housing advocates are pushing for infill housing to solve both issues in tandem. 

Recently, controversy has swelled around California’s zoning policies and housing availability. A study from UC Berkeley found that 95.8% of residential land in California is zoned for single-family housing. In a state that had the worst rates of homelessness in the country in 2024, housing advocates and environmentalists point to these restrictive zoning policies as a primary barrier to new, sustainable housing developments.

“The zoning is atrocious,” said Professor Miriam Greenberg, a professor of urban sociology at the University of California Santa Cruz. “When people are pushed further out from their schools and jobs … we see these really unsustainable, sprawling metro areas…there’s the severe environmental impacts of sprawl on the basis of greenhouse emissions, and of fire in our state.”

Current California greenhouse gas emissions inventory from California Air Resources Board’s latest yearly report. Transportation produces 39% (144.7 mmt CO2e) of all of the state’s emissions.

Indeed, the sprawl of single family homes is a leading cause of California’s environmental degradation. With more people living further outside the city, commute distances have vastly increased, and the resulting upsurge in vehicle travel produced 144.7 million tons of carbon in 2022. Sprawl also means that more homes are brushing up against rural, arid landscapes, putting Californians at greater risk for wildfires. Since 2000, California has suffered 35 mega-fires responsible for over 40 billion dollars in damages.

Now, in the wake of the January 2025 blaze that ravaged Los Angeles, advocates are striving for innovative housing policy that reforms California’s approach to development.

“The loosening of zoning is important, but housing also needs regulations to ensure affordable development goes into these re-zoned spaces,” explained Greenberg. “The de-commodification of housing to the greatest extent possible, the preservation of already existing housing, and strong laws to protect tenants, are equally important.”

Reformed housing policies also need to be environmentally sustainable as well. To reach these ends, cities around the state are revitalizing their neighborhoods with infill housing.

Infill housing is the development of underutilized and/or vacant spaces in pre-existing development areas – such as former industrial sites or vacant parking lots. By focusing on developing in or near city centers, infill housing development significantly cuts transportation distances, making walking and biking more accessible and desirable.

California’s Affordable Housing and Sustainable Communities (AHSC) initiative is one of the leading programs creating affordable infill housing that cuts sprawl and reduces emissions.

In the last ten years, the AHSC has invested nearly four billion dollars in cleanup and construction efforts. In doing so, the AHSC has helped build over 15 thousand new homes and avoid 4.4 million metric tons of greenhouse gas emissions. 

“Infill housing is at the forefront of this program” explained Amar Cid, Deputy Director of Community Investments and Planning for California’s Strategic Growth Council. “We’re seeing hundreds of new housing come online … and it’s amazing to see affordable housing with community-centered sustainable transportation options to reduce greenhouse gas emissions.”

According to Cid, a vital element of the AHSC’s success is tenant input.

“There’s significant attention around this program, and rightfully so, to ensure this program is providing a direct and meaningful benefit to the communities,” Cid explained. “The AHSC program teams have worked tirelessly with community advocates, housing advocates, transportation advocates, and the public, to really bring some transformative and iterative processes to light.”

Additionally, the long term success of the AHSC has been forged through the collaboration of different developers addressing the root of community issues together. 

“We're addressing affordability and housing needs while ensuring this work is done in a sustainable and holistic way. By partnering housing and transportation together we address core concerns that people are grappling with,” said Cid. 

As the AHSC continues to make progress in sustainable housing in cities around the state, local elected officials are playing a key role in adopting improved local zoning rules and regulations.

In Emeryville, a small city situated on the eastern shore of the San Francisco Bay, city councilors are implementing their 2023-2031 Housing Element and Climate Action 2.0 Plan. The plans set ambitious goals of constructing 3,687 new housing units and reducing 80% greenhouse gas emissions by 2031 and 2050 respectively.  

So far, the city has made significant progress on the housing front. After successful cleanup efforts in brown fields – abandoned industrial sites where toxic waste has built up – city councilors have approved the construction of 1,815 affordable housing units in their place.

More affordable housing means that more people – of all incomes – have been able to move into Emeryville, which has led to more people attending Emeryville public forums to express their desires for greener public infrastructure. 

“It’s been very exciting over the past five to ten years,” explained Emeryville City Council Member Matthew Solomon, a member of Run on Climate’s Local Climate Policy Network. “It’s good to live in a growing city, and we’ve been able to use new housing development as a tool to get safer bike infrastructure, more parks, and more money for our affordable housing programs.” 

These improvements have made Emeryville one of the most environmentally friendly cities in the California Bay Area. According to the city’s most recent carbon footprint inventory, Emeryville had the lowest per-household carbon footprint in the region.

Estimations of Emeryville’s emissions reductions by 2030 according to CoolClimate

The key to Emeryville’s housing and climate progress has been local leaders’ ability to bridge the gap between building requirements and strong climate regulations.

“It’s taken work from a lot of advocates, from a lot of policy organizations like Run on Climate, who are able to make that connection that housing is very important on its own, but it's also very important to addressing the climate challenge.”

Recognizing the connection between climate change and affordable housing will aid California’s progress towards its goal of carbon neutrality by 2045. As more advocates come together, officials are confident that the state is heading in the right direction. 

“We'll continue to have very impactful community engagement that leads to easier funding structures, easier opportunities to engage with developers and community, and coordination with local entities,” said Cid.