Climate change is a global challenge often addressed locally. Local governments influence community development through land use controls. Their decisions on housing density, location, and building standards significantly impact climate—buildings contribute nearly 40% of U.S. carbon emissions, and personal vehicles account for 10% of global CO2 emissions. Increasing urban density is crucial for reducing greenhouse gas emissions.
There is growing agreement among policymakers and scholars that relaxing zoning laws to encourage higher density, while tightening building efficiency standards, can reduce emissions and alleviate housing shortages across the U.S.
“Solving carbon emissions in our built environment requires more than the neoliberal deregulation prevalent in current discourse,” the authors of a new paper from Vanderbilt argue. “Land use and building code reforms are essential but should be nuanced.”
Strong connection
Fewer restrictions might boost development but won’t necessarily lead to greater density. For example, allowing accessory dwelling units or eliminating single-family zones could increase urban development, but might also spur more development in suburban or exurban areas.
“Regulatory reforms that marginally increase density might worsen emissions if they create isolated pockets of density far from jobs and shopping,” the paper notes.
In some metropolitan areas, looser zoning can lead to growth from the outside in, reducing density and failing to cut emissions. The paper cites Houston, Phoenix, and Nashville as examples of lightly zoned, yet not particularly dense cities.
Regional differences
The impact of zoning reform on density varies by local and regional context. Deregulation doesn’t necessarily increase density, despite many reformers’ claims.
Green standards like LEED Certifications aim to cut emissions but can raise construction costs and housing prices. This is problematic if low-carbon areas become so expensive that development shifts to high-carbon areas instead.
Location is crucial for greenhouse gas emissions. Homes in the Midwest may need more energy for heating and cooling than in California. Some energy grids are less decarbonized than others.
The biggest emissions difference is between suburbs and urban cores. San Diego’s suburbs produce more household carbon emissions than Memphis’s urban core.
Boosting efficiency
Green building requirements boost energy efficiency and reduce emissions in individual homes, but they can also increase housing costs, potentially leading to a net negative effect.
“Even well-intentioned green building codes can increase carbon emissions if they push people to more carbon-intensive areas,” the authors explain.
Rather than simply relaxing zoning restrictions or implementing green building standards, Serkin advocates for climate-conscious zoning at the local level, supported by state and federal resources.
Recommendations for local governments depend on whether the municipality is high- or low-carbon.
Encouraging growth
Low-carbon areas like urban cores should encourage growth by loosening some zoning regulations while ensuring that compliance and approval processes do not delay projects. Proposals include setting maximum unit sizes, density minimums, using eminent domain to assemble land for development, and increasing government development activity.
For high-carbon places like suburbs and exurbs, more aggressive regulations are needed. Suggestions include stricter codes, energy impact fees, agricultural land protections, and conservation easements.
Universal strategies include streamlining the siting of renewable energy infrastructure, eliminating parking requirements and single-use residential zoning, adding walking and biking infrastructure, and preserving vegetation.
State governments can support local efforts by investing in mass transit instead of highways that promote suburban commuting.
“Specific strategies vary by place but aim to make other forms of transportation easier and more appealing than driving,” the authors say.
The paper also advocates for urban growth boundaries, such as greenbelts, to promote development within cities and preserve land outside for agriculture or low-intensity uses, often requiring state involvement.
Loosening regulations
It calls for states to loosen environmental regulations in central cities to encourage development, emphasizing that these reforms should not relax environmental rules statewide.
The paper highlights the power of zoning in combating climate change, as it shapes where people live and work. It warns that the dominant responses—deregulation to promote density, green building codes, and statewide land use controls—do not account for the differences between low- and high-carbon environments.
“Local governments need place-specific prescriptions,” the authors conclude. “This nuanced approach recognizes that we cannot deregulate our way out of the climate crisis but need tailored zoning options to increase density and reduce emissions.”
