What is Urban Sprawl?

Urban sprawl is low-density, car-dependent development that spreads homes, stores, and workplaces far apart—usually as single-family houses on the edges of a city or town. It happens when a region grows outward instead of upward.

In California, sprawl shapes daily life for millions of people: how long you sit in traffic, what you pay for gas and insurance, and how close your home sits to wildfire risk.

What causes urban sprawl?

Sprawl usually starts with good intentions—cities trying to house a growing population, and families looking for more space at a price they can afford. But for decades, local zoning rules made it far easier to build a large house at the edge of town than to build near jobs and transit. Because of that, cities grew in size rather than becoming more dense, leading to sprawling development that can have adverse effects on the people living within it.

How does urban sprawl affect Californians?

The negative effects of urban sprawl include:

• • Longer commutes and more time stuck in traffic
  • Higher costs for gas, car ownership, water, and energy
  • More air and climate pollution, which worsens asthma and heart disease
  • More traffic deaths and injuries
  • Greater wildfire risk when homes are built into wildland areas
  • Loss of farmland, open space, and wildlife habitat
  • Higher costs for taxpayers, who pay to extend roads, pipes, and emergency services further out
  • Deeper economic and racial inequities
  • Less community cohesiveness and more social disconnection

How does sprawl drive up wildfire risk and insurance costs?

When development pushes into the wildland-urban interface—the zone where neighborhoods meet undeveloped wildland—more homes and more people end up in the path of fire. Between 2020 and 2022, more than 80% of new homes built in California went up in high fire-risk areas. Phys.org

That risk lands on household budgets. Insurers price it in, and in the highest-risk areas, some stop writing policies altogether. Where we build is now one of the biggest factors in what Californians pay to insure a home.

What is California doing about urban sprawl?

Most of the tools that decide whether a region sprawls are local. Cities and counties set zoning and subdivision rules, draw urban growth boundaries, offer density bonuses, and cast the votes that approve or reject individual projects. When a city makes it legal to build apartments and townhomes near jobs, schools, and transit, growth has somewhere to go besides outward.

To solve the problem of urban sprawl, local governments must implement better planning policies that concentrate growth and prevent sprawling into rural areas. One main strategy is to make it easier to build homes where roads, water, schools, and transit already exist—an approach often called “smart growth” or infill development. 

“Smart growth” advocates for compact building designs, walkable neighborhoods, accessible transportation options, and other sustainable planning improvements. Sprawl-prevention policies may include land development measures, such as zoning and subdivision regulation, permit limits, and urban growth boundaries.

At the state level, SB 79 took effect July 1, 2026, allowing more homes near major transit stops in the eight California counties with the most passenger rail service.

Does environmental review cause urban sprawl?

While opponents of environmental review like to argue this, the real answer to “does environmental review cause urban sprawl” is no—here’s why.

The California Environmental Quality Act (CEQA) requires new development to account for its health and safety impacts before it gets built, and gives the people who live nearby a say. That’s what makes a developer plan evacuation routes for homes going up in a fire-prone area, and what keeps an oil company from drilling next to your neighborhood without public notice.

Sprawl wasn’t caused by that review process. It was caused by decades of local rules that made low-density edge development the easiest thing to build.

In June 2025, the legislature rushed AB 130 and SB 131 through as part of a budget deal, creating sweeping new exemptions from environmental review. EnviroVoters opposed both. The exemptions reach well past housing—covering “advanced manufacturing” projects from data centers to open-pit mines—and froze updates to California’s building code for five years, the same code that sets the fire-resistance and energy-efficiency standards that make homes and buildings safe, healthy, energy-efficient, and cost-effective for the people who live there.

Cutting community review removes the check that catches dangerous projects wherever they’re proposed, including sprawl developments in high fire-risk areas. And it takes away the voice of the people living next to these projects, erasing their ability to have a say in what gets built near them. In 2026, we’re pushing for clean-up legislation to restore the protections SB 131 stripped away.

What can you do about sprawl in your community?

Sprawl gets decided locally, in city council and county planning meetings that rarely make the news. Here are three steps you can take to prevent the effects of urban sprawl in your community:

1. Show up or write in when a project comes up for a vote in your city or county planning meetings, for both good projects that densify development or bad projects that worsen the effects of urban sprawl. 
2. Support local government efforts to acquire and protect ecologically critical areas and expand open-space protections where you live. 
3. Watch how your state legislators vote on housing and climate bills—those votes set the rules your city has to follow.

See how your legislators voted on climate. → Look up your representatives on the EnviroVoters Scorecard

Sources

• • UC Irvine: California wildfire damage risk map
  • CAL FIRE Office of the State Fire Marshal: Building in the Wildland
  • Nature Education: The Characteristics, Causes, and Consequences of Sprawling Development
  • Smart Growth America
  • California Legislative Information: SB 79
  • FACT SHEET: Impact of Wildfires on – Insurance Non-Renewals and Availability 

Originally published March 2, 2021.