Building Boom: Study Reveals Effects of California's 2016 Accessory Dwelling Units Law

Permits have shot up after California passed a landmark law in 2016 to make it easier to permit and construct accessory dwelling units (ADUs).

1 minute read

December 25, 2017, 1:00 PM PST

By James Brasuell @CasualBrasuell


The Terner Center for Housing Innovation at UC Berkeley has released a new brief [pdf] that "discusses the benefits of ADUs for supply-restricted and cost-burdened regions, and examines data from California’s largest cities (and a handful of other jurisdictions) to measure how much interest in, and production of ADUs has increased in the past year."

"The results are telling: across the board cities are seeing significant increases in ADU applications, with many cities doubling, tripling, or even quadrupling their totals from 2016," according to a post announcing the new report. For instance, Los Angeles saw 90 ADU applications in 2015. In 2017, that total reached 1,980.

The policy brief includes recommendations for removing some of the remaining barriers to ADU permitting and construction in cities around the state.

Thursday, December 21, 2017 in Terner Center for Housing Innovation

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

"Altadena - Not For Sale" yard sign in front of burned down house after Eaton Fire in Altadena, California in January 2025.

Half of Post-Fire Altadena Home Sales Were to Corporations

Large investors are quietly buying up dozens of properties in Altadena, California, where a devastating wildfire destroyed more than 6,000 homes in January.

July 7 - Dwell

Dense multistory residential buildings in hilly San Francisco, California.

Opinion: What San Francisco’s Proposed ‘Family Zoning’ Could Really Mean

Mayor Lurie is using ‘family zoning’ to encourage denser development and upzoning — but could the concept actually foster community and more human-scale public spaces?

July 7 - The San Francisco Standard

Blue self-driving Ford Transit van shuttle in Jacksonville, Florida.

Jacksonville Launches First Autonomous Transit Shuttle in US

A fleet of 14 fully autonomous vehicles will serve a 3.5-mile downtown Jacksonville route with 12 stops.

July 7 - Smart Cities Dive

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.

Associate/Senior Planner

Gallatin County Department of Planning & Community Development

Senior Planner

Heyer Gruel & Associates PA