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

Get top-rated, practical training

Close-up of "Apartment for rent" sign in red text on black background in front of blurred building

Trump Administration Could Effectively End Housing Voucher Program

Federal officials are eyeing major cuts to the Section 8 program that helps millions of low-income households pay rent.

April 21, 2025 - Housing Wire

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.

April 30, 2025 - Diana Ionescu

Ken Jennings stands in front of Snohomish County Community Transit bus.

Ken Jennings Launches Transit Web Series

The Jeopardy champ wants you to ride public transit.

April 20, 2025 - Streetsblog USA

Close-up of white panel at top of school bus with "100% electric" black text.

Driving Equity and Clean Air: California Invests in Greener School Transportation

California has awarded $500 million to fund 1,000 zero-emission school buses and chargers for educational agencies as part of its effort to reduce pollution, improve student health, and accelerate the transition to clean transportation.

April 30 - California Air Resources Board

Aerial view of Freeway Park cap park over I-5 interstate freeway in Seattle, Washington at night.

Congress Moves to End Reconnecting Communities and Related Grants

The House Transportation and Infrastructure Committee moved to rescind funding for the Neighborhood Equity and Access program, which funds highway removals, freeway caps, transit projects, pedestrian infrastructure, and more.

April 30 - Streetsblog USA

"No Thru Traffic - Open Streets Restaurants" sign in New York City during Covid-19 pandemic.

From Throughway to Public Space: Taking Back the American Street

How the Covid-19 pandemic taught us new ways to reclaim city streets from cars.

April 30 - Next City