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

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

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Hot air balloons rise over Downtown Boise with the State Capitol building visible amidst the high rises.

The Five Most-Changed American Cities

A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.

April 23, 2025 - GoodMigrations

People biking along beach path with moored ship in San Diego, California.

San Diego Adopts First Mobility Master Plan

The plan provides a comprehensive framework for making San Diego’s transportation network more multimodal, accessible, and sustainable.

15 minutes ago - SD News

Sleeping in Public

Housing, Supportive Service Providers Brace for Federal Cuts

Organizations that provide housing assistance are tightening their purse strings and making plans for maintaining operations if federal funding dries up.

1 hour ago - KSL

Conductor walks down platform next to Amtrak train at station in San Jose, California.

Op-Ed: Why an Effective Passenger Rail Network Needs Government Involvement

An outdated rail network that privileges freight won’t be fixed by privatizing Amtrak.

2 hours ago - Streetsblog USA

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.