California Sees Spike in ADU Permits

Homeowners in the state are eagerly taking advantage of new laws allowing them to build additional housing units, making a small but significant impact on the housing supply.

2 minute read

May 29, 2023, 7:00 AM PDT

By Diana Ionescu @aworkoffiction


Small grey accessory dwelling unit cottage in California backyard

City of Salinas / Accessory dwelling unit

The liberalization of laws surrounding the construction of accessory dwelling units (ADUs), also known as granny flats, is starting to make a significant dent in California’s housing crisis. While far from a panacea, the flurry of permits issued for ADUs signal that homeowners across the state are eager to take advantage of the opportunity to build an extra housing unit on their property.

As Erica Werner explains in The Washington Post, “More than 23,000 ADU permits were issued in California last year, compared with fewer than 5,000 in 2017 — which was around when ADU permitting began to take off thanks to legislative and regulatory changes in the state.” Los Angeles issued 7,160 of those permits, while only issuing 1,387 permits for single-family homes in the same time period.

Despite the high cost of ADU construction—the average unit runs roughly $300,000—“a study from the NYU Furman Center found that ADUs are being built not in the wealthiest neighborhoods, but more often in low- to middle-income areas, and often in places with relatively good access to jobs.” According to study author Christopher Elmendorf, “‘That’s consistent with the theory that this is a viable form of development in places that you may not’ otherwise be able to easily build.” David Garcia, policy director for the Terner Center for Housing Innovation at the University of California at Berkeley, says the speed at which Californians are applying for ADU permits signals “a pent-up demand from homeowners to want to do more with their land.”

Sunday, May 21, 2023 in The Washington Post

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

Red 1972 Ford Pinto with black racing stripes on display with man sitting in driver's seat.

Analysis: Cybertruck Fatality Rate Far Exceeds That of Ford Pinto

The Tesla Cybertruck was recalled seven times last year.

2 hours ago - Mother Jones

Close-up of park ranger in green jacket and khaki hat looking out at Bryce Canyon National Park red rock formations.

National Parks Layoffs Will Cause Communities to Lose Billions

Thousands of essential park workers were laid off this week, just before the busy spring break season.

February 18, 2025 - National Parks Traveler

Paved walking path next to canal in The Woodlands, Texas with office buildings in background.

Retro-silient?: America’s First “Eco-burb,” The Woodlands Turns 50

A master-planned community north of Houston offers lessons on green infrastructure and resilient design, but falls short of its founder’s lofty affordability and walkability goals.

February 19, 2025 - Greg Flisram

Screenshot of shade map of Buffalo, New York with legend.

Test News Post 1

This is a summary

0 seconds ago - 2TheAdvocate.com

Red 1972 Ford Pinto with black racing stripes on display with man sitting in driver's seat.

Analysis: Cybertruck Fatality Rate Far Exceeds That of Ford Pinto

The Tesla Cybertruck was recalled seven times last year.

18 minutes ago - Mother Jones

test alt text

Test News Headline 46

Test for the image on the front page.

March 5 - Cleantech blog