How Cities Can Support ADU Production

Although state-level laws are making it easier for homeowners to build accessory dwelling units, high impact and development fees remain a major barrier for many prospective ADU builders.

1 minute read

November 14, 2024, 8:00 AM PST

By Diana Ionescu @aworkoffiction


Craftsman-style two-story home with detached converted garage apartment accessory dwelling unit.

A detached garage converted to an accessory dwelling unit. | Sightline Institute: Missing Middle Homes Photo Library, CC BY 2.0, via Wikimedia Commons / Wikimedia Commons

While many states are liberalizing regulations related to accessory dwelling units (ADUs) to make ‘granny flats’ easier to build, “local governments remain the key gatekeepers when it comes to ADU liberalization,” writes Mike Koenig in HousingWire.

For Koenig, there’s still work to do to ensure property owners around the country can easily and affordably build backyard cottages or other add-on units on residential lots that can help gently increase density and improve housing affordability.

“As state legislatures continue to press municipalities to ease or remove ADU-related restrictions (13 and counting have done so), utility and other fees—collectively known as impact fees—move toward the center of pro-ADU policy discussions. That’s because impact fees can add up to more than enough to stifle ADU development.” Koenig recommends a few ways cities can ensure their regulations aren’t limiting ADU production, including prorating impact fees and waiving certain development fees.

Koenig points out that the higher density created by ADUs can bring long-term benefits to the community beyond housing affordability, including higher tax revenues. But while costs and other barriers remain high, “States and municipalities have come a long way in smoothing the paths forward for those who hope to add vital infill housing through ADUs.”

Monday, November 11, 2024 in HousingWire

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

High-rise apartment buildings in Waikiki, Hawaii with steep green mountains in background.

Study: Maui’s Plan to Convert Vacation Rentals to Long-Term Housing Could Cause Nearly $1 Billion Economic Loss

The plan would reduce visitor accommodation by 25,% resulting in 1,900 jobs lost.

April 6, 2025 - Honolulu Civil Beat

People sitting and walking in plaza in front of historic Benton County Courthouse in Bentonville, Arkansas.

Placekeeping: Setting a New Precedent for City Planners

How a preservation-based approach to redevelopment and urban design can prevent displacement and honor legacy communities.

March 28, 2025 - Emily McCoy

Rusty abandoned oil well and equipment with prickly pear cactus next to it in West Texas.

Using Old Oil and Gas Wells for Green Energy Storage

Penn State researchers have found that repurposing abandoned oil and gas wells for geothermal-assisted compressed-air energy storage can boost efficiency, reduce environmental risks, and support clean energy and job transitions.

March 31, 2025 - Pennsylvania State University

Two people on bikes riding down paved Burke-Gilman bike trail in King County, Washington on a sunny day.

Washington State Plans Ambitious ‘Cycle Highway’ Network

The state is directing funding to close gaps in its existing bike network and make long-distance trips more accessible.

6 hours ago - Momentum Magazine

Small green ADU cottage in lush backyard in San Jose, California.

Homeowners Blame PG&E for Delays in ADU Permits

The utility says it has dramatically reduced its backlog, but applicants say they still face months-long delays for approvals for new electrical work.

7 hours ago - San Francisco Chronicle

Large oak tree in meadow with sun filtering from behind it in Angeles National Forest.

Rethinking Wildfire Defense: How a Landscape Approach Can Protect Neighborhoods

Post-fire analysis of the Eaton Fire reveals that a landscape approach — including fire-resistant vegetation, home hardening, and strategic planning — can help reduce wildfire risk, challenging assumptions that trees and plants are primary fire hazards.

April 8 - ASLA The Dirt