Backyard Housing Boom: L.A. Sees Record Level of ADU Construction After Easing Restrictions

If you've driven through Los Angeles recently, you may have noticed a glut of new-construction projects taking place on residential properties.But many of these projects aren't brand-new homes. Instead, they're what's often referred to as accessory dwelling units: construction projects meant to expand an existing property by adding square footage through a garage conversion or a backyard addition.In L.A., in particular, the ADU market has exploded in recent years. A new report from the University of Southern California's Lusk Center for Real Estate found that Los Angeles County completed a record 10,230 ADUs in 2025. That's a massive increase from 2018, when just 1,623 units were built.While overall housing production across the county dipped slightly in 2025 to 27,293 units (down from 28,498 in 2024), the USC report found ADU construction continued to climb. ADUs accounted for 37.5% of all newly certified housing units last year, marking the highest share recorded in the nearly 10 years USC has tracked the data.Why ADUs are boomingFor years, restrictive zoning laws, complex permitting hurdles, and strict development limits made adding a secondary unit to a single-family housing un...