So Now We Have ADU McMansions Popping Up Everywhere?

Accessory Dwelling Units (ADUs) were supposed to be an affordable, flexible answer to California’s housing crunch. But in areas such as Larchmont Village, “Sunset Park” in Santa Monica and similar neighborhoods, we’re seeing a new twist: “ADU McMansions”—oversized, luxury ADUs that feel more like mini-mansions than modest backyard cottages.

The ADU Boom: Recent Stats

• Statewide Growth: According to the 2024 California ADU Report by Cotta.ge, California cities approved over 24,000 ADU permits in 2023—almost double the number from 2020. Los Angeles leads the pack, accounting for about 30% of all ADU permits statewide.
• Share of New Housing: CA YIMBY’s 2024 retrospective found that 1 in 5 new homes built in California in 2023 was an ADU. In LA, it’s nearly 1 in 3.
• Neighborhood Impact: Larchmont Village and surrounding areas are seeing a surge in both detached and attached ADU applications, with many homeowners maximizing allowable square footage.

What’s Fueling “ADU McMansionization”?

• Lax Regulations: As CityWatch LA points out, recent reforms have loosened size restrictions and setbacks, making it easier to build larger and taller ADUs—sometimes nearly as big as the main house.
• Profit Motive: With high rental demand and rising property values, homeowners and developers are incentivized to build the largest, most luxurious ADUs possible, often reaching 1,000–1,200 sq ft and featuring high-end amenities.
• Design Creep: The original spirit of ADUs—modest, secondary units—can get lost. As AccessoryDwellings.org explains, property owners often push the limits, resulting in “backyard homes” that rival new single-family residences.

Are We Solving the McMansion Problem—or Making It Worse?

• Mansionization Redux: ADUs were meant to provide gentle density, but the trend in Larchmont Village is starting to echo the “mansionization” debates of the 2000s, with oversized new structures replacing classic bungalows.
• Community Concerns: Locals worry about changing neighborhood character, increased congestion, and the environmental impact of larger buildings and less green space.
• Policy Gaps: As CityWatch LA notes, enforcement of design standards and size limits is inconsistent, allowing this new wave of “McMansion” ADUs to flourish.

A Backyard ADU Bigger Than the Front House?

ADUs are still a vital tool for adding housing in neighborhoods like Larchmont Village. But without thoughtful regulation and community engagement, the rise of “ADU McMansions” could undermine the benefits—potentially making the original problems even worse.