Can you build an ADU in San Marino? Today, yes. This episode explains how California ADU law opened the door, what the rules now require, and how homeowners are using backyard homes to keep their families close in one of the most carefully preserved cities in Los Angeles County.

San Marino feels deliberately preserved, like everyone quietly agreed to keep it steady. That care is exactly what makes it such an instructive example of how state ADU law and thoughtful communities are learning to work together. We trace how California's reforms established a clear, objective path to approval, what written guidance from the California Department of Housing and Community Development clarified along the way, and how San Marino's own state-accepted housing plan now embraces accessory dwelling units as a meaningful part of meeting its RHNA housing goals. If terms like ministerial approval, ADU ordinance compliance, or HCD guidance have you wondering what they mean for your backyard, you will leave with a clearer map of the rules and how they protect both homeowners and the character of the community.

Most importantly, we get to what this means for your family. With San Marino home prices in multi-million-dollar territory, the biggest threat to family continuity is your kids getting priced out. We walk through two high-impact ADU strategies: a launch pad for adult children, and a house swap that supports aging in place while keeping grandkids close. We also cover the questions to bring to qualified tax and legal professionals around Proposition 13 and Proposition 19.

A well-designed ADU does not have to change the feel of a street. Done right, it preserves something more important: the ability for the next generation to stay.

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Thinking about building an ADU in California? The questions we hear every day: Can we build one? What about permits? Who can we trust to do it right?

That's Acton ADU. For 35+ years we've designed and built high-quality accessory dwelling units—long before backyard homes were a trend, and we handle the whole process, permits included.

Serious about an ADU? Start with the right team. Visit ActonADU.com or call (408) 539-1908—and let us know you heard about us on the s

This episode of ADU Adventures: Building in Your Backyard was sponsored by Acton ADU—California's experts in high-quality, long-lasting accessory dwelling units (ADUs). With 35+ years of experience, they handle everything from design to permits to construction, making the whole process seamless for homeowners.

Thinking about building an ADU? Visit ActonADU.com or call (408) 539-1908 to get started.

Thanks for listening—see you next time!

Acton ADU – The Home of the Build Ready ADU, Serving California Homeowners for More Than 35 Years

With more than 35 years of design-build experience, Acton ADU specializes exclusively in Accessory Dwelling Units (ADUs). Based in Campbell, California, we serve homeowners across more than 80 jurisdictions throughout in the San Francisco Bay Area, the East Bay, and the San Gabriel Valley.

We design and build high-quality, traditionally site-built backyard homes, delivering turnkey ADU solutions that save time and money without sacrificing quality. As the home of the Build Ready ADU, we offer curated, pre-designed plans built around multigenerational living and long-term property value, with pre-approved options in select cities for faster timelines.

Why Homeowners Choose Acton ADU:

• More than 35 years of design-build expertise
• Build Ready ADUs: pre-designed backyard homes for faster timelines and controlled costs
• Signature Series, Investor Series, and Aging-in-Place Series plans
• Traditionally site-built to California residential standards, not prefab
• Expert zoning and permitting guidance in every community we serve
• 5-star reviews from California homeowners
• Financing assistance to help you plan your investment

Whether you are building a mother-in-law suite, granny flat, or casita, Acton ADU is your trusted partner in creating a backyard home your family will rel...