Accessory Dwelling Units — ADUs, also called granny flats or casitas — have become one of the most common projects we're asked about in Orange County, whether for aging parents, adult kids, a home office, or rental income. Here's how to think through the basics before you call a contractor.
Three Paths to an ADU
A detached ADU is a standalone structure on your lot with its own foundation and utility connections — the most flexible option, but generally the most involved build. An attached addition extends your existing home's footprint, sharing at least one wall. A garage conversion repurposes an existing structure, which is often the fastest and most budget-conscious path since the foundation and framing are already there.
Junior ADUs Are a Different Animal
A Junior ADU (JADU) is a smaller unit built within the existing walls of your home, typically sharing a bathroom or entry with the main house. It's a different scope and different rules than a full ADU, so it's worth clarifying which one actually fits your goals before you start designing.
What Actually Drives the Timeline
Design and engineering come first, followed by city plan-check and permitting, and then construction. Plan-check timelines vary significantly by city and current volume — this is usually the least predictable part of the process, and it's why we manage the permit submission and follow-up directly rather than leaving you to track it down.
Lot Constraints Matter More Than People Expect
Setbacks, easements, existing structures, and utility access can all shape what's realistically buildable on a given lot before design even starts. A site walk early in the process saves a lot of redesign later.
Rental Income and Occupancy Rules
Many homeowners build ADUs specifically to generate rental income or house family. Rules around rental use and owner-occupancy requirements can vary by city and do change over time, so we recommend confirming current requirements for your specific property rather than relying on general assumptions.
The projects that go smoothest are the ones where design, permitting, and construction are managed as one continuous process — not three separate vendors handing off to each other.
If you're weighing a detached ADU against a garage conversion or addition for your property, see how we approach ADU projects or request a free consultation to talk through your specific lot.