Why Do People Build ADUs?

Before you think about floor plans or budgets, get clear on why you're building. Your reason should drive every decision that follows — size, layout, finishes, even which type of ADU makes sense.

Here are the reasons we see most:

Rental income. The most common driver. In much of California, a well-designed ADU rents for $1,800–$3,500+ per month depending on size and location. Rental ADUs favor efficient layouts, durable finishes, and privacy from the main house.

Housing parents. An ADU keeps aging parents close but independent — no stairs, wider doorways, a walk-in shower. Families often choose single-story layouts and put more budget into accessibility than into rental-style finishes.

Adult children. With rents where they are, many families build so a grown child can live affordably while saving. These units tend to be flexible: good for the kid now, good for a tenant later.

Aging in place. Some homeowners build the ADU for themselves — a single-story, low-maintenance home in the backyard — and rent out the main house. The bigger house generates the bigger rent.

Home office or flex space. A backyard studio for work, guests, or hobbies. Fair warning: if you want the option to rent it later, build it as a full ADU from day one. Adding a kitchen afterward is expensive.

Property value and future housing. Even if you have no immediate use, a permitted ADU typically adds significant appraised value and gives the next owner options. Some homeowners build now because construction costs rarely go down.

You don't have to pick just one reason. But when two goals conflict — say, maximum rent vs. the perfect setup for mom — knowing your primary reason tells you which way to lean.