ADU Rental Income & ROI: Do Backyard Units Actually Pay Off?

For many homeowners the ADU math is simple: does the rent cover the loan? Often it does — but the answer depends on your build cost, local rents and how you finance it.

Estimating rental income

A detached ADU typically rents for 60–80% of a comparable standalone home in the same area because it's smaller and shares a lot. Check local listings for studios and one-bedrooms, then discount slightly. A unit renting at $1,800/month produces $21,600 a year before expenses.

The payback math

Divide your all-in build cost by annual net rent for a rough payback period. A $180,000 ADU netting $18,000/year pays back in about 10 years — and then becomes pure cash flow, on top of the resale value it added to your property.

What makes ROI strong

• A cheaper build path (garage conversion or prefab) lowers the denominator.
• High local rents (coastal metros) raise the numerator.
• No owner-occupancy requirement, so you can rent both units.
• Financing at a rate below your expected rental yield.
• Short-term or mid-term rental in a tourist or travel-nurse market.

What weakens it

Expensive custom detached builds in low-rent areas, high financing rates, and strict owner-occupancy or short-term-rental bans. Run your specific numbers before committing.