ADU Financing in Sacramento: Loans & Rental Income Guide
Accessory dwelling units, ADUs, granny flats, casitas, whatever your neighborhood calls them, are one of the more underused tools in the Sacramento housing market. California has spent the last several years passing laws to make them easier to build. Most buyers still don't know how to actually finance one, or how it can help them qualify for a bigger loan.
What counts as an ADU
An ADU is a secondary, independent living unit on the same lot as a primary home. That can be a detached backyard unit, a converted garage, or an attached unit with its own entrance. To count toward your loan the way described below, it generally needs to be a legal, permitted unit, not something built without permits.
Two different situations, two different financing paths
You're buying a home that already has an ADU. If the ADU is legal and has an established rental history, or the appraiser can support market rent for it, that rental income can potentially be used to help you qualify for the loan. This isn't automatic, it depends on the loan program and the appraisal, but it's a real option worth raising with your lender before you rule out a property because the payment looks tight on paper.
You want to build an ADU on a home you're buying or already own. This usually means either a renovation-style loan that lets you roll construction costs into your mortgage, a HELOC, or a cash-out refinance to fund the build. Each comes with different qualifying rules and different costs, and the right one depends on how much equity you have and what the ADU will realistically cost to build.
Why this matters for house hacking and investing
An ADU can work like a smaller-scale version of house hacking. You live in the main home, rent out the ADU, and use that income to offset your payment. For investors, a legal ADU can add rental income to a property without buying a full duplex or triplex.
Rules on how much of that rental income a lender can count vary by loan program and change over time. Don't assume a number, ask what applies to your specific loan and property before you build a budget around it.
What to check before you count on ADU income
Is the ADU permitted and legal, or does it need to be brought up to code first
Does it have its own utilities, entrance, and kitchen (requirements vary by jurisdiction)
Will the appraiser support a market rent estimate for it
Does your specific loan program allow that income to be counted, and how much
FAQ
Can I use future ADU rental income if it's not built yet? Sometimes, depending on the loan program and whether the appraisal can support projected rent. This is very case-by-case, talk to your lender before assuming either way.
Does building an ADU increase my home's value? Generally it can, since it adds usable living space and potential rental income, but the actual value impact depends on the local market and how the ADU is finished. Get an appraiser's opinion for your specific property rather than assuming a fixed return.
Is a garage conversion cheaper than a detached ADU? Usually yes, since you're not building a new foundation and structure from scratch, but costs vary a lot by scope and local permitting requirements.
Chris Kennedy, NMLS #971546, is the founder of Reliant Lending in Sacramento, helping buyers and investors across Sacramento, Placer, and El Dorado County figure out financing for ADUs, multi-unit properties, and rental income strategies.