Sacramento ADU Financing: HELOC, Cash-Out Refi, and Construction Loans Explained
Accessory dwelling units are everywhere in Sacramento right now. Garage conversions in East Sacramento. Backyard cottages in Carmichael. Attached suites in Elk Grove new builds. California law has made them easier to build, and Sacramento homeowners are adding them to generate rental income, house family, and build equity.
The question most people get wrong is how to pay for one. Here are the real options, what they actually cost to access, and which financing path fits which situation.
How Much Does an ADU Cost in Sacramento?
A Sacramento ADU typically runs $150,000 to $320,000 all-in, depending on the type.
ADU Type
Typical Sacramento Cost Range
Notes
Garage conversion
$80,000 - $150,000
Lower cost; existing structure
Attached ADU addition
$120,000 - $200,000
Shares a wall with main home
Detached new build (small)
$180,000 - $280,000
Full construction on lot
Detached new build (large)
$250,000 - $350,000+
Higher-end finishes, size
Very few homeowners pay cash for these projects. Most finance them through equity-based products or roll them into a purchase.
ADU construction costs in Sacramento shift with labor and material markets. These ranges reflect 2025-2026 conditions and should be verified locally before publishing.
Option 1: Cash-Out Refinance
You refinance your existing mortgage for more than you owe and take the difference in cash to fund the build.
Best for:
Homeowners who currently have a rate at or above today's market, or who have enough equity to pull significant cash without dramatically increasing their payment.
The catch:
If you locked a 3% rate in 2021, refinancing today means trading that rate for a current market rate on your entire loan balance. Run the math carefully. The monthly payment increase on your primary mortgage may offset ADU rental income faster than you expect.
Option 2: HELOC (Home Equity Line of Credit)
A HELOC gives you a revolving line of credit against your home equity. You draw funds as you need them during the build, pay interest only on what you've drawn, and then repay over time.
Best for:
Homeowners with a low first mortgage rate they don't want to disturb. The HELOC sits as a second lien; your first mortgage stays as-is.
The catch:
HELOCs are typically variable rate. When rates are high, so is your HELOC payment. Also, HELOC sizing depends on your available equity. Lenders typically lend to a combined loan-to-value of 80-85% of your home's current value.
Option 3: Construction Loan
A standalone construction loan funds the build in stages (draws) as work is completed, then converts to a permanent loan or gets paid off at completion.
Best for:
Homeowners who don't have enough equity for a HELOC, or who want a loan structure specifically designed for the construction draw process.
The catch:
Construction loans carry higher rates than traditional mortgages and have more complex underwriting. You typically need a licensed contractor with plans, permits, and a detailed budget in place before the loan funds.
Option 4: Buy a Home with an ADU Already Built
You find a Sacramento home that already has a permitted ADU and finance the whole thing with one mortgage. The ADU rental income may help you qualify.
How qualifying income works:
If you buy a property with an existing, permitted ADU, lenders can count 75% of the market rent from the ADU unit toward your qualifying income. This can meaningfully expand what you qualify for.
Fannie Mae also has specific ADU guidelines that allow the ADU rental income to be counted even without a lease in place, as long as an appraisal supports the market rent.
Best for:
First-time buyers who want to get into a property and reduce their monthly cost, or investors who want rental income from day one without the construction headache.
Option 5: Renovation Loan (Buy + Build in One)
If you're buying a home and want to add an ADU, a renovation loan like the FHA 203(k) Standard or Fannie Mae HomeStyle lets you finance the purchase and construction together in one loan.
Best for:
Buyers purchasing a property that doesn't already have an ADU and want to build one as part of the purchase. One loan, one close, one monthly payment.
The catch:
Renovation loans have a longer and more complex approval process. The contractor must be approved. All work must be completed within the loan's build window. Not every property or project qualifies.
What About the CalHFA ADU Grant?
IMPORTANT: Publishing The CalHFA ADU Grant Program (which previously offered up to $40,000 for pre-development costs) was reported as fully allocated as of late 2023 with no confirmed relaunch date as of mid-2026. Sources on current availability conflict. Verify status directly at calhfa.ca.gov/adu before referencing this program as available to clients. If funding has been restored, note the income limits (80% AMI for Sacramento County) and that the grant covers pre-development soft costs, not hard construction costs.
Using ADU Rental Income to Qualify When You're Building, Not Buying
If you already own your home and you're building an ADU, you generally cannot count projected future rent from the ADU toward your qualifying income until the ADU is complete and a lease is in place. This is different from buying a property with an existing ADU.
The path around this: complete the build, get a signed lease, then refinance if needed. Or structure the financing (HELOC, construction loan) based on your existing income without counting the ADU.
How the ADU Affects Your Property Value
A permitted, finished ADU adds appraised value to your Sacramento property. The amount varies by size, quality, and neighborhood. In Sacramento markets where rental demand is strong, a well-built ADU can add $100,000 to $200,000 to appraised value in some cases.
Unpermitted ADUs are a different story. An unpermitted ADU can create complications for financing (lenders may not count its square footage or income), title issues, and insurance problems. If you're buying a property with an unpermitted ADU, talk to both your loan officer and your Realtor about the implications before making an offer.
Frequently Asked Questions
Q: Can I build an ADU on a rental property I own?
A: Yes, but financing options may be more limited. Cash-out refi and HELOC products are available for non-owner-occupied properties, though the equity requirements and rates are typically less favorable than on a primary residence.
Q: Will my property taxes go up if I build an ADU?
A: Yes, in most cases. California property taxes are reassessed when you add new construction. The ADU square footage will be reassessed at current market value. This is an important number to factor into your ROI calculation before starting the project.
Q: Can a veteran use a VA loan to buy a property with an ADU?
A: Yes. VA loans allow purchase of multi-unit properties up to four units, and a single-family home with a permitted ADU is treated as a single-family property. The VA appraiser will value the ADU as part of the property.
Q: How do I know if my Sacramento lot allows an ADU?
A: California state law allows ADUs on most single-family and multi-family lots, but local setback, size, height, and utility requirements vary by city and county. The City of Sacramento, City of Folsom, City of Roseville, and Sacramento County each have their own ADU ordinances. Check with the planning department before you commit to a project.
Ready to talk? Call (916) 794-0777 or visit thechriskennedyteam.com | NMLS #971546 | Serving Sacramento, Placer, El Dorado, and Yolo Counties. This article is for educational purposes only and is not a commitment to lend. Rates and program guidelines are subject to change. Contact a licensed loan officer for current terms and a personalized quote.