ADU Financing in California: Loans, HELOCs and the CalHFA Grant (2026)

Most ADUs in Southern California are financed, at least in part. The right loan depends on how much equity you have, your current mortgage rate, and how much you need to borrow. Here's a plain-English comparison. We're a directory, not a lender, and nothing here is a loan offer or financial advice.

First: the CalHFA ADU Grant is closed

The California Housing Finance Agency's ADU Grant Program offered up to $40,000 to reimburse pre-development and non-recurring closing costs. That covered things like plans, permits, soil tests, impact fees, surveys and energy reports. It never paid for construction.

Current status: CalHFA's ADU page reports that the latest round of funding was fully allocated as of December 28, 2023. HCD's March 2026 ADU Handbook also describes the funds as exhausted. As of our last check (November 2026), CalHFA had not announced a new round.

CalHFA warns that anyone offering to help you get an ADU grant right now is likely running a scam. Report it to CalHFA. Watch CalHFA's own page for any future round.

Option 1: Home equity line of credit (HELOC)

• How it works: a revolving credit line secured by your home, usually with a variable rate. You draw what you need during construction.
• Good for: owners with substantial equity who want to keep a low-rate first mortgage.
• Watch out for: variable rates, and borrowing limits based on your *current* value, not the value after the ADU. Some lenders also freeze or reduce lines.

Option 2: Cash-out refinance

• How it works: you replace your mortgage with a larger one and take the difference in cash.
• Good for: owners whose current rate is near or above today's market rates, or who need a large fixed-rate sum.
• Watch out for: giving up a low existing rate, closing costs, and limits based on current value.

Option 3: Construction loan (or construction-to-permanent)

• How it works: the lender funds the build in draws, released after inspections. Many convert to a permanent mortgage after completion. Some loans are based on the projected value after the ADU is complete.
• Good for: larger detached projects, and owners with less current equity.
• Watch out for: more paperwork. Lenders review your contractor, plans and budget, and draw inspections can slow payments to your builder.

Option 4: Renovation loans based on after-completion value

RenoFi-type renovation loans, plus agency renovation products such as Fannie Mae's HomeStyle Renovation, let you borrow against the home's after-renovation value. That can significantly raise how much you can borrow. Fannie Mae and Freddie Mac both publish ADU guidance, and HCD's Handbook notes that some ADU rental income can count toward qualifying income for certain loans. Availability and terms change, so compare current offers from several lenders.

Option 5: Personal loans, cash and contractor financing

These can work for small JADUs or as gap funding, but rates are typically higher. If a contractor offers financing, read the terms carefully, and never sign a loan you haven't fully reviewed.

Local programs in Southern California

• San Diego Housing Commission ADU Finance Program: a repayable construction loan for eligible City of San Diego homeowners, with income limits, technical assistance and an affordability requirement, according to SDHC. Check SDHC for current terms.
• Other cities and counties occasionally run fee waivers, forgivable loans or pilot programs, often tied to renting at affordable rates. Many have ended, or have waitlists. Ask your city's housing department.

Fee savings that need no application

ADUs of 750 sq ft or less pay no impact fees under Government Code section 66311.5, and many conversions avoid utility capacity charges. Designing at 749 sq ft is one of the simplest ways to save. See our ADU laws page.

Comparing your options

When you talk to lenders, ask each one:

1. What's the maximum I can borrow: based on current value, or after-completion value?
2. Is the rate fixed or variable? What are the total closing costs?
3. How are construction draws handled, and how fast are they released?
4. Do you count projected ADU rental income?
5. What do you require from my contractor (license, insurance, contract)?

Partner offers

We don't currently have lending partners. If we add any, we'll clearly disclose the relationship.

Next steps

• Estimate your budget with our ADU cost estimator.
• Read ADU rental income and property taxes.
• Find ADU builders near you.

Frequently asked questions

This page is general information, not legal, tax or financial advice. Costs vary by property and builder. Images are AI-generated illustrations. Last updated November 2026.