Home equity loan
A lump-sum second mortgage that may use a fixed or adjustable rate. Compare its payment with your existing mortgage and verify all fees.
Ask: Do I have enough verified equity, and is the payment predictable?
Property-specific ADU planning
California ADU financing planner
Understand the payment before choosing a financing path
Compare a real amortized payment, total interest, rate sensitivity, equity and debt ratios. Every market benchmark is dated and sourced; every property or income figure remains yours to verify.
Transparent planning calculator
Test a complete financing scenario
Start with an editable project example, then replace every assumption with your own lender and household information. Results update immediately and never represent credit approval.
Loan assumptions
The $300,000 starting value is an editable example, not an average ADU price.
20%
$60,000 cash; $240,000 financed.
7.26%
Enter the actual APR from a Loan Estimate when available.
Equity and debt snapshot
Optional inputs calculate combined LTV and post-project DTI. They do not determine eligibility.
Use a current appraisal or your own planning estimate.
Include recurring debt payments you want in this planning ratio.
Optional rent and ROI assumptions
ADU.zone does not supply a rent forecast or property-value claim here. Enter independently researched values only.
Choose the product after the project
Four common paths to compare
The lowest advertised rate may not produce the lowest total cost. Compare how funds are released, whether the rate can change, which property secures the loan, and what happens to your existing mortgage.
HELOC
A revolving line secured by home equity. HELOC rates are usually variable, so both the payment and available credit can change.
Ask: What index, lender margin, draw period and repayment rules apply?
Construction or renovation loan
A project-specific product that may release funds through construction draws and require plans, budgets, inspections and a completion schedule.
Ask: Which project documents must be complete before underwriting?
Cash-out refinance
A new mortgage can replace the existing one and release equity. Compare the cost of repricing the entire mortgage, not only the ADU funds.
Ask: Does replacing my current mortgage improve or worsen the full cost?
Verified starting points
California programs and consumer guidance
There is no single statewide ADU loan or California-wide ADU interest rate. Program availability can be local, income-limited, property-specific or temporarily closed, so verify the current terms with the named agency.
California HCD funding directory
State-maintained starting point for ADU assistance and selected local programs. Availability and eligibility vary by program and jurisdiction.
Open official sourceCalHFA ADU Grant status
CalHFA says the latest ADU Grant funding round was fully allocated on December 28, 2023. Treat anyone offering access to that closed round with caution.
Open official sourceCFPB home-equity guidance
Federal consumer guidance explains the difference between a home equity loan and a HELOC, including variable-rate and repayment risk.
Open official sourceNext useful step
Refine the project scope before lender underwriting
A lender needs dependable numbers. Start with the property, model, finish level and site constraints so your financing conversation is based on a preliminary project range rather than a guess.