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Vol. I ·California ADU Desk ·Licensed · Bonded · Insured ·CSLB #1098432 ·BBB A+ Accredited ·120+ ADUs Delivered ·Starting $250K ·10–16% ROI ·Los Angeles ·Bay Area ·Vol. I ·California ADU Desk ·Licensed · Bonded · Insured ·CSLB #1098432 ·BBB A+ Accredited ·120+ ADUs Delivered ·Starting $250K ·10–16% ROI ·Los Angeles ·Bay Area ·
GoldenStateADU
The Ledger · Financing

What will it cost monthly?

LA ADUs typically run $250K–$450K all-in. A first approximation below — we'll refine with your lender.

Draw schedule funds the build, converts to a 30-yr mortgage at C-of-O.

280,000How much you'll borrow toward the build. LA ADU loans typically run $150K–$400K.
9.25Annual interest rate. Current CA averages — HELOC 8.0–9.5%, construction 8.5–10.5%, refi 6.75–7.75%.
30Years to repay. HELOCs: 10-yr draw / 20-yr repay; construction-to-perm: 30 yrs.
Monthly payment
$2,303

Principal + interest, fully amortized. Excludes taxes, insurance, HOA.

Total paid over term
$829,257

Monthly payment × number of payments over the full term.

Total interest
$549,257

Total paid minus the original loan amount.

Estimates only. Excludes taxes, insurance, closing costs. Confirm rates with your lender. Golden State ADU does not provide financial advice.

The Ledger · Financing

Payment breakdown

Where each dollar of your monthly payment goes — and how it compounds over the term.

Principal
$280,000

The original loan amount you'll repay.

Interest
$549,257

What the lender earns over the life of the loan.

Total payments
360

360 monthly installments over 30 years.

Principal vs. interest34% · 66%
Principal Interest

FAQ

Frequently asked questions

What homeowners ask before choosing a loan product to fund an LA ADU.

  1. Which loan product is best for an LA ADU?
    HELOCs offer the lowest barrier when you have 30%+ equity and want flexible draws. Construction loans (one-time-close) are best for ground-up detached ADUs above $200K because they fund draws against milestones. Cash-out refis make sense when current mortgage rates are below market and you can absorb a higher payment on the full balance.
  2. How accurate are the rates in this calculator?
    Rates are LA-calibrated 2025 averages from our credit-union and private-lender partners. Your actual rate depends on credit score, LTV, occupancy, and loan size. Use this tool to compare scenarios — bring the result to a lender for a hardened quote.
  3. Can I include the ADU rental income in my qualifying ratio?
    Some lenders count 75% of projected market rent against your DTI once a signed appraisal supports it. Construction lenders typically don't — they qualify against current income only. We can introduce you to lenders who underwrite the rent-add scenario.
  4. Are there any fees this calculator doesn't show?
    Origination, title, appraisal, and recording fees are not included — plan on 1–3% of loan amount in closing costs. Construction loans add a draw-inspection fee per disbursement (typically $150–$300 each).
  5. Should I lock the rate before construction starts?
    If you're using a one-time-close construction loan, the rate locks at closing for the full term. Two-step construction loans float during build and re-lock at conversion to permanent financing — riskier in a rising-rate environment.
  6. HELOC vs renovation loan vs cash-out — which fits an ADU best?
    Use a HELOC when you have flexible draw needs and want to ladder rates. Pick a Fannie Mae HomeStyle or Freddie Mac CHOICERenovation loan when you need to roll the build cost into a single first mortgage. Cash-out refi makes sense only when current rates beat your existing mortgage by enough to absorb the higher monthly payment.