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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

Finance · 8 min read · January 30, 2025 · 300 words

Financing an ADU without overpaying for the privilege

HELOC, cash-out refi, renovation loan, or cash: a side-by-side on the four real paths LA homeowners use — and the rate math that decides between them.

Key takeaways

  • Cash — lowest cost, gives up liquidity.
  • HELOC — fast, flexible, variable rate, refinance later.
  • Cash-out refi — only attractive when current rates are favorable.

There is no single right way to finance an ADU. There are four real paths, and the right one for you depends on three numbers: your current mortgage rate, your available equity, and your tolerance for variable-rate debt.

1. Cash

If you have it sitting in a HYSA earning 4%, paying cash for an ADU that yields 9–11% gross rental return is a clean trade. The downside is opportunity cost — you give up that liquidity and can't easily put it back if you need it.

2. HELOC (Home Equity Line of Credit)

Revolving credit secured by your home equity, typically interest-only during the draw period. Variable rate (currently around prime + 0–1.5%). Best when you're confident you'll refinance the construction debt into a permanent mortgage within 24 months.

3. Cash-out refinance

Refinance your primary mortgage for more than the balance and take the difference as cash. Best when current rates are at or below your existing mortgage rate. Worst when current rates are 2+ percentage points above — you'd be repricing your entire mortgage to fund $250K of new debt.

4. Renovation construction loan

Construction-to-permanent loan products (Fannie Mae HomeStyle, Freddie Mac CHOICERenovation) underwrite based on the post-build appraised value of the property. Best when you don't have enough current equity to cover the build with a HELOC.

Side-by-side, simplified

  • Cash — lowest cost, gives up liquidity.
  • HELOC — fast, flexible, variable rate, refinance later.
  • Cash-out refi — only attractive when current rates are favorable.
  • Renovation loan — best for low-equity homeowners or first-time builders.

FAQ · Finance

Common questions on finance

The questions readers send us most after this guide.

  1. What kind of return on investment can I expect?
    Across 120+ completed LA projects, our owners see 10–16% annual return on construction cost in long-term rental. The math: a $280K detached ADU renting at $2,800/month grosses $33,600/year — roughly a 12% gross yield before expenses. Property value uplift is typically 1.4–1.7× the build cost on appraisal.
  2. Are there grants or rebates available?
    The CalHFA ADU Grant Program ($40K toward soft costs) was paused in 2023 but a successor is in late-stage legislative drafting. LADWP offers rebates for high-efficiency HVAC and induction cooktops. We track every active program and apply on your behalf.
  3. What does an ADU cost in LA?
    Pricing depends on size, finish level, and site conditions. For 2026, our detached ADUs start around $250K for a 480 sq ft studio and run up to about $450K for a 1,200 sq ft custom build. Garage conversions begin around $145K. JADUs typically run $95K–$140K.
  4. What's included in your turnkey number?
    Architectural and structural design, Title 24 energy compliance, full permit fees and plan check, soils report when required, foundation, framing, MEP rough-in, insulation, drywall, doors, windows, kitchen, bathroom, flooring, paint, fixtures, and final cleaning. Excluded: landscaping beyond grading, solar (offered separately), and LADWP service upgrades when the existing panel can't carry the load.
  5. Will building an ADU raise my property taxes?
    Only the ADU portion is reassessed at its construction cost — the existing main house keeps its Prop 13 basis. On a typical $280K ADU, expect a property tax increase of roughly $2,800/year at LA's 1% rate plus local assessments.

Sources & further reading

  • California Government Code §65852.2 — statewide ADU framework (ministerial review, 60-day clock).
  • LADBS — Accessory Dwelling Unit information bulletins and current permit fee schedule.
  • HCD — California Department of Housing & Community Development, ADU handbook (2024 update).
  • Internal data: 120++ ADU projects delivered across Los Angeles County, 2018–2025.

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