See what an ADU could add to your California property.
California's ADU laws changed the math: no owner-occupancy requirement, fast ministerial approval, and units up to 1,200 sq ft. See your size and cost range, then request estimates from contractors who hold an active CSLB license.
- Every ADU contractor introduced must hold an active CSLB license
- Planning size & cost range in three short steps, before you talk to anyone
- Your contract and payments are directly with your licensed contractor
- No obligation: requesting estimates commits you to nothing
MaverickXL is a contractor referral service, not a contractor. It does not bid, perform or manage construction. Own a property with 2+ existing units? Try the SB 1211 multifamily ADU calculator instead. Cost figures are published planning ranges, not quotes. See sources.
Get your ADU size & cost range
What kind of ADU are you exploring?
From size and cost range to a signed contract with a licensed ADU builder.
MaverickXL introduces you. Your contractor prepares the estimate and the contract, and you decide.
Tell us about your property
Choose your ADU type, target size and region. You see a planning range immediately.
We introduce licensed ADU contractors
Each contractor we introduce must hold an active CSLB license for ADU/new-construction work.
Compare written estimates
Every contractor prepares their own scope, design and price. Compare them side by side.
Sign directly with your choice
Your contract is with your contractor, and so are your payments. MaverickXL is not a party to it.
Know the range before you talk to a builder.
Pick your ADU type and size. Ranges are cross-checked across Los Angeles ADU-builder guides and one prefab manufacturer's published statewide pricing.
New detached, stick-built construction: foundation, framing, roof, utilities and finishes. Cost per square foot falls as the unit gets larger.
| ADU type | Size | Typical total (national/CA guides) | $ / sq ft |
|---|---|---|---|
| New detached, stick-built | 400–1,200 sq ft | $150,000–$400,000+ | $250–$500 |
| New detached, prefab (one manufacturer) | 385–1,195 sq ft | $298,800–$498,800 all-in | $330–$610 (higher on small units) |
| Garage conversion | ~200–400 sq ft | $70,000–$200,000+ | $125–$400 |
| JADU (inside existing home) | up to 500 sq ft (state cap) | $40,000–$125,000 | — |
By size tier (new detached, stick-built): studio/1BR (400–600 sq ft) typically $150,000–$300,000; 2BR (700–1,000 sq ft) typically $250,000–$350,000; larger (1,000–1,200+ sq ft) typically $300,000–$400,000+. Smaller units cost more per square foot because permitting, utility hookups and a kitchen/bath cost about the same regardless of size — those fixed costs spread over fewer square feet. Sources and dates are listed below; JADU figures come from fewer, less-verified sources than the other three rows.
Design, structural engineering and Title 24 energy compliance, per a Los Angeles ADU-builder guide.
ADUs under 750 sq ft are exempt from local impact fees by state law (Gov. Code §66323); plan-check fees still apply.
Converting existing space usually needs no new utility connection; a new detached unit may, depending on your water/sewer provider.
Grading, utility trenching and site access can add 20–30% to a garage conversion that needs new underground lines.
Line items and the utility-connection rule are general guidance, not a bid for your lot. See "Sources & method" below for every figure's source and date.
Detached unit, garage conversion, or a JADU inside your home.
Each has a different cost, timeline and approval path.
New detached ADU
A freestanding unit in the backyard, up to 1,200 sq ft under most local ordinances, with an 800 sq ft / 4-ft-setback version guaranteed by state law regardless of local zoning.
Block Renovation-style national range; GreatBuildz LA, Villa Homes, Abodu, 2026Garage conversion
Convert an existing garage. No replacement parking is required by state law (Gov. Code §66314(d)(11)) when a garage is converted or demolished for an ADU.
Angi/HomeGuide, CaliFirst Remodel, 2026JADU
A unit of up to 500 sq ft built inside your existing home's walls, sharing some or all systems. Generally the fastest and least expensive path.
Multiple contractor guides, 2026 (fewer independent sources)What the state guarantees you, and what it doesn’t.
General information, not legal advice. California recodified ADU law in 2024 (SB 477); the citations below use the current Government Code sections.
Local ordinances may allow a detached ADU up to 1,200 sq ft (or an attached ADU up to 50% of the primary home). Separately, state law guarantees at least an 800 sq ft detached ADU with 4-ft side/rear setbacks regardless of stricter local rules.
Gov. Code §66314, §66323You do not have to live in the main house, or the ADU, to build or keep one. This applies statewide as of 2026.
Gov. Code §66315Cities must approve or deny a complete ADU application within 60 days, with no discretionary hearing. Miss the deadline and it is deemed approved.
Gov. Code §66317, §66321When a garage or carport is demolished or converted for an ADU, the city cannot require you to replace those parking spaces.
Gov. Code §66314(d)(11)Local agencies, special districts and water corporations cannot charge impact fees on an ADU under 750 sq ft. Larger ADUs are charged proportionally to the primary home's size.
Gov. Code §66323A lot with an existing multifamily building can add up to 8 detached ADUs, capped at the number of existing units on the lot. Own a 2+ unit property? Use the SB 1211 calculator for your specific numbers.
Gov. Code §66323(a)(4) (SB 1211)An ADU can be rented separately from the main home for terms of 30 days or more. State law requires that 30-day minimum, and bars short-term/vacation rental of a new ADU for the first year after it's approved for occupancy; many cities restrict ADU short-term rentals further.
Gov. Code §66323(e); Gov. Code §66311.7 (AB 2533)ADU construction almost always needs a building permit, and California's minor-work exemption for unlicensed work only applies when no permit is required. In practice, a CSLB-licensed contractor (or a true owner-builder permit) is required to build an ADU.
Bus. & Prof. Code §7028, §7048How California homeowners typically finance an ADU.
These are common financing paths, not an offer of credit from MaverickXL. Rates and terms come from your lender.
Common financing paths
- Home equity line of credit (HELOC) — commonly cited variable rates around 7.75%–9.50% in 2026
- Cash-out refinance — rates commonly cited from about 6.5%; weigh against giving up a lower existing mortgage rate
- Construction loan, converting to a permanent mortgage — commonly cited around 7.0%–9.0%
- Refinance after completion using the ADU's rental income to qualify (a DSCR-style loan)
What ADU rent typically runs
Vendor-reported figures from California ADU builders, not an independent rent survey. Actual rent depends on your city, unit size and finishes.
A note on the CalHFA ADU Grant Program: it provided up to $40,000 toward pre-development costs, but the program has been fully allocated and closed since December 2023 with no announced reopening. CalHFA's own site warns that anyone offering to help you "secure" this grant today is likely running a scam — we do not offer it and no one legitimately can, right now.
Design, permit, then build.
Published timelines vary by city and scope. Your contractor sets the schedule in your written contract.
- Plans, structural & Title 242–5 mo
- Pre-approved standard plansas little as 2 wks
- Sacramento / San Diego (typical)4–8 wks
- Los Angeles (typical)8–16 wks
- State ministerial cap60 days
- Garage conversionWeeks to a few months
- New detached, stick-built (ground-up)4–8 mo
- Prefab, on-site installAs fast as 1 day (unit set)
Sources: GreatBuildz and Vision ADU (Los Angeles, 2026): total ground-up timeline 9–16 months for most LA projects, construction 4–8 months of that; NP Line Design and other 2026 CA ADU guides: design 2–5 months, permitting 3–8 months, statewide total 10–18+ months for new construction. Gov. Code §66317/§66321 (60-day ministerial cap) and SB 543 (15-business-day completeness check, effective January 1, 2026) bound the PERMITTING phase only, not the total project. Get your contractor's actual schedule in writing.
Before you request estimates.
How much does it cost to build an ADU in California?
How big can an ADU be in California?
Do I have to live on the property to build an ADU?
How long does ADU permitting take in California?
Can I rent out my ADU, and can I list it on Airbnb?
Is there still a $40,000 state grant for building an ADU?
Do I need a licensed contractor to build an ADU?
Is MaverickXL the company that builds the ADU?
What if I own a property with 2 or more existing units?
What happens after I submit the form?
Sources & method
How the planning range is built. New-detached and garage-conversion ranges are cross-checked across a Los Angeles ADU-builder guide, a statewide ADU-builder site, and one prefab manufacturer's published all-in pricing; the displayed range is the overlap most sources support. JADU figures rest on fewer, less-verified sources and are flagged as such. Contractor and manufacturer sites are marketing content, not independent research. None of these figures is a quote.
- GreatBuildz, Los Angeles ADU cost guide (updated July 28, 2026): totals, $/sq ft, line items, timeline.
- Villa Homes, Los Angeles / California ADU pricing (2026): $/sq ft range.
- Abodu, California ADU cost guide (2026): prefab all-in pricing by model size.
- Angi, Garage-to-ADU conversion cost (2026).
- California Government Code §§66310–66342 (ADU/JADU law, recodified by SB 477, effective March 25, 2024), including §66314, §66315, §66317, §66321, §66323, §66311.7, at leginfo.legislature.ca.gov.
- CalHFA, ADU Grant Program status: confirms the program has been fully allocated since December 2023.
- Contractors State License Board, cslb.ca.gov.
Photographs are free-to-use stock images (Pexels License) shown for illustration only. They are not MaverickXL projects, and the people and properties pictured have no connection to MaverickXL or its contractors.
Get your ADU size, cost range and licensed-contractor introductions.
Choose your ADU type, see a planning range, and request written estimates. You commit to nothing until you sign a contract with the contractor you choose.
