An ADU builder in Los Angeles is a licensed contractor who designs and constructs accessory dwelling units — detached backyard units, garage conversions, attached additions, and junior ADUs (JADUs). Because an ADU is a complete second dwelling, the builder coordinates foundation, framing, plumbing, electrical, and HVAC work and pulls it through Los Angeles's permit process and utility connections. Not every general contractor has built one, so the right builder is one with ADU-specific experience in California.
What ADU Builders Cost in Los Angeles [16][17][18][19][20][21]
Based on our Los Angeles cost data, expect the following ranges from local ADU builders. Quotes for the same scope typically vary 20-40% between contractors, so getting at least three bids is the single best way to control cost.
| New Detached ADU (all-in) | $220,000-$400,000 |
| Cost per Sq Ft | $300-$500 |
| Garage Conversion | $100,000-$200,000 |
| Prefab / Modular ADU (installed) | $120,000-$350,000 |
| City Permit & Plan Review | No flat ADU fee. The LADBS building permit fee is set by construction valuation under LAMC 91.107 Table 1-A: for a valuation between $100,000 and $500,000 the codified base is $395 plus $3.50 per $1,000 (about $1,445 on $300,000, or about $2,384 as a combined building-mechanical permit at 165% of that figure), plus plan check at 90% of the permit fee (91.107.3.1.1), a 2% plan-maintenance fee (91.107.4.3), a fire-hydrant fee of 0.22% of valuation on jobs of $50,000 or more (91.107.4.4), state seismic and green-code surcharges, and the City Planning General Plan Maintenance Surcharge, raised from 7% to 10% on June 9, 2026 (CF 09-0969-S4). Table 1-A amounts are indexed to CPI every July 1 (91.107.1.1), so run the LADBS Permit Fee Calculator for the current total. LAUSD developer fees of $5.38 per sq ft apply to an ADU larger than 500 sq ft from August 11, 2026 (about $4,300 on 800 sq ft) |
| Impact Fees | None for an ADU with 750 sq ft of interior livable space or less or a JADU of 500 sq ft or less; a larger ADU pays in proportion to the main house's floor area (Gov. Code 66311.5(c)(1), as renumbered by SB 543). In Los Angeles this covers the Dwelling Unit Construction Tax (LAMC 21.10.3) and Residential Development Fee (21.13.3); ADUs and JADUs are exempt from park fees (LAMC 12.33, Ordinance 186,481 Sec. 4-6) and the Affordable Housing Linkage Fee (19.18) at any size (ZA Memo 143 Sec. III.D). Sewer and water capacity charges are not impact fees: a conversion unit inside the house or garage pays no new connection or capacity charge, and any other ADU pays one proportional to its burden (66311.5(b), (d)-(e)); confirm the Sewerage Facilities Charge with the Bureau of Engineering |
For a full line-item breakdown, see our Los Angeles ADU cost guide. To confirm what you're allowed to build before you hire, review the Los Angeles ADU rules (max detached size: 1,200 sq ft under the city ordinance (12.22 A.33(d)(1)), subject to the lot's floor-area (RFA/FAR) and lot-coverage limits; the state-law option (Gov. Code 66323(a)(2)) is 800 sq ft, and no floor-area, lot-coverage, open-space, front-setback or lot-size rule may block an 800 sq ft unit with 4-ft side and rear setbacks (12.22 A.33(c)(1)(iii); Gov. Code 66321(b)(3)). Square footage is measured as Building Code gross floor area inside the exterior walls (ZA Memo 143 Q.3). Conversions of an existing garage or accessory building have no size cap and may add up to 150 sq ft for entry and exit (66323(a)(1)); owner-occupancy: Not required for an ADU (Gov. Code 66315 as amended by AB 976, permanent). A JADU requires owner-occupancy of the house or the JADU only when the JADU shares a bathroom with the house (Gov. Code 66333(b) as amended by AB 1154, effective January 1, 2026); every JADU still records a deed restriction against separate sale (66333(c); ZA Memo 143 Sec. II.B). ADUs may not be sold separately from the house except under the Gov. Code 66341 nonprofit exception (12.22 A.33(h)(3))).
Get Free ADU Quotes in Los Angeles
Tell us about your project and we'll pass it to ADU builders serving Los Angeles. Free, no obligation — you choose who to work with. We don't have builders in every area yet; if nobody covers yours, we'll email you to say so.
1. Tell us your project
Takes about a minute.
Takes about a minute.
2. We match local pros
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
3. You choose
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.
How to Vet an ADU Builder in Los Angeles
- License: Confirm a current contractor's license in California and that it's in good standing. Ask for the license number and verify it with the state board.
- ADU-specific experience: Ask how many ADUs they've completed in or near Los Angeles and request addresses or photos. ADU permitting and setbacks differ from a kitchen remodel.
- Portfolio & references: Get references from recent ADU clients and, if possible, visit a finished unit.
- Insurance: Verify general liability and workers' compensation coverage. Ask for a certificate of insurance.
- Written, detailed bid: Insist on an itemized, fixed-price or clearly-scoped bid — not a verbal estimate. It should state whether permits (No flat ADU fee. The LADBS building permit fee is set by construction valuation under LAMC 91.107 Table 1-A: for a valuation between $100,000 and $500,000 the codified base is $395 plus $3.50 per $1,000 (about $1,445 on $300,000, or about $2,384 as a combined building-mechanical permit at 165% of that figure), plus plan check at 90% of the permit fee (91.107.3.1.1), a 2% plan-maintenance fee (91.107.4.3), a fire-hydrant fee of 0.22% of valuation on jobs of $50,000 or more (91.107.4.4), state seismic and green-code surcharges, and the City Planning General Plan Maintenance Surcharge, raised from 7% to 10% on June 9, 2026 (CF 09-0969-S4). Table 1-A amounts are indexed to CPI every July 1 (91.107.1.1), so run the LADBS Permit Fee Calculator for the current total. LAUSD developer fees of $5.38 per sq ft apply to an ADU larger than 500 sq ft from August 11, 2026 (about $4,300 on 800 sq ft)), plan check (Electronic plan check through LADBS ePlanLA or in person at a Development Services Center; LADBS reviews building, residential and green code and zoning compliance in one ministerial review, and only conditions affected by the ADU that threaten health or safety must be corrected (Gov. Code 66322(b); ZA Memo 143 Q.25-Q.26). Fire sprinklers are not required unless the main house needs them (12.22 A.33(c)(10)); a new detached ADU must have solar panels under the state energy code (LADBS ADU page); the Fire Department requires a separate address for every unit including a JADU; a JADU needs an efficiency kitchen and, if it shares a bathroom, an interior door to the house), and impact fees (None for an ADU with 750 sq ft of interior livable space or less or a JADU of 500 sq ft or less; a larger ADU pays in proportion to the main house's floor area (Gov. Code 66311.5(c)(1), as renumbered by SB 543). In Los Angeles this covers the Dwelling Unit Construction Tax (LAMC 21.10.3) and Residential Development Fee (21.13.3); ADUs and JADUs are exempt from park fees (LAMC 12.33, Ordinance 186,481 Sec. 4-6) and the Affordable Housing Linkage Fee (19.18) at any size (ZA Memo 143 Sec. III.D). Sewer and water capacity charges are not impact fees: a conversion unit inside the house or garage pays no new connection or capacity charge, and any other ADU pays one proportional to its burden (66311.5(b), (d)-(e)); confirm the Sewerage Facilities Charge with the Bureau of Engineering) are included.
- Permit handling: Confirm they manage Los Angeles's permit process ("Ministerial building permit from the Department of Building and Safety (LADBS); no City Planning case, hearing or variance for a code-compliant unit (12.22 A.33(c)(2), Q.21). In order: 1) look up the lot on ZIMAS for zone, Hillside Area, VHFHSZ, HPOZ, Specific Plan and Coastal flags and print the SB 9/transit proximity sheet used for the parking and height waivers (ZA Memo 143 Q.34); 2) pick a state-law unit (Gov. Code 66323) or a city-ordinance unit (12.22 A.33) using ZA Memo 143 Tables 1-2, which decide size, height, setbacks and parking; 3) draw plans or license one of LADBS's pre-approved standard plans; 4) file plan check with LADBS through ePlanLA or at a Development Services Center, where LADBS checks building, residential and green code plus zoning; 5) clear Fire Department address assignment, Bureau of Engineering sewer and driveway items, LADWP service and LAUSD school fees; 6) permit issued, inspections, then a certificate of occupancy, which cannot issue before the main house has one (12.22 A.33(h)(5)). Unpermitted ADUs built before January 1, 2020 can be legalized under AB 2533 per LADBS bulletin P/BC 2026-161", typically The city must tell you within 15 business days whether the application is complete and must approve or deny it within 60 days of a complete application, or it is deemed approved (Gov. Code 66317(a) as amended by SB 543, in force January 1, 2026; LAMC 12.22 A.33(c)(2); ZA Memo 143 Q.24). If the ADU is filed with a new house, the ADU permit may wait for the house permit. LADBS publishes no average ADU plan-check turnaround; the Standard Plan Program is described only as shortening plan check) and who is responsible if revisions are required.
- Payment schedule: Avoid large upfront payments. A reasonable schedule ties payments to completed milestones.
Questions to Ask Before You Hire
- How many ADUs have you built in Los Angeles in the last two years?
- Is your bid fixed-price, and what would trigger a change order?
- Are permits, plan check, and utility connection fees included?
- What's a realistic timeline, including permit review (The city must tell you within 15 business days whether the application is complete and must approve or deny it within 60 days of a complete application, or it is deemed approved (Gov. Code 66317(a) as amended by SB 543, in force January 1, 2026; LAMC 12.22 A.33(c)(2); ZA Memo 143 Q.24). If the ADU is filed with a new house, the ADU permit may wait for the house permit. LADBS publishes no average ADU plan-check turnaround; the Standard Plan Program is described only as shortening plan check) and construction?
- Who is my point of contact and how are delays communicated?
- What warranty do you provide on workmanship?
- Can you share three recent California ADU client references?
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Are you an ADU builder? Get Los Angeles leads
Homeowners on this page submit real ADU project requests in Los Angeles. Each one goes to up to five local builders — that is what the homeowner agrees to — so claiming never takes it from anyone and there is no bidding. In practice far fewer ever make contact, which is why the number is five rather than three. A flat $50 only on the leads you accept: no subscription, no contract, and you deal with the homeowner directly.
Get Los Angeles ADU Leads →Frequently Asked Questions
How much do ADU builders charge in Los Angeles?
ADU builders in Los Angeles typically quote $220,000-$400,000 for a new detached unit, or about $300-$500 per square foot, including design, permitting, and construction. A garage conversion runs $100,000-$200,000 and a prefab/modular ADU averages $120,000-$350,000. Add city permit and plan-review fees (No flat ADU fee. The LADBS building permit fee is set by construction valuation under LAMC 91.107 Table 1-A: for a valuation between $100,000 and $500,000 the codified base is $395 plus $3.50 per $1,000 (about $1,445 on $300,000, or about $2,384 as a combined building-mechanical permit at 165% of that figure), plus plan check at 90% of the permit fee (91.107.3.1.1), a 2% plan-maintenance fee (91.107.4.3), a fire-hydrant fee of 0.22% of valuation on jobs of $50,000 or more (91.107.4.4), state seismic and green-code surcharges, and the City Planning General Plan Maintenance Surcharge, raised from 7% to 10% on June 9, 2026 (CF 09-0969-S4). Table 1-A amounts are indexed to CPI every July 1 (91.107.1.1), so run the LADBS Permit Fee Calculator for the current total. LAUSD developer fees of $5.38 per sq ft apply to an ADU larger than 500 sq ft from August 11, 2026 (about $4,300 on 800 sq ft)) plus impact fees of None for an ADU with 750 sq ft of interior livable space or less or a JADU of 500 sq ft or less; a larger ADU pays in proportion to the main house's floor area (Gov. Code 66311.5(c)(1), as renumbered by SB 543). In Los Angeles this covers the Dwelling Unit Construction Tax (LAMC 21.10.3) and Residential Development Fee (21.13.3); ADUs and JADUs are exempt from park fees (LAMC 12.33, Ordinance 186,481 Sec. 4-6) and the Affordable Housing Linkage Fee (19.18) at any size (ZA Memo 143 Sec. III.D). Sewer and water capacity charges are not impact fees: a conversion unit inside the house or garage pays no new connection or capacity charge, and any other ADU pays one proportional to its burden (66311.5(b), (d)-(e)); confirm the Sewerage Facilities Charge with the Bureau of Engineering. Quotes for the same scope commonly vary 20-40% between builders, so collect at least three bids.
How do I find a good ADU builder in Los Angeles?
Look for a licensed contractor with completed ADU projects in Los Angeles specifically — ADUs involve local zoning, setback rules, and utility connections that general remodelers may not have handled. Verify the license, ask for an ADU-specific portfolio and references, confirm they carry liability and workers' comp insurance, and get a written fixed-price or detailed bid. Submit a request below and we'll forward it to local ADU builders serving Los Angeles for free quotes.
Do ADU builders in Los Angeles handle permits?
Most full-service ADU builders manage the permit process for you. In Los Angeles the approval process is "Ministerial building permit from the Department of Building and Safety (LADBS); no City Planning case, hearing or variance for a code-compliant unit (12.22 A.33(c)(2), Q.21). In order: 1) look up the lot on ZIMAS for zone, Hillside Area, VHFHSZ, HPOZ, Specific Plan and Coastal flags and print the SB 9/transit proximity sheet used for the parking and height waivers (ZA Memo 143 Q.34); 2) pick a state-law unit (Gov. Code 66323) or a city-ordinance unit (12.22 A.33) using ZA Memo 143 Tables 1-2, which decide size, height, setbacks and parking; 3) draw plans or license one of LADBS's pre-approved standard plans; 4) file plan check with LADBS through ePlanLA or at a Development Services Center, where LADBS checks building, residential and green code plus zoning; 5) clear Fire Department address assignment, Bureau of Engineering sewer and driveway items, LADWP service and LAUSD school fees; 6) permit issued, inspections, then a certificate of occupancy, which cannot issue before the main house has one (12.22 A.33(h)(5)). Unpermitted ADUs built before January 1, 2020 can be legalized under AB 2533 per LADBS bulletin P/BC 2026-161" with a typical review timeline of The city must tell you within 15 business days whether the application is complete and must approve or deny it within 60 days of a complete application, or it is deemed approved (Gov. Code 66317(a) as amended by SB 543, in force January 1, 2026; LAMC 12.22 A.33(c)(2); ZA Memo 143 Q.24). If the ADU is filed with a new house, the ADU permit may wait for the house permit. LADBS publishes no average ADU plan-check turnaround; the Standard Plan Program is described only as shortening plan check. Confirm in writing whether permit fees, plan check (Electronic plan check through LADBS ePlanLA or in person at a Development Services Center; LADBS reviews building, residential and green code and zoning compliance in one ministerial review, and only conditions affected by the ADU that threaten health or safety must be corrected (Gov. Code 66322(b); ZA Memo 143 Q.25-Q.26). Fire sprinklers are not required unless the main house needs them (12.22 A.33(c)(10)); a new detached ADU must have solar panels under the state energy code (LADBS ADU page); the Fire Department requires a separate address for every unit including a JADU; a JADU needs an efficiency kitchen and, if it shares a bathroom, an interior door to the house), and impact fees are included in the bid or billed separately.
How long does it take to build an ADU in Los Angeles?
Plan for the permit review (The city must tell you within 15 business days whether the application is complete and must approve or deny it within 60 days of a complete application, or it is deemed approved (Gov. Code 66317(a) as amended by SB 543, in force January 1, 2026; LAMC 12.22 A.33(c)(2); ZA Memo 143 Q.24). If the ADU is filed with a new house, the ADU permit may wait for the house permit. LADBS publishes no average ADU plan-check turnaround; the Standard Plan Program is described only as shortening plan check in Los Angeles) plus construction. Most detached ADUs take 4-8 months of construction after permits are issued; garage conversions and prefab units are often faster. Ask each builder for a realistic schedule and what could delay it.
Get Free ADU Builder Quotes in Los Angeles
Compare bids from experienced local Los Angeles ADU builders. Free, no obligation.
Get Free Quotes →