ADU Builder in Los Angeles: Permits, Cost & Timeline

AngryFarmer
June 24, 2026

Hiring an ADU builder in Los Angeles is the fastest way to add living space, rental income, or room for family without buying a new property. But between LADBS permits, California’s evolving ADU laws, and a construction process that can run 6 to 14 months, knowing what to expect protects your budget and your timeline. This 2026 guide from HomeSense Construction & Remodeling walks you through ADU types, costs, permits, and how long the whole project really takes.

What an ADU Builder in Los Angeles Actually Does

An accessory dwelling unit (ADU) is a self-contained second home on your lot. A full-service ADU builder handles design, engineering, permitting, and construction under one roof, so you are not juggling separate architects, plan-checkers, and subcontractors. There are three main types:

Detached ADU — a stand-alone structure up to 1,200 sq ft of interior living space. Most popular for rental income and the highest resale value.
Attached ADU — built onto your existing home, up to 1,000 sq ft or 50% of the main house, whichever is larger.
Junior ADU (JADU) — up to 500 sq ft carved out of the existing house, often a converted bedroom or garage conversion.

ADU Cost in Los Angeles (2026)

In 2026, ADUs in Los Angeles run roughly $150 to $450 per square foot, with detached units averaging $250 to $400 per square foot. Typical all-in budgets:

Detached ADU (600–1,200 sq ft): $200,000–$360,000
Attached ADU (800–1,000 sq ft): $200,000–$350,000
Garage conversion ADU: $80,000–$200,000
Junior ADU (JADU): $60,000–$130,000

Permit fees alone range from $4,000 to $15,000 depending on size and type, plus a 10% General Plan Maintenance Surcharge as of June 2026. One key savings: California exempts any ADU under 750 sq ft of interior space from local impact fees. For a full breakdown, see our ADU cost in Los Angeles guide.

Permits and 2026 California ADU Laws

Recent state laws have made ADUs far easier to build. AB 976 permanently removed owner-occupancy requirements for standard ADUs, so you can rent out both the main home and the ADU. Under SB 543, size limits now measure interior livable space only — exterior walls and stairs no longer count against your square footage. JADUs that share a bathroom with the main home still require owner-occupancy under AB 1154.

Most LA ADU projects are permitted through LADBS. Plans using the LADBS Standard Plan Program (pre-approved designs) are often permitted in 21 to 30 days, while custom plans take 30 to 60 days per review cycle, or 8 to 16 weeks with revisions. A licensed ADU builder manages plan-check corrections so the legal clock keeps moving.

How Long Does It Take to Build an ADU?

Plan on 6 to 14 months from start to certificate of occupancy:

Design & engineering: 6–12 weeks
Permitting: 8–16 weeks (4–6 weeks with pre-approved plans)
Construction: 4–6 months for a detached 600–800 sq ft unit; 3–6 months for a garage conversion

One real-world timing note for 2026: LADWP electrical service approvals are currently running about 3 months, which can stretch beyond the 60-day legal review window. Choosing a pre-vetted design can shave 8 to 12 weeks off the schedule.

Choosing the Right ADU Builder in Los Angeles

Verify the contractor holds an active California license, carries insurance, and has built ADUs in your city. HomeSense Construction & Remodeling is a licensed general contractor (CA License #1125001) serving the greater Los Angeles area within about 60 miles — Los Angeles, Orange, Ventura, San Bernardino, Riverside, and Kern Counties — including West Hills, Woodland Hills, Northridge, Encino, Sherman Oaks, Burbank, Glendale, Pasadena, Long Beach, Anaheim, Santa Ana, Riverside, San Bernardino, Oxnard, Santa Clarita, Simi Valley, and Thousand Oaks. Explore our general contractor services or compare an addition with our room addition cost guide.

Frequently Asked Questions

Do I need a permit to build an ADU in Los Angeles?
Yes. Every ADU requires a building permit through LADBS, plus electrical, plumbing, and mechanical sign-offs. Your builder typically pulls these on your behalf.

Can I rent out my ADU?
Yes. As of 2024, standard ADUs no longer require owner-occupancy, so you can rent both the main home and the ADU (long-term; short-term rules vary by city).

How much value does an ADU add?
ADUs typically deliver strong ROI in LA through rental income and added square footage, often recovering a large share of build cost at resale.

What is the cheapest type of ADU?
Garage conversions and JADUs are the most affordable because they reuse existing structure and footprint.

Get a Free ADU Estimate

Ready to start? Call HomeSense Construction & Remodeling today at (818) 300-3422 for a free, no-obligation ADU estimate, or request your free estimate online. We design, permit, and build ADUs across the greater Los Angeles region.

Related Los Angeles Remodeling & Cost Guides

Planning a project anywhere in the greater Los Angeles area? Call HomeSense Construction & Remodeling at (818) 300-3422 for a free estimate.