ADU in Los Angeles, CA
A Junior ADU & Interior Conversion in Los Angeles typically runs $85,000-$165,000 all-in, drawings through final inspection, while ADU Site Prep & Utilities adds $25,000-$75,000 depending on whether we’re upgrading a 60-amp panel in a 1950s Valley garage or pulling a new sewer lateral from an alley in South LA. We’re Ellery ADU Studio, a design-build practice with our Los Angeles office coordinating dispatch and scheduling locally. Call (424) 523-8492 for a free estimate with a written price before any work starts, per Haven Standard Clause 1.
Why Los Angeles Homes Are Different
Los Angeles sits in the highest seismic hazard zone in the continental United States, and every ADU here must meet California’s Title 24 energy standards plus rigorous shear wall, hold-down, and foundation requirements that add engineering and inspection costs rarely seen in non-seismic metros. The city’s predominant housing stock is post-WWII wood-frame construction from the 1940s through 1970s, with detached one- or two-car garages on alley-loaded lots across the San Fernando Valley, Eastside, and South LA flatlands. Most of these homes still carry original 100-amp or even 60-amp electrical service panels that must be upgraded before an ADU can be energized, and garage slabs from this era are commonly non-reinforced and undersized, requiring new footings or full slab replacement to meet current seismic and structural code before conversion.
On the alleys that bisect the flatland grid from Van Nuys to Watts, detached garages have no street frontage and often share utility easements. We routinely pull sewer laterals and new electrical service from the alley side rather than the street - a workflow that trips out-of-area contractors who don’t know that LA’s DWP and Bureau of Sanitation treat alley-fed connections under different inspection protocols than street-side hookups.
Our Main Los Angeles Services
Los Angeles homeowners call us most often for these three project types, each with its own dedicated page and pricing.
ADU Design & Permitting in Los Angeles
We produce the permit set as the core product, not an afterthought. In Los Angeles, this means navigating LADBS’s pre-approved Standard Plan Program or submitting custom drawings through the city’s specific permit portal, then managing the inspection scheduling backlog that defines project timelines here. Our permit sets include structural calculations for seismic compliance, Title 24 energy documentation, and photorealistic renderings so you know what you’re building before ground breaks. ADU Design & Permitting in Los Angeles.
Garage Conversion ADU in Los Angeles
The vast inventory of car-culture-era detached garages built between the 1940s and 1970s makes this the dominant ADU type in Los Angeles at a scale unmatched nationally. We assess slab condition, electrical service capacity, and alley versus street utility access to determine whether your garage is a candidate for conversion or requires full demolition and rebuild. Every conversion includes a written price before work starts and a 365-Day Done Right Promise. Garage Conversion ADU in Los Angeles.
New Detached ADU in Los Angeles
When the existing garage is too far gone or the lot allows a better-placed structure, we design and build new detached ADUs from foundation to final inspection. Los Angeles’s tiered ADU/multi-ADU rules and setback variances - the extra distance the city requires between your new ADU and the property line - require site-specific engineering that we handle in-house. We also specify prefab systems from brands including Abodu and Cover when speed and precision matter. New Detached ADU in Los Angeles.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Before
AfterJunior ADU & Interior Conversion in Los Angeles
Junior ADU & Interior Conversion in Los Angeles solves the problem of aging, underutilized interior space in homes built during the post-WWII boom, when floor plans were generous but legally separate units were never contemplated. With LA rents among the highest in the nation and state law preempting most local restrictions, homeowners are converting basements, attics, and attached rooms at record volume. Junior ADU & Interior Conversion is our most requested service in the city.
Room-to-ADU Conversion
Signs you need it
You have a 300-500 square foot attached room, sunroom, or former servant’s quarters with separate exterior access that could become a self-contained rental unit.
What it costs in Los Angeles
Room-to-ADU conversions in Los Angeles typically run $85,000-$140,000 all-in, including the permit set, seismic retrofit of shared walls, and Title 24 compliance.
How we do it
We survey the existing structure, design a kitchenette and wet bath layout that meets JADU code, produce the LADBS permit set, then build to the drawings with a documented photo record on every visit.
Interior JADU
Signs you need it
You want rental income without exterior construction, and your primary residence has a bedroom or wing that can be separated with a locking door while sharing systems with the main house.
What it costs in Los Angeles
Interior JADUs in Los Angeles typically run $75,000-$125,000, with lower utility costs because the unit shares existing electrical, plumbing, and HVAC with the primary residence.
How we do it
We verify your main panel has capacity for the additional load, design the interior partition and kitchenette to JADU standards, file the owner-occupancy affidavit with LADBS, and build with no exterior footprint change.
What Junior ADU & Interior Conversion Costs in Los Angeles
| Item | Typical range in Los Angeles |
|---|---|
| Room-to-ADU conversion (attached) | $85,000 - $140,000 |
| Interior JADU (shared systems) | $75,000 - $125,000 |
| Above-garage ADU (new floor system) | $120,000 - $185,000 |
Do I need a separate meter for a JADU in Los Angeles?
No. California state law allows JADUs to share electrical and gas meters with the primary residence, though we recommend a sub-meter for landlord-tenant clarity. Call (424) 523-8492 for an exact quote - estimates are free.
Can I convert my basement to an ADU in Los Angeles?
Yes, if ceiling height meets 7’6″ minimum and egress windows comply with current fire code; many 1940s-1960s basements in Los Angeles fall short and require excavation or benching. Call (424) 523-8492 for an exact quote - estimates are free.
ADU Site Prep & Utilities in Los Angeles
ADU Site Prep & Utilities in Los Angeles addresses the hidden infrastructure costs that derail projects: original 60-amp panels that can’t handle a second dwelling, non-reinforced garage slabs that fail structural review, and alley-fed sewer laterals that require Bureau of Sanitation approval separate from LADBS. ADU Site Prep & Utilities is where we eliminate surprises before construction starts.
Electrical Panel Upgrade
Signs you need it
Your home still has a 60-amp or 100-amp panel with no empty breaker slots, or the main disconnect shows heat damage or fuse remnants.
What it costs in Los Angeles
Electrical panel upgrades in Los Angeles typically run $4,500-$8,500 for 200-amp service, including LADBS permit, DWP coordination, and trenching if the meter needs relocation.
How we do it
We verify load calculations for the ADU, coordinate with DWP for service lateral sizing, pull the LADBS electrical permit, and install the new panel with documented photos before drywall closes it in.
Foundation & Grading
Signs you need it
Your garage slab is cracked, sloped toward the interior, or measures less than 4 inches thick with no rebar visible in core samples.
What it costs in Los Angeles
Foundation and grading work in Los Angeles typically runs $12,000-$28,000 for a garage conversion, including engineered footings, stem walls, and slab replacement to current seismic code.
How we do it
We engage a structural engineer for soils and seismic design, excavate to engineered depth, pour reinforced footings with hold-downs, and place a new 4-inch minimum slab with vapor barrier and edge insulation.
What ADU Site Prep & Utilities Costs in Los Angeles
| Item | Typical range in Los Angeles |
|---|---|
| Electrical panel upgrade (to 200A) | $4,500 - $8,500 |
| Foundation & grading (garage conversion) | $12,000 - $28,000 |
| Sewer lateral replacement (alley or street) | $8,000 - $18,000 |
Will I need DWP approval separate from LADBS?
Yes. DWP reviews electrical service capacity and may require a service lateral upgrade separate from LADBS structural and electrical permits; we coordinate both. Call (424) 523-8492 for an exact quote - estimates are free.
How long does site prep take before construction starts?
Site prep and utilities typically add 4-8 weeks to the front of a Los Angeles ADU project, with DWP and Bureau of Sanitation scheduling often the pacing factor. Call (424) 523-8492 for an exact quote - estimates are free.
Brands We Service in Los Angeles
We specify and coordinate prefab and modular systems from James Hardie, Abodu, and Cover within our single-contract design-build model, with parts and expertise stocked locally for rapid turnaround. See our brands for the full list.
Pricing for ADU in Los Angeles, CA
| Service | Typical range in Los Angeles |
|---|---|
| Junior ADU & Interior Conversion | $75,000 - $185,000 |
| Room-to-ADU conversion | $85,000 - $140,000 |
| Interior JADU | $75,000 - $125,000 |
| Above-garage ADU | $120,000 - $185,000 |
| ADU Site Prep & Utilities | $25,000 - $75,000 |
| Electrical panel upgrade | $4,500 - $8,500 |
| Foundation & grading | $12,000 - $28,000 |
| Sewer lateral replacement | $8,000 - $18,000 |
In Los Angeles, price drivers include seismic engineering for soft-story conditions, alley-fed utility connections requiring dual-agency coordination, and slab replacement on non-reinforced 1950s-1970s garages. Every project is quoted with a written price before any work begins, per Haven Standard Clause 1; no change orders, no door-side upsells.
Neighborhoods We Serve in Los Angeles
We serve homeowners across Los Angeles from our local office, with crews dispatched to all major residential zones. Response scheduling is typically within 48 hours for site visits.
- Van Nuys
- Silver Lake
- Watts
- Crenshaw
- Eagle Rock
Service Area - Cities Near Los Angeles
Our crews work throughout the Los Angeles metro, including Culver City, CA, West Hollywood, CA, Beverly Hills, CA, and Glendale, CA. Dispatch and scheduling are coordinated from our Los Angeles office.
Serving Los Angeles, CA - Our Local Coverage Area
We’re based in the Los Angeles area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU in Los Angeles
Standard Plan ADUs typically clear in 60-90 days; custom designs take 90-150 days depending on LADBS backlog and rounds of correction. We track every submittal through the city’s portal and resubmit within 48 hours of any correction letter.
California state law preempts most HOA restrictions on ADUs, though HOAs may still enforce design guidelines for exterior materials and colors; we review your CC&Rs during the estimate phase.
We pull all permits as part of our single-contract model, including LADBS structural, electrical, and plumbing permits plus DWP and Bureau of Sanitation utility approvals; the permit costs are itemized in your written quote.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Los Angeles Customers Say
"The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N."They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T."The permit set and the build were one contract with one number. Our neighbours used two firms and spent a year watching them blame each other."
- Helena V.