How Much Does an ADU Cost in Los Angeles? (2026)

If you are pricing an ADU in Los Angeles in 2026, here is the honest answer up front. A garage conversion typically runs roughly $100,000 to $180,000 all-in. A detached new-build ADU typically runs roughly $250,000 to $450,000, which usually works out to somewhere around $333 to $600 per square foot once design, engineering, permits, and construction are counted. These are typical market ranges, not quotes. Your lot, your garage, and your finish choices will move the number.

The gap between the two paths is simple to explain. A conversion starts with a structure that already exists: a slab, walls, and a roof that need to be brought up to habitable code. A detached build starts with dirt, so you pay for a foundation, framing, a roof, and full utility runs before a single finish goes in. This guide breaks down what each budget tier actually buys, the factors that swing pricing the most, where cutting corners backfires, and what a realistic schedule looks like from first sketch to final inspection.

Garage Conversion ADU Costs by Tier

Most Los Angeles garage conversions land between $100,000 and $180,000. Where you fall in that range depends on the condition of the existing structure and how far you take the finishes.

Essential conversion: roughly $100,000 to $130,000

This tier turns a sound, dry garage into a clean, code-compliant studio or one-bedroom unit.

• Structural upgrades to the existing slab, walls, and roof as required by code
• New insulation, drywall, and interior paint throughout
• One full bathroom with standard fixtures and tile
• Compact kitchenette with stock cabinets and basic appliances
• Mini-split heating and cooling
• Durable standard flooring such as luxury vinyl plank
• Egress windows, smoke and carbon monoxide detection, and required fire separation

Mid-range conversion: roughly $130,000 to $155,000

This is where most homeowners end up: a unit that feels like a small home rather than a converted garage.

• Full kitchen with quartz counters and semi-custom cabinets
• Upgraded bathroom with a tiled shower and better fixtures
• New electrical subpanel and upgraded wiring
• Better windows and exterior doors
• Engineered flooring and upgraded lighting
• A private entry and basic exterior work so the unit reads as a residence

High-end conversion: roughly $155,000 to $180,000

The top tier is common when the unit will house family long-term or target premium rental income.

• Custom cabinetry and designer finishes throughout
• Vaulted ceilings where the existing framing allows
• In-unit laundry
• High-efficiency HVAC and water heating
• Sound insulation between the unit and the main house or neighbors
• Exterior upgrades such as new siding, hardscape, and a defined private yard

Detached ADU Costs by Tier

Detached new builds in LA typically run roughly $250,000 to $450,000, or roughly $333 to $600 per square foot all-in. Square footage is the biggest lever, followed by finish level and site conditions.

Compact studio or one bedroom: roughly $250,000 to $320,000

• Roughly 400 to 600 square feet
• New foundation, framing, roofing, and complete building envelope
• One full bathroom and a complete kitchen
• Mini-split HVAC and tankless water heater
• Standard finish package
• Trenching and connections for water, sewer, and electrical
• Design, engineering, and permit costs

Mid-range one or two bedroom: roughly $320,000 to $390,000

• Roughly 600 to 900 square feet
• Upgraded kitchen and bathroom finishes
• In-unit laundry
• Better windows, insulation, and exterior materials
• More considered layouts, such as a separated bedroom wing or a work nook

High-end two bedroom: roughly $390,000 to $450,000

• Roughly 900 to 1,200 square feet, near the maximum for most lots
• Two bathrooms and a full-size kitchen
• Custom cabinetry, designer tile, and premium fixtures
• Higher ceilings, larger glazing, and stronger curb appeal
• Landscape and hardscape integration with the main yard

Complex hillside lots or unusually difficult utility runs can push past these figures, which is exactly why per-square-foot numbers alone can mislead you.

The Six Factors That Move ADU Pricing Most

Two identical floor plans can price out tens of thousands of dollars apart on different properties. These are the variables that matter most.

• Site conditions. Hillside lots in neighborhoods like Highland Park or Mount Washington often need retaining walls, deeper foundations, or engineered grading. Tight access that forces hand digging or small equipment adds labor on any lot.
• Utility capacity. Many older LA homes still run on 100-amp panels that need upgrading to serve a second dwelling. Long sewer runs, or a main line on the far side of the property, add real trenching cost.
• The existing garage. For conversions, a cracked slab, termite-damaged framing, or unpermitted past work can move a project from the low end of the range to the middle before a single finish is chosen.
• Size and plumbing count. Kitchens and bathrooms are the most expensive rooms per square foot. Adding a second bathroom moves the price more than adding a bedroom of the same size.
• Finish level. The spread between stock and custom cabinets, or standard and designer tile, compounds across an entire unit.
• Design and permitting path. A pre-approved standard plan usually moves through plan check faster and cheaper than a fully custom design. LADBS permitting timelines vary with project complexity and department workload, so build slack into your schedule either way.

Where Not to Cut Corners

There are smart places to save on an ADU, like choosing mid-range finishes or a simpler roofline. These are not those places.

• Foundation and structural work. Everything else sits on it. A conversion built over a compromised slab will telegraph that mistake through cracked tile and sticking doors for years.
• Waterproofing. Roofing, flashing, shower pans, and site drainage are cheap to do right and brutally expensive to fix after drywall and finishes are in.
• Electrical. Undersized panels and rushed wiring create safety issues and fail inspection. This is licensed-trade work, full stop.
• Permits. An unpermitted ADU cannot be legally rented, complicates insurance claims, and surfaces at sale. Legalizing after the fact almost always costs more than permitting correctly the first time.

A Realistic ADU Timeline in Los Angeles

Plan on design and engineering taking about one to three months, depending on how quickly decisions get made and whether the design is custom or based on a standard plan.

Permitting comes next, and this is where expectations matter. LADBS timelines vary by project type, plan quality, and current workload. Clean, complete submittals with fast responses to plan-check corrections move noticeably quicker than sloppy ones, but no builder controls the department’s queue, and anyone promising an exact approval date is guessing.

Construction itself runs about 10 to 14 weeks for a garage conversion and three to five months for a detached build. That is the window we put in writing. What varies is everything before it: design, engineering, and the city plan check queue, which no builder controls. Counting that front end, most homeowners are looking at roughly six to nine months from first meeting to keys. Weather, inspections, and material lead times can stretch the schedule, and we tell you when they do.

How Athenian Builders Prices ADU Projects

We do not price ADUs from a phone call, because the honest answer lives on your property. It starts with a free on-site walkthrough where we look at the garage or yard, the panel, the sewer path, and the access before talking numbers.

From there you get transparent, itemized line-item pricing. You see what the foundation costs, what the kitchen costs, what the utility connections cost, and you can adjust scope with real information instead of a single mystery total. Once scope is set, our ADU construction team in Los Angeles commits to a fixed price and a fixed timeline in writing, so the number you sign is the number you build to.

Athenian Builders Group is a licensed and insured California contractor, CSLB License #1045030, with a 5.0 Google rating, serving all of LA County. We respond the same business day, Monday through Friday, 8am to 5pm.

ADU Cost FAQ

Is a garage conversion always cheaper than a detached ADU?

Usually, but not always by as much as people expect. A garage with a bad slab, damaged framing, or awkward proportions can eat much of the savings, and occasionally demolishing it and building new in its footprint pencils out better. A walkthrough settles this question quickly.

Can I build an ADU in Los Angeles for under $100,000?

With design, engineering, permits, and licensed labor included, it is rare in today’s market. Bids far below the ranges in this guide usually signal missing scope, unpermitted work, or change orders waiting to happen. Compare bids line by line, not by the bottom number.

Do these ranges include design, permits, and utility connections?

Yes. The figures above are all-in market ranges covering design, engineering, city fees, utility connections, and construction. Every property is different, though, which is why no range, including this one, should be treated as a quote for your specific lot.

Get a Real Number for Your Property

If you are weighing a garage conversion against a detached build anywhere in LA County, from Sherman Oaks to Culver City, the fastest way to replace ranges with a real number is to walk the property with a builder. Call Athenian Builders at (310) 857-2520 or request a free on-site estimate. We respond the same business day, Monday through Friday, 8am to 5pm, and the walkthrough costs you nothing but an hour.

Permits and Title 24: What They Add to Your ADU Budget

There is no such thing as an unpermitted ADU worth building. Every ADU in Los Angeles requires full plans, plan check, and permits, whether you are in the City of LA under LADBS or a neighboring city like Burbank, Glendale, or Pasadena. The good news is that state law now requires cities to review a complete ADU application ministerially, generally within 60 days, so the approval path is more predictable than it used to be. After issuance, the project moves through staged inspections from foundation and framing through rough trades, insulation, and final.

Because an ADU is new construction, Title 24 applies in full. Your plans will include an energy compliance report covering insulation values, window performance, high-efficacy lighting, and efficient heating and cooling, which is why heat pump systems are now the default choice. Newly built ADUs also generally require rooftop solar under current code, with some exceptions, and that is a line item many first-time budgets miss entirely.

This is exactly where lowball bids hide their gap. Plan check fees, energy consultants, solar, and city fees vary by jurisdiction and unit size, and a bid that skips them is not cheaper, it is incomplete. An ADU built without permits cannot be legally rented, which defeats the point for most owners. Athenian Builders handles the plans, pulls the permits, manages every inspection, and shows the entire permit and compliance scope as its own line in your itemized fixed price before construction begins.

The Choices That Move Your ADU Price

Two ADUs with the same square footage can come in wildly different because the biggest cost drivers sit in the ground, in the trenches, and in the kitchen and bath spec. The figures below are typical LA market ballparks, not quotes, and your lot conditions will set the real number.

• Foundation and lot conditions: a flat lot with a standard slab on grade is the baseline. Sloped lots that need stem walls, grading, retaining, or engineered footings often add five figures before framing even starts.
• Utility runs and trenching: distance matters. Trenching for power, water, and sewer is commonly priced per linear foot, so a unit at the back of a deep lot costs meaningfully more to connect, and a main electrical panel upgrade, when required, often runs somewhere in the range of $3,000 to $10,000 or more.
• Ceiling height and roofline: a simple roof with standard ceiling heights is the most economical shell. Vaulted ceilings, taller wall plates, and complex rooflines add framing, engineering, and finish cost.
• Kitchen and bath spec inside the unit: this is the biggest swing you control. A clean builder-grade kitchen and bath keeps the budget tight, while matching the finishes of the main house can add tens of thousands to the same floor plan.

We price every one of these as its own line in the itemized estimate, so you know before breaking ground whether the money is going into the dirt, the utilities, or the finishes.

Financing available. Many Los Angeles homeowners fund this work with a HELOC, a cash-out refinance, or a renovation loan. See our guide to remodel financing options in Los Angeles.

Have an unpermitted unit already? Read our guide to legalizing an unpermitted ADU in Los Angeles.