Garage Conversion ADU Cost - One Fixed Price, Permits Handled

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How Much Does Garage Conversion ADU Cost in Woodland Hills?

A garage conversion ADU in Woodland Hills typically costs $95,000 to $165,000 for a complete permitted conversion in 2026, including design, construction, and standard finishes. Smaller studio conversions can land near $80,000, while a fully detached garage with a new foundation and upgraded systems can push past $190,000. The number that matters most is the written price you get before work starts, because Woodland Hills has real variables: hillside setbacks, older slab conditions, and the city’s specific ADU inspection requirements all move the final figure.

Garage conversions run $215 to $310 per square foot in Woodland Hills, depending on whether you’re working with an attached garage or a detached structure that needs more infrastructure. Attached conversions cost less because the walls, roof, and one side of the electrical are already there. Detached conversions cost more because everything from the foundation up has to be brought to code. The spread between those two numbers is where most of the confusion in online estimates comes from.

We’ve been building ADUs and garage conversions in the Woodland Hills area long enough to know that homeowners want a real number, not a range that spans six figures with a shrug. This guide puts actual dollar figures on the table for 2026, names the factors that move them, and tells you what to ask a contractor before you sign anything.

Garage Conversion ADU Cost Breakdown (2026)

Here’s what you can expect to pay for a garage conversion ADU in Woodland Hills, line by line. These figures reflect our current pricing as of 2026 for the Woodland Hills market and assume a standard 400-square-foot two-car garage with a bathroom, kitchenette, and one bedroom.

• Design and architectural drawings: $4,000 to $9,000. This covers the plans you submit to the city, including any hillside drainage calculations if you’re on a slope.
• Permitting fees (City of Los Angeles, Woodland Hills area): $3,500 to $7,000. LADBS plan check, school district fees, and the ADU-specific surcharges are all in this range.
• Demolition and site prep: $3,000 to $6,500. Removing the garage door, grinding the slab if needed, and hauling debris.
• Foundation and slab work: $2,000 to $14,000. This is the big swing line. A slab in good condition needs almost nothing. A slab with cracking or no vapor barrier needs full replacement, and hillside garages sometimes need retaining or drainage work.
• Framing and structural upgrades: $6,000 to $18,000. Older garages in Woodland Hills were not built to residential code. Expect ceiling joist replacement, wall reinforcement, and possibly a new roof structure.
• Plumbing (rough-in and fixtures): $8,000 to $18,000. Running a new sewer line from the garage to the main, plus supply lines for a bathroom and kitchenette.
• Electrical (panel, wiring, fixtures): $7,000 to $15,000. A new subpanel is usually required. If your main panel needs an upgrade, add $4,000 to $6,000 more.
• Insulation and drywall: $6,000 to $11,000. Exterior walls get upgraded insulation for sound and fire code. This is not a line item to cut.
• Flooring: $3,000 to $8,000. Durable plank flooring runs about $7 to $18 per square foot installed in this market, depending on material.
• Kitchenette (basic cabinet, sink, cooktop or microwave, counter): $9,000 to $20,000. A full kitchen with dishwasher and range pushes toward the top of that range.
• Bathroom (shower, toilet, vanity, tile): $12,000 to $25,000. This includes waterproofing and ventilation. Woodland Hills building code requires a properly vented bathroom in any ADU.
• HVAC (mini-split heat pump): $5,000 to $9,000. Valley summers make cooling non-negotiable, and a ductless mini-split is the standard solution for a converted garage.
• Drywall texture and painting: $3,500 to $7,000. Walls, ceiling, and trim.
• Windows and doors: $4,000 to $10,000. Replacing the garage door with a wall and adding egress windows is usually required. French doors or a slider add to the line.
• Exterior stucco or siding match: $4,000 to $9,000. Matching the existing home’s exterior so the conversion looks like it was always part of the house.
• Landscaping and drainage (if hillside): $0 to $12,000. Hillside lots in Woodland Hills can trigger drainage requirements that flatter lots never see.
• Contractor general conditions and project management: $8,000 to $15,000. This covers supervision, scheduling, cleanup, and coordination with the city.

Total realistic range: $95,000 to $165,000 for a standard 400-square-foot conversion. A basic studio conversion without a full kitchen might land at $80,000. A high-end conversion with premium finishes, custom casework, and a full bathroom with soaking tub can reach $190,000.

The single largest cost variable in Woodland Hills is your garage’s condition. Garages built in the 1950s and 1960s, which is most of the housing stock south of Ventura Boulevard, were never designed for living space. The slab is thinner, the walls lack shear strength for earthquake code, and the electrical service to the garage is usually a single circuit. A 1962 garage in the Woodland Hills flats will need more structural work than a 1990s garage in the same neighborhood, and the price difference shows up in the framing and foundation lines.

What Affects Garage Conversion ADU Pricing in Woodland Hills

• Attached vs. detached garage: An attached garage shares two walls, a roof, and one side of electrical with your house. A detached garage is a standalone structure that needs everything run to it: sewer, water, gas, electrical, and sometimes a new roof system. Detached conversions in Woodland Hills run $30,000 to $50,000 more than attached for the same square footage.
• Hillside grading and drainage: Woodland Hills includes some of the steepest buildable lots in Los Angeles. If your garage sits below street level or against a slope, the city will require drainage calculations and possibly retaining work. We have seen hillside drainage requirements add $8,000 to $18,000 to a project that would sail through on a flat lot in the south Valley.
• Garage age and condition: Pre-1970 garages in Woodland Hills were frequently built with unreinforced masonry or thin slabs. The seismic retrofit requirements for a converted living space mean those garages need structural upgrades that newer garages skip. A 1955 garage with a cracked slab and a sagging roofline will cost more to convert than a 2005 garage that is basically a fireproof shell.
• Plumbing distance to the main line: The cost of running a new sewer line from your garage to your house’s main waste line is measured in feet. A garage 20 feet from the main costs $4,000 to $6,000. A detached garage 80 feet away, across a driveway and through landscaping, costs $10,000 to $16,000. The city requires proper slope on the line, which sometimes means trenching deeper on hilly properties.
• Electrical service capacity: A garage conversion ADU needs its own subpanel. If your main panel is a 100-amp panel from the 1960s, you’re likely looking at a full panel upgrade to 200 amps before the ADU can be wired. Plan on $4,000 to $6,000 for the panel itself, plus LADWP coordination time which can add weeks to the schedule.
• Kitchen and bathroom scope: A wet bar with a mini-fridge and a microwave costs half of a full kitchen with a gas range, dishwasher, and full-size refrigerator. A bathroom with a walk-in shower costs more than one with a standard tub-shower combo. Every appliance and fixture you add moves the price.

One factor that does not move the price as much as people expect is square footage. A 350-square-foot garage conversion does not cost 15% less than a 400-square-foot conversion. The fixed costs, such as permits, design fees, plumbing taps, and electrical panel work, stay the same. The variable costs, like drywall and flooring and paint, scale down modestly. The result is that smaller conversions have a higher cost per square foot. You might see $310 per square foot on a 350-square-foot studio and $240 per square foot on a 500-square-foot one-bedroom.

Woodland Hills Specific Considerations

Woodland Hills sits across the Santa Monica Mountains from the rest of Los Angeles, and that geography shows up in the permit process. Many homes north of Ventura Boulevard sit on slopes that trigger the city’s Hillside Construction rules, which add grading review and drainage requirements to a standard garage conversion. Homes south of Ventura Boulevard, in the flats near Topanga Canyon Boulevard and Canoga Avenue, typically convert with fewer complications.

Most homes in Woodland Hills fall under the City of Los Angeles ADU Ordinance, which has been updated several times since 2019. The current rules allow garage conversions on any lot zoned for single-family or multifamily residential use. The city waives parking replacement requirements for ADUs within walking distance of a major transit stop. In practice, most garage conversion ADUs in Woodland Hills do not trigger parking replacement, but if your home is over one mile from a transit stop, confirm this with your contractor before you commit.

The city also requires that any conversion of a garage into living space meet the full residential building code, not the looser standards that applied to the original garage build. That means fire-rated walls if the garage is attached to the house, seismic anchoring, insulation, and egress windows in sleeping areas. A permitted garage conversion in Woodland Hills is a full residential build with a residential certificate of occupancy at the end.

We have done enough of these in Woodland Hills to know what the inspector looks for. The LADBS inspector will check the slab elevation for flood exposure, the shear wall nailing pattern, the bathroom fan ventilation, and the smoke and carbon monoxide detector placement. These are not optional upgrades. They are the difference between a permitted ADU you can rent legally and an unpermitted conversion that becomes a liability when you sell the house.

How the Build Method Affects the Price

There are three ways to build a garage conversion ADU in Woodland Hills, and the method changes both the price and the timeline.

Conventional Stick-Built Conversion

This is the standard approach. We frame the new walls inside the existing garage structure, reinforce everything to residential code, and build the bathroom and kitchen on site. On a 400-square-foot garage, a conventional conversion takes 14 to 18 weeks from permit approval to certificate of occupancy. It gives the most design flexibility and typically costs $215 to $280 per square foot. This is the default, and it’s what most of our Woodland Hills clients choose because they want a space that looks like it belonged to the house from day one.

Prefab Panel or Modular ADU (Built Inside the Garage Shell)

Some manufacturers, including Abodu, Cover, and Plant Prefab, offer panelized or modular systems that can be assembled inside an existing garage shell faster than a conventional build. The panels arrive with insulation, wiring chases, and window openings pre-cut. Assembly takes two to three weeks on site instead of six to eight. The cost runs $230 to $310 per square foot, roughly 5 to 15% more than stick-built for the structure, but the schedule savings can offset carrying costs and hassle. We work with Abodu, Cover, Dvele, Mighty Buildings, Boxabl, and Plant Prefab when a client wants the prefab route.

Prefabricated Unit Replacing the Garage (Demolish and Install)

If the garage is in bad enough condition, the math sometimes favors demolishing it and installing a prebuilt ADU from a manufacturer like Boxabl or Plant Prefab. In Woodland Hills, this approach works on hillside lots where the existing garage has serious foundation problems. The site work for the new unit runs $20,000 to $50,000, and the unit itself ranges from $90,000 to $140,000 for a one-bedroom. Total: $130,000 to $190,000. It is not usually the cheapest path for a healthy garage, but for a collapsing one it can beat a rebuild.

How to Save on a Garage Conversion ADU in Woodland Hills

There are legitimate ways to keep the price down without cutting corners that will cost you later.

• Keep the kitchen as a kitchenette. A full kitchen with a gas range, dishwasher, and full-size refrigerator adds $8,000 to $12,000 over a compact kitchenette. Consider a two-burner induction cooktop, a microwave, and an under-counter refrigerator. The ADU still counts as a dwelling unit, and you cut a real chunk of cost.
• Use a standard bathroom layout. A 5-by-8 bathroom with a standard tub-shower combo, a vanity, and a toilet is the most efficient layout to plumb and tile. Walk-in showers, double vanities, and custom tile inlays move the price up fast.
• Match the existing finishes instead of upgrading. If your main house has basic baseboards, paint-grade trim, and standard door hardware, matching those in the ADU saves $3,000 to $5,000 compared to installing higher-end finishes in a small space.
• Convert the garage in its existing footprint. The cheapest conversion is the one that stays within the existing four walls. Adding square footage with an exterior bump-out triggers new foundation work, new roof lines, and a longer permit review. A 400-square-foot garage converted at 400 square feet costs less than a garage with a 60-square-foot addition.
• Schedule during the slower season. Most homeowners start ADU projects in spring and summer. Our pricing and scheduling are more flexible in the fall and winter months. A November start in Woodland Hills can mean a shorter wait and occasionally a better rate on some trade work.

The savings that matter are the ones that don’t show up in the line items: avoiding a contractor who lowballs the estimate and then sends change orders. At Fielding ADU Woodland Hills, the price goes in writing before any work starts. The number you approve on day one is the number on the final invoice. That’s The Garrison Code: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year. If you’re comparing bids, ask each contractor whether their estimate is a fixed price or an estimate that can move. The answer tells you a lot.

Garage Conversion ADU vs. Building a Backyard ADU: Cost Comparison

Woodland Hills homeowners sometimes assume a garage conversion is always the cheaper option. It usually is, but not always. A new detached ADU in the backyard runs $350 to $550 per square foot in Woodland Hills. A garage conversion runs $215 to $310 per square foot. On a 400-square-foot project, that’s the difference between roughly $110,000 and roughly $180,000.

The garage conversion wins on price because the shell already exists. The roof, most of the walls, and part of the foundation are already standing. A backyard ADU starts with a blank lot and needs everything: foundation, framing, roof, all four walls, and all utility connections run from scratch.

But there are situations where a backyard ADU makes more sense despite the higher cost. If you use your garage for parking and the alternative is street parking on a narrow Woodland Hills road, the loss of the garage has a real cost in convenience and possibly in home value. If your garage is detached and in poor condition, the cost of structural repair can narrow the gap. And if your lot is large enough to place a backyard ADU away from the main house, you gain separation that a garage conversion cannot provide.

The honest answer: most Woodland Hills clients who have a garage in good shape choose the conversion because the cost difference is $60,000 to $80,000. Clients with a garage that is falling apart or a strong preference to keep their covered parking choose a backyard unit. Both are legal, both are permitted, and both work.

Permitting Timeline in Woodland Hills

The City of Los Angeles Department of Building and Safety (LADBS) handles permits for Woodland Hills. A standard garage conversion ADU permit takes between 8 and 14 weeks for plan check approval after submission, provided the plans are complete and no corrections are required. Hillside lots, properties in designated fire zones, and garage conversions in historic overlay districts can add 4 to 8 weeks.

The permit fees you’ll pay are set by LADBS and are based on the valuation of the work. For a garage conversion ADU valued at $120,000, expect permit fees in the $3,500 to $7,000 range, including the school district fee that applies to residential additions in Los Angeles. These fees are paid directly to the city and are a separate line item from your contractor’s bid.

Once the permit is approved, construction on a standard garage conversion takes 14 to 18 weeks. The inspection sequence includes foundation, framing, plumbing, electrical, insulation, and a final inspection that must be passed before the city issues the certificate of occupancy. Each inspection happens on the city’s schedule, not ours, which is why we build the permit timeline into every project schedule in writing.

Rental Income and ROI for Garage Conversion ADUs in Woodland Hills

Woodland Hills rents for one-bedroom ADUs currently run $2,200 to $2,800 per month, depending on finishes, location, and whether the unit has its own entrance. A $120,000 garage conversion renting at $2,400 per month generates $28,800 per year in gross rent. That’s a gross yield in the 20% range, which is far beyond what most passive investments return.

From a resale perspective, a permitted ADU adds value to a Woodland Hills home in proportion to the rent it can generate and the quality of the build. A permitted conversion with its own address, separate entrance, and legal certificate of occupancy adds more than an unpermitted conversion that a buyer’s lender will not finance. We have seen unpermitted conversions become the reason a sale falls apart in escrow when the appraisal flags the missing permits.

The financial case for the garage conversion assumes the conversion is permitted. An unpermitted conversion cannot legally be rented, cannot be counted as square footage in a listing, and can trigger code enforcement fines if the city finds it. The savings from skipping permits never survives contact with a real estate transaction.

Checklist: What to Ask Any Contractor Before You Sign

• Is the price fixed in writing before work starts? If the contractor will not put the price in writing and sign it, walk away. A written price is the only protection you have against a bill that grows in month three.
• What is the permit status of your previous garage conversion ADUs? Ask to see a certificate of occupancy from a completed project. A contractor who cannot produce one has not finished the city process before.
• Who is on my job site? Ask whether the crew is background-checked. At Fielding ADU Woodland Hills, every technician arrives in uniform and has been background-checked before they set foot on your property.
• What is the guarantee, and is it in writing? We back every ADU and garage conversion with the 365-Day Done Right Promise. The Garrison Standard covers workmanship defects for 365 days; if something fails, we come back and make it right at no charge. Get whatever guarantee your contractor offers on paper.
• Will you handle the permit process from start to finish? The permit process in Los Angeles is not a homeowner-friendly experience. A contractor who expects you to pull the permit is a contractor who does not want the liability. We handle the entire LADBS process for our Woodland Hills projects.

FAQs – Garage Conversion ADU Cost

How much does a garage conversion ADU cost in Woodland Hills?

A garage conversion ADU in Woodland Hills costs $95,000 to $165,000 for a standard 400-square-foot conversion in 2026, including permits, design, and finishes. Smaller studio conversions can be built for around $80,000, and high-end conversions with premium fixtures and full kitchens can reach $190,000. For a fixed price on your specific garage, call (559) 254-0116 and we’ll put the number in writing before any work starts.

Is it cheaper to convert a garage or build a new ADU in Woodland Hills?

Converting a garage costs $215 to $310 per square foot, while building a new backyard ADU costs $350 to $550 per square foot. On a 400-square-foot project, the garage conversion saves $60,000 to $80,000. The exception is a detached garage in very poor condition, where structural repairs can narrow the gap enough that building new becomes competitive.

How long does a garage conversion ADU take in Woodland Hills?

Expect 8 to 14 weeks for LADBS permit approval and 14 to 18 weeks for construction on a standard garage conversion. A complete project from signed contract to certificate of occupancy runs 5 to 8 months, depending on hillside review requirements and the city’s inspection schedule.

Do I need a permit to convert my garage into an ADU in Los Angeles?

Yes. The City of Los Angeles requires a building permit for any garage conversion into living space, and the work must pass all residential code inspections before a certificate of occupancy is issued. Unpermitted conversions cannot legally be rented and become a liability when you sell or refinance the property. We handle the full LADBS permitting process for every Woodland Hills project.

Can I convert my garage into an ADU if it’s detached?

Yes, detached garage conversions are permitted in Woodland Hills, but they cost $30,000 to $50,000 more than attached conversions because utilities, foundation upgrades, and sometimes a new roof structure must be added. The condition of the detached garage’s slab and framing determines whether the structure can be reused or needs to be rebuilt.

What’s the cheapest way to build a garage conversion ADU in Woodland Hills?

The lowest-cost approach is a studio or one-bedroom conversion within the existing garage footprint, using a kitchenette instead of a full kitchen and standard bathroom fixtures. That configuration can land near $80,000. The price goes up from there with every structural repair, hillside drainage requirement, and luxury finish.

Ready to Price Your Garage Conversion?

The only way to get a real number for your Woodland Hills garage is to have someone look at it. The condition of the slab, the distance to the sewer line, the state of the electrical panel, and the slope of your lot all move the final figure. An online calculator cannot see those things. A contractor who quotes you over the phone without seeing the garage is guessing.

Fielding ADU Woodland Hills builds garage conversion ADUs in Woodland Hills with the price in writing before any work starts, the permit handled by us, and a one-year written guarantee on every project. Reed Calloway leads our team, and the same Garrison Code applies to every job: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year.

Call (559) 254-0116 for a free estimate. A live person answers, day or night. We’ll schedule a walkthrough of your garage, give you a written price, and tell you exactly what the city will require for your specific lot.

Written by Reed Calloway, Owner at Fielding ADU Woodland Hills, building garage conversions and ADUs in Woodland Hills since 2006.

Pricing reflects the Woodland Hills market as of 2026. Fielding ADU Woodland Hills offers free estimates – call (559) 254-0116.