ADU Design & Permitting Cost - Design, Permits and Build Under One Contract

How Much Does ADU Design & Permitting Cost in Los Angeles?

ADU design and permitting in Los Angeles typically runs $18,000 to $45,000 for a standard detached or attached unit, covering architectural drawings, structural engineering, and City of LA plan check fees. A simple garage conversion design-and-permit package often lands closer to $12,000 to $22,000, while hillside lots and larger two-story builds push past $50,000. That figure is separate from construction – design and permitting is the paperwork phase that gets your project legal, and it usually takes three to five months in the City of Los Angeles.

We’re Lodgewick ADU Builders, part of the Kingswell family of home-service companies, and we’ve spent years pulling ADU permits across Los Angeles. What we see again and again is homeowners surprised that the soft costs stack up before a single foundation is poured. This guide gives you real Los Angeles numbers, not a range so wide it tells you nothing.

Key Takeaways

• Full ADU design and permitting in Los Angeles: $18,000 – $45,000.
• Garage conversion design and permits: $12,000 – $22,000.
• City plan check and permit fees alone: $4,000 – $12,000 depending on size and location.
• Timeline from first sketch to issued permit: usually 3 – 5 months in the City of LA.
• Every Lodgewick project comes with a written price before work begins and The Kingswell Guarantee, the 365-Day Done Right Promise.

ADU Design & Permitting Cost Breakdown (2026)

Here’s what the line items actually cost across Los Angeles in 2026. These are design and permitting figures only – construction is quoted separately.

What pushes the number up: a steep or hillside lot in the Hollywood Hills or Mount Washington needs more engineering and often a geotech report. A lot with a large protected tree, or one in a Very High Fire Hazard Severity Zone, adds review layers. What pushes it down: a straight garage conversion on a flat lot on a standard residential street. We can usually bring those in at the low end of the range because there’s less to document. If you want to understand the full scope of what we handle, our ADU Design & Permitting in Los Angeles page walks through it end to end.

What Affects ADU Design & Permitting Pricing in Los Angeles

No two Los Angeles lots are the same, and the soft costs move with the site. Here are the factors we see swing the price most often.

• Lot topography. A flat lot in Palms or Canoga Park is straightforward to plan. A graded hillside lot in Sherman Oaks or Glassell Park needs retaining walls on the drawings, more structural work, and usually a geotechnical report. That alone can add $5,000 to $12,000.
• Unit type. A detached new-build ADU needs full permits and its own utility connections, so it costs more to design and permit than an attached unit or a garage conversion. A JADU is the cheapest route because a JADU (a junior ADU, a small unit built inside the existing house footprint) needs far less site work.
• Square footage. Plan check fees in Los Angeles scale with size and valuation. A 1,200 square foot unit costs meaningfully more to permit than a 500 square foot one.
• Zoning and overlays. Coastal zones, hillside ordinances, and HOA review all add layers. In neighborhoods like Hollywood Hills, Mount Washington, and Pacific Palisades, layered review adds both time and money.
• Fire hazard zones. Los Angeles has extensive Very High Fire Hazard Severity Zones. A unit in one of these zones needs additional review, which affects both the design and the permit timeline.
• Survey accuracy. If your lot lines are unclear or a prior addition wasn’t permitted, we have to document more before the city will issue anything. Catching this early saves money later.

Climate and geography matter here in a way they don’t in most cities. LA’s seismic rules mean structural engineering isn’t optional for detached units, and the hillside neighborhoods carry their own planning requirements. We factor all of that into the written price before you commit to anything.

Can You Design and Permit an ADU Without Hiring a Separate Architect?

Yes, and for most Los Angeles homeowners it’s the simpler route. A design-and-permit package bundles the architect, engineer, and permit work into one scope, so you’re not coordinating three vendors who don’t talk to each other. We handle the drawings, the structural stamp, the Title 24 documentation, and the plan check submissions as one job.

If you’ve already got an architect, we can build from their plans. But when the design work and the build come from under one roof, nothing falls through the gap when plan check comes back with corrections – and in Los Angeles, corrections are the rule, not the exception. Our team handles the corrections directly with LADBS and keeps the project moving.

How Long Does ADU Design and Permitting Take in Los Angeles?

Most Los Angeles ADU projects go from first sketch to issued permit in three to five months. Design and engineering take about four to eight weeks. Then LADBS plan check, corrections, and issuance add another six to twelve weeks depending on the queue and whether overlay reviews apply.

Garage conversions often move faster because there’s less structural review. Hillside and fire-zone projects take longer because each review layer has its own queue. An expediting service can trim weeks off the front and back ends, which is why we sometimes recommend it for tight timelines. Timelines in Los Angeles are slower than in many smaller cities in the county, partly because of the volume LADBS handles. If speed matters, starting the design early is the single biggest lever you have.

How to Save on ADU Design & Permitting in Los Angeles

You don’t have to overpay for the paperwork. These moves reliably keep costs down.

1. Choose a garage conversion or JADU where it fits. These need less engineering and less site documentation, so both design and permit fees drop. A JADU in particular reuses your existing footprint and skips a lot of the review.
2. Get your lot documents together first. A current survey and any prior permit records speed up plan check and cut the hours we spend researching your property.
3. Use a design-and-permit package. Bundling design, structural, and permitting avoids the markup you pay when separate vendors coordinate with each other.
4. Ask about standard plans. Pre-designed units from established manufacturers and brands can cut design time, though every plan still has to be adapted to your specific site and permitted locally.
5. Fix unpermitted work early. If a previous addition isn’t on record, dealing with it during design is far cheaper than dealing with it during build.

Free estimates are part of how we work. Call (254) 602-5618 and we’ll put a written design-and-permit price in front of you before anything starts – no price changes at the door.

Why Lodgewick’s Design and Permitting Work Comes With a Written Promise

Most contractors leave homeowners guessing. We don’t. Every Lodgewick project runs on The Kingswell Way: say the price before the work, show up in the window given, leave the place cleaner than we found it, put the guarantee in writing, and come back if it fails. That means a written price before design begins, a defined arrival window for every site visit, and background-checked, uniformed technicians who you always know are on your property.

We back it with the 365-Day Done Right Promise: if the work isn’t right, we come back and make it right, and that commitment is in writing on every project. For permitting, “right” means the drawings are accurate, the corrections get answered, and the permit is issued – not left hanging. A live person answers our phones 24 hours a day, seven days a week, so if you have a question about your build or your guarantee, you reach a human.

We also work hands-on with established ADU brands and materials, including Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie, so we can match a prefab or panelized approach to your lot, budget, and timeline rather than forcing one option.

FAQs – ADU Design & Permitting Cost

How much does ADU design and permitting cost in Los Angeles?

Expect $18,000 to $45,000 for a full ADU in Los Angeles, or $12,000 to $22,000 for a garage conversion. City plan check and permit fees alone run $4,000 to $12,000. Hillside and fire-zone lots run higher because of extra engineering and review. Call (254) 602-5618 for an exact quote – estimates are free.

Is it cheaper to design a garage conversion than a detached ADU?

Yes. A garage conversion design-and-permit package usually lands $6,000 to $12,000 lower than a detached unit because there’s no new foundation or site engineering. If your garage is on a flat lot, this is the least expensive legal path to added living space in Los Angeles.

Do I need a separate architect for an ADU in Los Angeles?

No. A design-and-permit package covers the architect, structural engineer, Title 24 documentation, and permitting for a single price, which is why it’s usually less expensive than hiring each separately. Most Los Angeles homeowners go this route.

How long does it take to get an ADU permit in Los Angeles?

Most projects take three to five months from first sketch to issued permit. Design and engineering run four to eight weeks, and LADBS plan check plus corrections add six to twelve weeks. Garage conversions typically move faster. Call (254) 602-5618 to talk through your timeline.

Are plan check or design corrections included in the price?

Yes. When you work with us, handling LADBS corrections is part of the job, not a surprise line item later. We submit, respond to corrections, and keep the permit moving under the written price we gave you at the start.

Is it cheaper to repair or replace my existing garage for an ADU?

Usually replace the structure if the existing garage has foundation or framing problems, and convert if the shell is sound. A structural assessment during design gives you a real number instead of a guess. We’ll put both options and their costs in writing so you can decide.

Get a Written ADU Design and Permitting Price for Your Los Angeles Lot

Design and permitting is the phase that makes your ADU legal and buildable, and in Los Angeles the soft costs are real – but they’re also predictable once someone looks at your actual lot. We’d rather give you a straight number than a vague range, and we put it in writing before any work starts. Bring us your address, and we’ll tell you what your property needs. Call (254) 602-5618 for a free estimate. A live person answers, day or night, and you’ll leave the call knowing exactly where your project stands. Lodgewick ADU Builders is part of the Kingswell family of home-service companies, and every location is independently owned and operated under The Kingswell Guarantee.

Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving Los Angeles since 2010.

Pricing reflects the Los Angeles market as of 2026. Lodgewick ADU Builders offers free estimates – call (254) 602-5618.