How To Permit an Unpermitted ADU in Los Angeles [2025 Guide]

To legalize an unpermitted ADU in Los Angeles, you must apply for an "as-built" permit through the Department of Building and Safety, which requires submitting plans prepared by a licensed professional, scheduling inspections, and making any necessary code-compliance upgrades.

New 2025 rules, including Assembly Bill 2533, give Los Angeles homeowners a faster path to legalize an unpermitted ADU with fewer fines and a permit review capped at 60 days.

For many homeowners with an unpermitted ADU, 2025 is the right time to bring the unit into compliance and move toward a legal ADU with fewer surprises.

This guide explains how to permit an unpermitted ADU in Los Angeles from the first zone check through final inspection. You will find a step-by-step plan, current 2025 rules, and practical ways to cut delays. You'll learn:

• Zoning checks that confirm eligibility and common site constraints
• The legalization process for a retroactive permit and how plan check works
• Inspections you can expect, typical correction items, and sequencing
• Permit fees, timelines, and where 2025 changes save time
• How LADU manages the legalization process for you

By the end, you will know how to legalize an unpermitted ADU, what a retroactive permit requires, and how to move through inspection with fewer delays.

At LADU, our in-house team handles ADU design and ADU building permits and then arranges ADU construction and upgrades through licensed partners under one coordinated workflow so you can legalize your ADU with confidence. Book your free consultation today.

One Team. One Contract. One Goal.

What Counts as an Unpermitted ADU and Consequences

Definition and Common Types of Unpermitted ADUs

An unpermitted ADU is a secondary dwelling that was built or converted without a valid ADU permit or without passing final inspection. Common types include detached backyard units, attached in-law suites, garage conversions, and junior ADUs carved from the main house.

If the space is used as a residence and it never received a final sign-off from the city, it is an unpermitted ADU.

In Los Angeles, the term can cover a wide range of unpermitted dwelling unit conditions, from simple garage conversions with minimal work to full accessory dwelling units with kitchens and baths.

Unpermitted ADU: Risks, Fines, and Orders To Comply

Keeping an unpermitted ADU can trigger several issues:

• LADBS violation notices and orders to comply that require you to legalize or stop use
• Fine exposure if you ignore notices or fail to meet basic safety standards
• Risk of utility shutoffs when hazards exist or when illegal taps are found
• Problems when selling or refinancing, since lenders and buyers ask for permits and final inspections
• Insurance gaps, since carriers can deny claims tied to illegal work or uninspected systems
• A tenant may be able to legally stop paying rent without vacating the illegal ADU

Legalizing an unpermitted ADU closes these gaps and sets up a safer, more predictable path for rentals or family use.

How ADU Legalization Protects the Homeowner

A retroactive permit adds structure to the process. You submit plans, respond to the plan check, perform correction work, and pass inspection. This protects the homeowner and the tenant.

You gain clear documentation, safer systems, and a legal ADU that supports appraisal and refinancing. For many property owners, legalization also results in rent control exemptions for new ADUs and clarifies future maintenance and upgrade paths under current building codes.

2025 Rules That Make ADU Building Permits Simpler

AB 2533 and Retroactive ADU Permit Paths

Assembly Bill 2533 (AB 2533) strengthens legalization options for an unpermitted dwelling unit. The law supports retroactive permit paths for units built before 2020 that meet a basic safety bar.

In practice, this means a unit that can show safe structure, fire separation where required, working smoke and CO alarms, proper egress, and reasonable electrical and plumbing safety can qualify for reduced penalties while it moves through plan check and correction work.

If you plan to legalize an unpermitted ADU, AB 2533 can reduce friction and speed the path once life-safety items are addressed.

60-Day Ministerial Review and Pre-Approved ADU Plans

All ADU permits in California are ministerial under state law. In 2025, cities must complete the initial review within 60 days. For an unpermitted ADU that is being legalized, the same clock and process apply once your submittal is complete.

Some cities and counties publish pre-approved plans. In Los Angeles, using a plan set aligned with local standards can shorten permit approval time for a new ADU.

Some details of pre-approved plans can guide retroactive permit corrections on unpermitted units that need layout or code updates.

Parking, Setbacks, Multi-Unit Rules, and Tax or Rent Items for ADUs

Key site rules still apply during legalization:

• Setbacks: Most detached ADUs can sit 4 feet from side and rear property lines
• Parking: No parking is required within a half-mile of transit or when you convert a garage or carport that sits within the existing footprint
• Multi-unit lots: Many multifamily zones can host multiple dwelling units, such as two detached ADUs behind an apartment building
• Rent and tax items: New ADUs often qualify for rent control exemptions and may trigger property tax adjustments based on added value

For current standards, review LADBS ADU resources and California HCD guidance.

Zoning and Site Checks Before Applying for an ADU Building Permit

Confirm Your Zone With ZIMAS and LADBS

Start with zoning. Use ZIMAS to find your zone, overlays, and any special conditions. R1, R2, RD, and most multifamily zones support accessory dwelling units.

Check for hillside or coastal overlays, historic districts, and fire severity zones. LADBS can confirm rules for your parcel and note any extra reviews that may apply to your ADU in Los Angeles.

Setbacks, Height, and Lot Coverage Basics for ADUs

Most detached ADUs follow 4-foot side and rear setbacks. Many one-story ADUs top out near 16 feet in height, with options for taller forms based on roof type, lot conditions, or when above garages.

Lot coverage and floor area rules vary by zone, though state law protects a minimum size on most residential lots. During legalization, the city will look at how your unpermitted unit sits on the site, so confirming these limits early can shape the correction plan.

Parking Near Transit and ADU Garage Conversions

If your property sits within a half-mile of transit, the off-street parking requirement for an ADU in Los Angeles is often waived. Garage conversions normally waive replacement parking for the main house if the conversion is within the existing footprint.

Confirm your location with ZIMAS and Metro maps to avoid delays during plan check.

Step 1: Free Site Visit and Initial Inspection

LADU Feasibility Walk-Through and Code Triage

LADU starts with a free site visit focused on feasibility, safety, and code gaps.

An architect inspects the structure for signs of settlement or framing changes, checks fire separation at shared walls, reviews electrical panel size and circuit protection, scans visible plumbing lines for leaks or improper slopes, and confirms life-safety features such as exits and egress.

The goal is to map a clean path to compliance for your unpermitted ADU while keeping useful existing work.

Collect Records and As-Built Documentation

Good documentation speeds a retroactive permit. We help you gather:

• Any prior permits, LADBS violation notices, or orders to comply
• Photos and measurements of current conditions
• Utility data, such as panel size, gas meter capacity, and sewer cleanout locations
• Simple as-built plans that show walls, openings, fixtures, and equipment

Clear as-built documentation lets our team draw accurate plans and reduce back-and-forth hassles during plan check.

Safety Features To Document

Inspectors will check:

• Exits, door width, and egress windows sized for the sleeping area
• Smoke and CO alarms in the right locations
• Stair geometry and guards that meet code
• Gas venting, clearances for appliances, and combustion air
• GFCI and AFCI protection at required circuits
• Plumbing vents, trap arms, and cleanouts that match code standards

Step 2: Plan a Path To Legal ADU Compliance and Upgrades

Architectural Plans and ADU Design Tailored to Code

Legalizing an unpermitted ADU requires a permit-ready plan set. LADU prepares architectural drawings that capture current conditions and the upgrades needed for compliance.

Plans may include a revised floor plan for safer circulation, properly sized bedrooms, and accessible exits; a site plan with setbacks and utility runs; elevations; sections; and energy documentation under Title 24.

ADU Structural, Electrical, and Plumbing Scope

Our team maps a full correction scope so plan check is clean and field work is predictable:

• Structural: Verify load paths, add shear walls where needed, upgrade anchors, and correct framing changes from past work
• Electrical: Right-size the service or subpanel, label circuits, add GFCI and AFCI, and add dedicated circuits for appliances
• Plumbing: Correct DWV slopes, size supply lines, add shutoffs and cleanouts, and verify water heater TPR discharge

Fire Separation and Energy Upgrades

Common corrections for garage conversions include 1-hour fire-rated walls and ceilings between the ADU and any remaining garage or house, fire blocking at concealed spaces, and protected openings.

Life-safety items include smoke and CO detectors and address numbers visible from the street. Energy upgrades can include insulation at walls and ceilings, high-performance windows, and air sealing to meet Title 24 targets.

Larger dwelling units may require sprinklers, depending on size or local amendments. LADU confirms requirements during plan check so your legalization plan is complete.

Step 3: Submit Your Retroactive Permit Package to LADBS

Building, Mechanical, Electrical, and Plumbing Permits

Legalizing an unpermitted ADU can involve several permit types:

• Building permit: Covers structural work, layout changes, insulation, windows, and finishes
• Electrical permit: New circuits, panel upgrades, outlets, lighting, and protection devices
• Plumbing permit: DWV adjustments, water lines, fixtures, and water heater work
• Mechanical permit: Ventilation, fans, mini-splits, and duct work

Some projects add a grading permit for hillside sites, a sewer permit for new laterals, or a separate electrical service upgrade if the main panel cannot support the load.

LADU scopes these items at the start and then packages them with your ADU building permit application.

Your ePlanLA Submittal, Plan Check, and Fees

Los Angeles uses ePlanLA for online submittals. We upload drawings, forms, and calculations, pay initial fees, and start the 60-day ministerial review. Plan check comments arrive as a correction list. Our team issues revisions and resubmits until all items clear.

Fees are based on project size and scope, with separate line items for building, plan check, and trade permits. LADU tracks the review clock and coordinates responses so your file keeps moving.

Pre-Approved Plans vs. Custom Plans

Pre-approved ADU plans can speed a new ADU on a clean site. For unpermitted ADUs, a custom plan is often the right path since existing conditions rarely match a standard layout.

Step 4: ADU Corrections, Construction, and Inspections

Responding to ADU Plan Check Corrections

Plan check is a dialogue. The city issues a list of corrections. We update drawings, add details, and clarify scope.

If a zoning or building item needs a field fix, we can connect you with our ADU construction partners so revisions line up with what inspectors expect. This reduces extra rounds and helps you legalize unpermitted ADUs with fewer delays.

Field Inspections and Sequencing

Once permits are issued, work begins. The inspector visits at key milestones:

• Rough-in inspections for framing, electrical, and plumbing
• Insulation inspection and energy items
• Lath or shear inspections if required by scope
• Drywall, finishes, and device installation
• Final trade inspections and LADBS final

LADU schedules visits in a logical sequence, coordinates responses, and keeps documentation tight so each inspection passes cleanly.

Certificate of Occupancy and ADU Legalization

After the final inspection, LADBS closes the retroactive permit. Your unpermitted ADU becomes a legal ADU. You receive final paperwork and can move forward with renting the ADU, using it for family, or refinancing with confidence.

Costs, ADU Permit Fees, and Financing Options

ADU Permit and Plan Check Fees

Fees vary by size and scope, though most Los Angeles projects follow a similar pattern:

• Building and plan check fees: Commonly in the range of $2,000 to $8,000 for modest units, higher for complex scopes
• Trade permits: Electrical, plumbing, and mechanical combined can add $1,000 to $4,000 on many projects
• Impact fees: State law waives some local impact fees for ADUs under 750 square feet, though school fees or utility fees can still apply based on size

LADU prepares a fee estimate once the plan set and scope are defined. We handle payments through the portal and keep receipts organized for your records.

Typical ADU Upgrade Costs During Legalization

Common upgrades for an unpermitted ADU include:

• Electrical panel upgrades: New service or subpanel, breakers, and labeling
• Fire separation: One-hour assemblies at shared walls or garage conversions
• Insulation and windows: Title 24 energy package with air sealing
• Plumbing reroutes: DWV corrections, venting, and cleanouts
• Drywall and finishes: After rough-in corrections and insulation inspections

Fixed Pricing and Financing

LADU's model is built on transparency with fixed pricing for our ADU design services and ADU permit assistance. Financing options are available for legalizing an unpermitted unit, so you can spread costs across a timeline that fits your plans.

Timelines and How To Speed up ADU Permits

Typical Schedule

Most projects follow a simple path:

• Assessment and plans: 1 to 3 weeks for site visit, as-builts, and drawings
• Plan check: Up to 60 days for ministerial review with one or two correction rounds
• Corrections and inspections: 1 to 3 months based on scope and access

Project size, zone overlays, and utility upgrades influence the exact pace, but the 60-day review window sets a clear cadence for your legalization process.

How To Save Time

Speed comes from preparation and quick responses:

• Gather records early: Old permits, violation notices, and utility data
• Respond to corrections fast: Revisions returned within a few days keep the file moving
• Use pre-approved details where they fit: Standard notes can reduce questions
• Coordinate utilities early: Panel upgrades or sewer work can run in parallel with plan check

What Slows Permits and How LADU Mitigates

Common delays include limited access for inspections, missing records, utility lead times, and complex zones with overlays. LADU plans around these risks.

Our one-team flow keeps design, permitting, and arranged construction in sync so idle time is limited and your unpermitted ADU stays on track to legalize.

Common Code Issues in Illegal ADUs

Exits, Egress, and Alarms

Inspectors focus on life-safety first.

• Doors need clear width and landing space
• Bedrooms need egress windows sized for escape and rescue
• Stairs need consistent risers and handrails
• Smoke and CO alarms must be installed in sleeping areas and outside bedrooms
• Address numbers must be visible from the street so first responders can find the unit

Electrical and Plumbing Corrections

Many unpermitted units show panel overloading, missing GFCI and AFCI protection, or unlabeled circuits. Bonding and grounding must match current code.

On the plumbing side, common issues include undersized vents, flat or back-pitched drains, missing cleanouts, and water heater TPR discharge lines that do not terminate safely. These items are straightforward once a plan is in place and parts are on site.

Fire, Structure, and Energy

Garage conversions often require 1-hour assemblies and proper separation from the house. Structural items such as sill plates and anchor bolts must be present and protected from moisture.

Emergency shutoffs for gas and power must be accessible. Title 24 energy items such as insulation levels, window performance, and duct sealing raise comfort and safety, and they help the unit pass inspection the first time.

Benefits After You Legalize Your ADU

A fully legal ADU provides several key benefits that are often forfeited when units don't meet code requirements.

Rental Income and Rent Rules

With a legal ADU, you can advertise with confidence and qualify for rent rules that favor new units under current codes. Many new ADUs are exempt from rent control programs that apply to older buildings.

Property Value and Refinance

Permits and inspections create a clear record for appraisers and lenders. A legal ADU adds living space with defined value. Clean disclosures reduce friction during sale or refinancing and can open loan programs geared toward accessory dwelling units.

Peace of Mind and Safety

Legalizing an unpermitted ADU protects the homeowner and the tenant. A final permit means the unit meets current building codes, shutoffs and alarms work, and systems have been tested. You reduce risk and gain a reliable path for future maintenance and upgrades.

Why LADU Is the Fastest Path to a Legal ADU

One Team. One Contract. One Goal.

LADU manages the entire flow. Our in-house team leads ADU design and ADU building permits and then can arrange any needed construction through trusted, licensed partners.

One contract, one coordinated schedule, one point of contact. That clarity helps legalize unpermitted ADUs with fewer surprises.

Architecture-Led Code Expertise

Our architect-led approach anticipates zoning and building codes from day one. That means smarter layouts, fewer plan check rounds, and correction lists that match a ready field strategy. It is a direct way to legalize your ADU without spinning cycles.

Fixed Pricing. No Surprises.

We charge flat fees for plans and permitting and define the permit scope.

ADUs Designed Better. Built Smarter.

Ready To Legalize Your Unpermitted ADU?

You now know how to permit an unpermitted ADU in Los Angeles: verify your zone, book an assessment, develop a permit-ready plan set, submit to LADBS, complete corrections, schedule construction and inspections, and secure final approval.

The advantages in 2025 include 60-day ministerial reviews, pre-approved plans, and Assembly Bill 2533 (AB 2533) that supports a retroactive permit that can reduce a fine when basic safety is met.

That means a safer, legal ADU with documented compliance and a smoother path for garage conversions and other unpermitted ADUs.

At LADU, we legalize an unpermitted ADU with fewer detours and cleaner inspections. Ready to legalize your ADU and protect your investment with a legal ADU that passes inspection and meets compliance?

Schedule your free site assessment or call (213) 855-3334 today to turn an unpermitted dwelling unit into a permitted, code-compliant ADU in Los Angeles with a plan that fits your timeline and budget.

Design + Permitting + Build = LADU