Garage Conversions, Detached ADUs and Attached Units
Start by saying whether the garage is attached or separate and what you want the finished space to do. A few details are enough for the first enquiry; drawings and measurements can be added when available.
Explore Garage Conversion ADUs in Los Angeles, compare the cost guide or get a quote when you are ready.
Choose the Right ADU Construction Project
Detached ADU
A detached ADU is a different building. Its price must cover the foundation, frame, roof, exterior walls, heating, cooling, electrical and plumbing work. Backyard access and the distance to utility connections can matter as much as square footage.
Garage conversion
A garage conversion ADU reuses an existing building only when it is suitable for living space. The slab, frame, moisture, ceiling height, fire protection and utilities all need to be checked. A garage that looks easy to convert may need major rebuilding.
Attached ADU or JADU
An attached ADU or JADU may use an addition or space inside the home. These options have different size, location and occupancy rules. Consider privacy, noise and the amount of electrical, water and sewer service available.
Pre-Approved ADU Plans and Property Requirements
LADBS Standard Plan Program guidance (checked October 13, 2026) explains that an approved design can reduce repeated plan review. LADBS still checks the property’s zoning and foundation needs, and it warns that an approved plan may not work for every site condition. A catalog image cannot settle those questions. Confirm the design’s current approval and property requirements with LADBS using the project address.
Check the current approval status of the exact design before paying for plans or asking a builder to price around them.
Compare standard plans, prefab units and custom designs by total project cost and property fit, not by the price of the drawings alone.
What Does an ADU Cost in Los Angeles?
LADU publishes $150,000–$400,000-plus for Los Angeles ADUs generally. Construction Consulting Services lists $200,000–$480,000 for detached units of 700–1,200 square feet. These are the companies’ different planning examples, not a local average or your project quote. Hillsides, long utility runs and tight access can raise the price. So can electrical upgrades, drainage and custom finishes.
The Los Angeles ADU cost guide separates the items below.
- early site checks, survey and design;
- structural and energy documents;
- plan check, permits and agency charges;
- demolition, grading, foundation and access;
- structure, envelope and interiors;
- electrical, water, sewer, gas and communications;
- appliances, fixtures and allowances;
- landscape and property repairs after the work; and
- extra budget for surprises and owner-supplied items.
ADU Utility Connections and Scheduling
LADWP lists 100 calendar days for typical small water-service work. This is only a guide. Permits, project needs and crew availability can change it. LADWP also says a residential meter-spot visit is usually arranged within 5 to 15 business days.
Those timeframes cover only part of the utility process. They are not complete ADU schedules. Find the likely utility work before accepting a promised start or finish date. The utilities and site-work guide explains what each quote should include.
Comparing Los Angeles ADU Builders
California’s Contractors State License Board advises owners to get at least 3 written quotes. Each company should price the same drawings, materials and work. CSLB also provides a public license check. It says a home-improvement contract should describe the work, payments, permits and timing.
Use the ADU builder comparison to make sure every quote includes the same work. A low total may not be a bargain if it leaves out plans, utilities, repairs or important finishes.
Local ADU Construction and Permit Guides
Los Angeles County includes the City of Los Angeles, many other cities and unincorporated communities. They do not share one permit office. The service-area guide will help you choose the correct location page.
Company availability is checked after you describe the property and project. No page on this site promises service at every address.
Request an ADU Construction Quote
Use your name, email, city or ZIP and a short project description. Mention a backyard unit, garage conversion or attached ADU if you have a preference; it is fine to be considering the options.
Get a Quote before you have a survey or finished plans. Size, access, utility details and existing documents can be discussed with a provider later. An enquiry does not approve the parcel or set the final price.
Frequently asked questions
Is this website an ADU contractor?
No. The site publishes independent planning details and may make introductions. Each company is responsible for its own credentials, plans, permits, contract and work.
Can a pre-approved plan be used on any Los Angeles property?
No. LADBS and other local programs still require a site review. Jurisdiction, zoning, foundation, access, fire, utility and other parcel conditions can affect whether a plan works.
Can I get an exact ADU price from photos?
No. Photos can help with an early discussion. But they cannot prove that the project is allowed. They also cannot show hidden conditions, complete utility work or everything a building price should include.
Should I choose a builder before checking the property?
You can interview companies early. Do not compare fixed prices until the property facts, design basis, site work, utilities, allowances and exclusions are clear.