Building an ADU Above Your Garage: Here’s the (Second) Story

Homeowners might know that the California state government has relaxed the rules and restrictions around building an ADU (Accessory Dwelling Unit or Additional Dwelling Unit) in Los Angeles & throughout Southern California. This is exciting, as you can now consider building a secondary housing unit with independent living facilities on a residential lot. 

Here at GreatBuildz, a free service that connects homeowners in Los Angeles, Orange, Ventura and San Diego Counties with reliable ADU contractors, we speak to homeowners every day about planning their desired ADU project and budgeting for ADU construction costs – here are some ideas & tips to get you started.

This ADU is an additional living unit on a property. An ADU above the garage can be a perfect place to add space while leaving the garage itself to park and store your vehicles.  

However, before you run off to meet contractors, here are some things you need to know about building an ADU on top of the garage.

Benefits of an ADU Above the Garage

A primary benefit of an ADU over a garage is as an investment. There are two ways you can earn from your ADU: 

ADU above your garage Los Angeles

Photo Credit: Durham Construction

  1. Rental Unit to Earn Passive Income

You can design an ADU with an entrance, kitchen, bathroom, and bedroom, and then rent it out to short-term or long-term tenants.

  1. Increased Property Value

According to Forbes, more homeowners are willing to pay for properties with ADUs attached since they realize the benefits of using them for living arrangements or investment values.

In general, building an ADU above the garage might cost a little more, but the return on investment (ROI) should make that cost worthwhile.

Estimated Cost of Building an ADU Over Garage

According to Kol Peterson at, the building cost of an ADU above garage averages around $200,000

This estimation is from homeowners who built an ADU recently in Los Angeles and Southern California. The cost of construction for the same structure can vary greatly depending on the contractor, as well as what the current cost of labor and materials are in a given region.

Like any building job, the importance of getting good and experienced builders factors greatly into the prices.

Building an ADU Above Your Garage: Here's the (Second) Story 1

The structural foundations of garages vary. However, the costs of building an ADU over a garage differ too. Some buildings require more labor or materials, and the complexity and amount of work required vary from one garage to another.

 These things may make the project cost more than expected:

  • Refinishing the entire exterior of the structure.
  • The attached garage requires alignment with the second floor.
  • Utilities are costlier to install.
  • The addition of stairs and a new roof.
  • Older garages often require more expense 
  • Reinforcing old foundations to support the 2nd floor

The property’s age has a significant influence on the final bill. However, if you rent out the unit or sell your house in the future, the return on investment (ROI) might be worth it.

Pro tip: You can save costs on the construction of your second-story ADU above a garage by considering a simple design. If you stack your ADU living space directly above the four corners of your existing garage, that is likely to save you costs on framing, structural elements, and other costs. If your area allows it, planning for an outdoor stairway will also save costs rather than an interior staircase, as you won’t need to add interior space to the first/garage level floor.

Renting Out Your ADU

There are some guidelines that you need to take note of when renting out an ADU, but generally, it works just like a typical rental accommodation. You will need to decide the lease terms and the rental amount. You can check for more information on L.A.’s rental laws for ADUs here. 

The Uses of an ADU Over a Garage

Build an ADU over your garage

Photo Credit: Bau10 & Paul Vu

Another reason to consider building an ADU is to increase your living space. Here are some uses for an ADU: 

1. A Space for Seniors or Guests

Building an ADU for grandparents or other elderly relatives allows the family to care for them closer to home while also enabling them to live independently. An ADU can also act as a guest room during holidays.

2. The Ultimate Home Office or Workout Space

Many people work from home, and an ADU can be a perfect space for a home office. Away from the noise of the main house, this can also be an excellent place to put a study room or workout space.

3. A Room for Adult Children

With rental prices increasing, it may be a good idea to add an ADU for adult children. They can stay in the extra space and still maintain a high degree of independence. 

Ideas & Tips For an ADU Above My Garage

Now that you know the benefits of building a 2nd story ADU, here are some tips to keep in mind when doing so:

1. Add Light With Large Windows and Layered Lighting

Building an ADU Above Your Garage: Here's the (Second) Story 2

Natural light makes a small space feel more spacious and helps improve the mood. Glass panels and skylights are both excellent ways to do this, and high clerestory windows will only allow sunlight in while maintaining privacy, which is especially good for bedrooms or bathrooms.

Layered lighting can also help create a bright, airy space. Think about all the sources of light that you could incorporate in addition to natural light. Recessed can lighting creates an elegant look that lights up large spaces and can be complemented with pendant fixtures for areas that need more light, like a dining room or bedroom.

2. Choose Colors That Make the Space Look Bigger

White is often used to paint a second story ADU because it complements almost every color on the color wheel and works well in most color schemes. White reflects light, brightening the room and making it appear larger. However, other brighter color schemes will also do the trick of making the space bigger.

3. Optimize Storage to Free Up Livable Space

Design built-in shelves and cabinets into your accessory dwelling plan whenever possible. Storable and convertible furniture will also help save space — from storage ottomans to foldaway beds. 

The Process To Build an ADU Over Your Garage

Below are four steps to building your second story ADU.

1. Design the ADU plans

Design ADU above garage plans

Hire a professional architect. An architect will help you determine what you need and work with you to develop your 2nd story ADU plans.

2. Get a Pre-approved Loan

After finishing your ADU plans, apply for a pre-approved loan with your bank or other financial institution.

3. Get the Design Approved by the Los Angeles Building Department

Apply to the building department to get your blueprint approved. If your blueprint meets regulations, it will be approved. After that, you can start the application for a construction permit.

4. Find a reliable ADU Contractor

You will need to check with your contractor on the duration of the work and the progress payments required for the ADU project. The timeline for processing the project paperwork, loan, and project construction are about six to nine months. Here are some tips to help you find an ADU contractor


When it comes to adding an ADU to your property, you shouldn’t have to go it alone – GreatBuildz can help simplify your renovation experience.



GreatBuildz is a free service that connects homeowners in Los Angeles, Orange County, Ventura or San Diego with reliable, thoroughly screened general contractors and provides project support from start to finish. Call now (818.317.3567) to chat with a real person about your next remodel project or visit our website for more information:

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