How to Convert a Garage into an ADU

ADU garage conversions are one of the most cost-effective ways to add an accessory dwelling unit to your property. Why? Since a garage is an existing structure, you can potentially save thousands of dollars compared to the cost of a new stick-built ADU. Furthermore, the State of California has passed laws that make it much easier to convert existing garages into ADUs. 

Types of ADU Garage Conversions

Generally, residential properties have one of two types of garages: attached or detached. Depending on the type of garage you’re dealing with, there are certain things to know about your ADU garage conversion. 

Detached Garages

Detached garages are an ideal candidate for ADU potential, due to the separation from the unit and primary dwelling. 

One of the biggest concerns I hear from people interested in ADUs, is the potential lack of privacy between them and their ADU tenant. With a detached ADU, there is more opportunity to create a clear separation between the main home and the unit. 

Depending on how the backyard is laid out, you can also potentially create some backyard space for the ADU. Outdoor space is an amenity that certainly makes a unit more attractive to renters thus, allowing you to charge higher rent.

Attached Garages

Don’t have a detached garage? No worries! Attached garages are great too for ADU conversions. There are creative ways to turn an attached garage into a private ADU.

One of the biggest advantages of attached garage ADUs is the potential ease of hooking up utilities such as electricity and plumbing. Since the garage is attached, the plumbing and wiring can be extended from the main house versus being stretched to a detached structure. This means you can potentially save on construction costs. 

Above Garage ADUs: Pros and Cons

One of the greatest benefits of an above garage ADU is the ability to keep your garage space.Also, depending on where your property is located, an above garage ADU can take advantage of scenic views. This type of ADU may be best suited for a detached garage, but they are also common for attached garages as well. 

Above garage ADUs may sound like a great idea, but there are certainly a few disadvantages. The main factor to consider is cost. Building above a garage will add an estimated $30K. Why the added cost? Since a garage is not intentionally designed to support a second floor, the foundation and walls must be structurally reinforced in order to carry the weight of a unit above.

It’s an expensive project to pursue, however, it may be worth the potential return on investment. For example, if you’re located near the beach, an above garage ADU that has ocean views would be a lucrative opportunity where you can charge higher rents.

In short, there are certainly advantages and disadvantages to building an above garage ADU. Here’s a quick summary of the pros and cons of above garage ADUs.  

Pros:

Cons:

• Expensive
• Longer construction times

How much does it cost to convert a garage into an ADU?

Now that you know all about ADU garage conversions, you must be wondering “How much does it cost?”

With design and construction costs being so highly varied, it is difficult to estimate the cost of an ADU garage conversion. Furthermore, there are many factors that affect the cost of your ADU conversion, such as:

• Zoning rules and regulations
• Condition of the garage
• Utility hookups
• Foundation issues
• Lot issues
• Design 
• Choice of materials and fixtures

From my experience consulting homeowners throughout San Diego, I’ve typically seen rough costs ranging from $60K to $100K for an ADU garage conversion. Above garage ADUs may cost roughly $150K or more. 

These numbers might seem steep, but building an ADU is an investment you’re making on your property. It’s an investment that can potentially give you both short-term benefits from monthly rental income and long-term benefits from increased property value. 

5 Design Ideas to Spruce Up your Garage ADU

Garage ADU conversions are certainly one of the most popular ways homeowners are creating ADUs. There are plenty of garage ADU designs to get inspired by so that’s why I’ve rounded up a few of my favorite designs to inspire your project. 

1. Exposed Beams

Exposed beams are one of my favorite elements in a garage ADU. By exposing the ceiling, you’re able to create high ceilings that make a smaller space feel much larger. The exposed wooden beams that may be hidden above your garage ceiling offer a nice architectural design feature that draws the eye up, creating a more open space and feel.

2. Indoor Outdoor Living

Indoor outdoor living is a highly desired design concept, especially in Southern California where the weather is amazing throughout most of the year. 

Since garage ADUs are typically on the smaller size, an indoor/outdoor concept is a great way to create more livable square footage outside of the unit itself. Providing outdoor living space is also a great amenity to have that will allow you to charge higher rents as well. 

3. Open Concept

Speaking of open spaces, open design concepts are a must for every ADU garage conversion. Since garage ADUs are typically smaller than a conventional home or apartment, an open concept will really help to make the space feel a lot larger than it really is.  

4. Natural Light

Having plenty of windows will allow natural light to flow into your ADU to brighten up the space. Concerned about privacy? Creative design elements such as clearstory windows and skylights can help achieve this goal while maintaining maximum privacy. 

5. Storage

As with any living space, storage is highly important – especially for ADUs. Given the smaller space, it is critical to create plenty of hidden storage spaces. This is where a designer with ADU experience will really come in handy. They’ll be able to craft creative storage solutions that will integrate seamlessly into your ADU design. 

Find the perfect home for your ADU garage conversion

In the market for an ADU-able home? One of my top tips is to find a home with a garage that is in good condition. You can also check out my guide on how to identify ADU homes with maximum potential. 

As San Diego’s ADU agent, I can help you find the best ADU-able homes on the market. With so many factors to consider, you can feel rest-assured when working with me to find your dream home that will give you the best return on your investment.