Can You Build an ADU on Top of a Garage?

April 15, 2025

Some homeowners want to build an ADU, but don’t have space on their lot due to an existing detached garage. The good news is that an unused garage space can easily be converted to a secondary living space! Whether you choose to add a story and build an ADU on top of your garage, convert existing space into an ADU, or demolish and start fresh — a garage conversion might be the right choice for you. 

Learn more about how you can build an accessory dwelling unit on top of an existing garage.  

Benefits of a Garage Conversion

Garage conversions offer many the same benefits as a detached ADU. However, there are some distinctions that may make them a better choice for your lifestyle.  

More living space 

A garage conversion offers increased living space just like any other ADU. Whether you opt to convert your garage space into an apartment or build on top, you’ll reap the benefits of more space, tailored to your needs.  

Whether you need more space to provide a private sanctuary for aging family members, a retreat for guests, or a private room for your teenagers, a garage conversion provides more space on your property.   

Increased property value 

Any form of ADU on your property has the potential to increase your property value. Generally speaking, adding a secondary living space can increase your property value by 35%

In addition, a garage conversion can turn unused storage space into an income stream. Aside from increasing your property value should you decide to sell, a garage conversion can be a long-term rental, allowing you to capture more income or offset your mortgage. 

No change to your lot’s footprint 

One benefit unique to garage conversions is that it doesn’t require a change to the layout of buildings on your property. If you don’t have a lot of additional space on your property, take pride in your well-manicured yard, or simply don’t want to add another structure, a garage conversion may be the best choice! 

Different Types of Garage Conversions 

When considering a garage conversion, think about your goals and needs before browsing options. Do you want to make use of your existing structure or would you prefer a brand-new space? Either way, you have options for building an ADU. 

Full Conversions

If you truly don’t use the storage space in your garage, you can make use of the space by converting it into an ADU. This is a good option if you are working with an ADU builder or contractor that can rework your existing layout into a customized space. Keep in mind that this may  be more expensive due to demolition, reconfiguring existing walls, and adding utilities.   

Add-a-Story 

A great option is you don’t want to lose parking space or storage is a single-bedroom ADU on top of your garage. Sometimes referred to as FROG, meaning “front room over garage,” these additions provide the best of both worlds — storage and living space. Plus, adding a story to an existing space is an efficient and cost-effective way to add to your living space. 

You can view our garage conversion floor plan here.

Can Every Garage Be Converted into an ADU? 

Not all garages are good candidates for ADUs to be added on top. If your garage is more than 30 years old, it’s likely not a great candidate due to structural integrity issues that come along with wear and tear. In addition, a newer garage that hasn’t been well-maintained and had stability issues also wouldn’t be a good choice to build on top of. 

In those cases, you may still be able to replace your garage with a new ADU if the expanded living space is a high priority for your family. 

Start Your Garage Conversion Today

SmartSpaces specializes in building ADUs, tailored to your lifestyle needs and requirements. We offer fully-customizable floorplans that can accommodate accessibility requirements, multi-generational living, or hobby and entertainment spaces. 

If you are specifically interested in a garage, learn more about our add-a-story floor plan and browse other models. If you are ready to move forward — contact us for a free consultation.  

Rick Starkey of SmartSpaces ADUs

Rich, Founder of Smart Spaces ADUs

Thanks to his passion for his community, Rich founded Smart Spaces ADUs to build affordable, accessible homes that cater to unique living experiences. SmartSpaces ADUs is Eastern Atlanta’s premier provider of ADUs, garage conversions and tiny homes.

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