How to Extend Your Garage

Co-authored by James Mansfield and Janice Tieperman

Last Updated: September 24, 2022 References

Is your garage a bit too cramped for comfort, or are you looking to repurpose some unused space? Garage extensions are definitely a big undertaking, but the end results are very rewarding. If you aren’t sure where to start, check out this guide—it tackles several frequently-asked questions about garage extensions, so you can put your best foot forward during your future home improvements!

Question 1 of 8:

How can I extend my one-car garage?

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Lengthen your garage to create a larger workspace. Does your garage tend to double as a home workshop? When you lengthen your garage, you create a lot more room for your tools and equipment. This type of extension can also provide more storage space, or help convert your garage into another living space.^{[1]
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- For instance, you might lengthen your garage to make room for a home gym.
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Widen your garage to fit more cars. Parking space is essential to any home, especially if you’re getting a new car. Transform your one-car garage into a two-car garage, or widen your garage slightly to give your car a little more room.^{[2]
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- A small extension can help if you store bikes and other outdoor equipment in your garage.
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Raise your garage height to fit bigger vehicles. A typical garage is great for basic vehicles, like sedans and SUVs, but likely won’t be tall enough for a trailer or RV. A taller garage can also fit a car lift, which makes working on your vehicles much easier.^{[3]
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- Garage height extensions are great if you don’t have enough space to extend in other directions.

Question 2 of 8:

Can I build an addition on top of my garage?

You can, but it requires a lot of construction and planning. First, you’ll need to hire an engineer to inspect your current garage—they’ll let you know if the frame and foundation can support an extra extension. Then, ask a contractor to inspect and reinforce the garage’s foundation if needed. At this point, hire building professionals to complete the renovations, who can make sure the addition is up to code.^{[4]
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- For instance, your base garage needs a ⁵⁄₈ in (1.6 cm) layer of drywall added along the walls and ceilings when an addition gets installed.

Question 3 of 8:

Can I turn my garage into extra living space?

Yes, you can definitely transform your garage into more living space. You might turn your garage into a studio apartment, or convert it into a home gym. Other people turn their garages into home offices, playrooms, or kitchen extensions.^{[5]
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- You could also turn your garage into a crafting space or laid-back rec area.

Question 4 of 8:

Do I need a permit to extend my garage?

You’ll probably need a permit, but it depends on where you live. Meet with a local government employee to see what specific permits you’ll need—different cities, states, provinces, and countries each have unique zoning requirements. Schedule an appointment at your local government office; when you meet, let them know what kind of project you’re planning. They’ll tell you what type of zoning or building permits you’ll need, and give you specific applications to fill out.
- In Prince William County, Virginia, you need a building permit and zoning approval to extend your garage.

Question 5 of 8:

How close to my property line can I build an extension?

Ask your county or local government for specifics. Zoning requirements aren’t universal, and your project requirements will definitely depend on where you live. Stop by your local government office—an employee there can let you know what is and isn’t allowed.
- In Fremont, California, you can extend your home up to 10 ft (3.0 m) from the back property line, as long as your expansion doesn’t take up more than 30% of the backyard.^{[6]
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Question 6 of 8:

Can I extend my garage by myself?

You technically can, but it’s not a great idea. Unless you have a lot of contracting experience, you’re better off hiring a professional. Garage extensions require a lot of construction and engineering expertise. To be safe, hire professional contractors to get the job done.^{[7]
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Question 7 of 8:

How much does a garage extension cost?

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The average garage extension costs over $12,000. When you break it down, garage extension projects are a combination of materials and labor. Certain materials, like brick and metal, are significantly more expensive than other building materials, like wood. Additionally, bigger projects, like converting a one-car garage into a two-car garage take more time to complete, and cost more than a smaller add-on.^{[8]
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- The pricing will ultimately depend on the contractor you work with. Scout out different quotes online before committing to a specific builder!
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The extension will cost more if you hire construction specialists. If you’re expanding and converting your garage into a different space, you may need extra professionals to finish the job, like carpenters and electricians. For large-scale jobs, like an addition, you might also hire an architect or designer to draw out the extension plans.^{[9]
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Question 8 of 8:

How long does it take to build a garage?

It usually takes between 1-2 weeks to build a garage. Ultimately, the timeline depends on the extension you’re getting done, as well as the materials you’re using. Before construction really gets underway, to ask your contractor for an estimate.^{[10]
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- For example, it takes a lot longer to build with brick than concrete.

Expert Q&A

Question

Should I insulate an unheated garage?

James Mansfield
Construction & Design Specialist
James Mansfield is a Construction and Design Specialist and the CEO of WestVillage General Contracting, a high-end and luxury design/build firm in New York City. James specializes in apartment, bathroom, and kitchen remodeling as well as fine cabinetry, lighting, paint, and wallpaper. James has developed a proprietary system of construction called the Luxury Build Method that hinges on a skilled team, respected partnerships, and clear, transparent communication. WestVillage GC has completed more than 500 commercial and residential projects in New York with designers such as David Scott Interiors and Fox Nahem, Kelly Behun. WestVillage GC is also a preferred contractor for Related buildings including Hudson Yards.

James Mansfield

Construction & Design Specialist

Expert Answer

That depends on where you live—if you live somewhere that gets really cold, yes, you probably should. It will cost a little more in the short term, but insulation and sheetrock will help the garage trap as much heat from the house as possible. If you don't insulate it, your heating bill over the next 4-5 years might outrun what it would have cost you to finish the walls in the first place.