Can You Extend Your Garage and Make it Bigger?

Perhaps your car is too long to fit inside the garage, or you own two cars but have a single car garage, or you simply want extra storage space in your garage. Whatever the reason, extending your smaller garage into a bigger one can certainly be useful in many ways. But is it possible to extend your existing garage? I researched this topic, and I’m going to share everything I learned with you.

Yes, it’s possible to extend your garage. You can extend the garage’s length or depth with a bump-out extension from the back or front or extend the width of the garage from the side. However, you may need a building permit, an HOA approval, and have to follow your local zoning guidelines.

I’ll share with you all of the factors you need to consider before starting this garage extension project. After that, we’ll discuss the different ways you can extend your garage to find an option that will work best for you. Let’s get into it.

Factors to Consider Before Extending Your Garage

A lot of things will come into play when you want to extend your garage. That’s because making structural changes to your home can be very simple or complicated, depending on your situation. So, you must have the right knowledge before you get started. So what are some of the things to consider?

Available Lot Size

The first thing that should come into your mind is your plot size and its available space.

Do you have enough free space on the side of your garage? What about the back or front of the garage? How many feet of extra garage space will you get when you extend it? Will it be enough to park your vehicle(s)?

These are some of the questions you should ask before you even consider the extension project. Go outside and check the available plot size around your garage. Take measurements of the available plot size on the sides, front or back of the garage, and compare it to the extra square feet of space you want in the garage. 

To properly know the available plot size you can use, you need to be aware of your local zoning guidelines. What do I mean by this?

Most cities require you to have a permanent structure on your plot a few feets away from your property line. For instance, the Brooklyn Ohio Zoning Guide requires you to build your garage at least 3 feet away from the rear and side property lines. Most city codes require at least 5′ away from the property line. This will certainly affect how wide or deep you can extend the garage. To know these values, I recommend you check in with your local building department.

The space you have on your plot will determine how you can extend the garage. We will discuss the different ways you can extend it later in the article.


The building department of your city has the responsibility to make sure every building and structure in the area is safe to be in and complies with the area’s building codes. 

For this reason, before you can extend the size of your garage, you’ll need a permit. This is considered a major renovation which has to be overseen by the building department. 

Depending on how complex the extension may be, the department may require you to submit a site plan. This will include all the structural changes you’ll like to make, the choice of garage flooring after extension, the roofing, and more. Some building code authorities may even require drawings of your proposed design.

Once you hire a contractor, they will come and inspect your garage and property. And based on their experience, they will know the best way to go about the extension so that it’s safe and complies with building codes. 

Once your contractor is done with the inspection, he will develop a site plan and architectural drawings for the garage extension, when required, and then submit them to the building department for approval.


Cost is one of the most important things to consider when you’re planning to extend the garage’s size. Garage extension can be expensive, depending on the structural changes that have to be made to your home.

You may need to lay a new foundation and concrete slab for the garage, install a new roof or even install a new garage door. All of these changes will depend on your situation and how big you want to extend the garage.

The building contractor may also charge higher than their usual fee. That is because garage renovations can come with many complications compared to building from scratch. It can take a lot of effort to extend the size of a garage without causing any damage to the rest of the house.

You will also have to pay a fee for the building permit. The amount depends on how your local building department calculates it.  

According to HomeAdvisor, garage extension costs as much as building a new attached garage. It can cost between $40 and $70 per square feet. And to expand your garage from a single car garage into a 2-car garage can cost $12,000 to $21000

The Different Ways to Extend the Garage

As I mentioned earlier, there are different ways to extend the garage. The option you select will depend on why you are extending the garage and the available lot size.

1. Garage Bump-out Addition

Bump-outs are becoming popular because it’s the most cost-effective way to add space to an existing room. Besides the garage, bump-outs can be done for a bedroom, a bathroom, or even the kitchen.

But what are bump-outs?

Bump-out addition is a way to extend the square footage of an existing room by attaching a smaller room to it. The smaller room is known as the bump-out. Bump-outs are usually not full-width as the room they are attached to and are also shorter in height.

Garage bump-out addition can be great for homeowners who want to extend their garages enough to fit their cars. For instance, let’s say your car is 3′ longer than your garage’s depth, and your car’s hood (or bonnet) is 5′ wide. A good bump size to extend the garage can be 5′ x 7′. 

This means you are extending the garage 5 feet deeper to accommodate for the extra 3 feet length of your vehicle, and then increasing the width by 7 feet so that you can fit your 6 feet wide car under the bump-out. I hope that makes sense.

If you have space at the back of your garage and want to fit a longer car into the garage, I highly recommend you go with a bump-out addition. That’s because you won’t do much structural change to your garage, and you will save a lot in the process. Bump-outs are also easier to get permits for, and builders find it relatively easier to do.

2. Extend the width of the garage

If you want to convert a single car garage into a double car garage, this is the option to for. This requires you to have at least 12 feet of available lot size on the side of the garage. That’s because you will have to extend the garage by at least 10 feet.

This extension may require excavation, will require a new foundation for the new walls that will be built, and laying of new concrete slabs. The roof will also have to be redone. 

You may also have to change your garage door from a single door to a double garage door to be able to move the two cars simultaneously. This means the garage door frame has to widen to fit a bigger-sized garage door.

Alternatively, you can add another single garage door so that each car has its own door. 

3. Extend the length or depth of the garage

If there is enough plot size at the back of the garage, another good option is to extend the depth or length of the garage. For instance, if your garage’s dimension is 12′ x 20′, you can extend the depth by 20′ to fit another car in there. So at the end of the project, you’ll have a 12′ wide and 40′ deep garage.

Unlike bump-outs, this extension will be at full-width and have the same height as your garage. Meaning you have to tear down the garage’s rear wall and extend it. The roof and concrete will have to be redone as well.

The benefits of extending the depth of the garage are, you don’t have to replace the garage door unless you are expanding from the front.

However, the downside of this option is you can move the vehicles out of the garage simultaneously. To move the vehicle, which was parked first out of the garage, you have to move the second vehicle outside before, which is a bummer. This will not be an issue if you don’t use the first car often.


You can certainly extend your garage. How big you can expand it will depend on the available lot size and your local zoning guidelines. You can either increase the width or the length of the garage or both, giving you more space to store your items.

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