Building a garage extension costs $10,000 on average, but ranges between $3,500 and $14,000, depending on the size, scope, and details of the project.
If you’re adding more space to your existing garage, you can expect a garage extension cost of around $10,000, with costs commonly ranging from $3,500 to $14,000 or more. Building a garage extension is an excellent way to give yourself more space for work, recreation, and storing your belongings. To ensure you build an area that suits your specific needs, it's important to understand all the garage extension costs. Here's a close look at what to expect when making your plan.
The cost to extend a garage is about the same cost to build a new garage, and similar to the cost to remodel a garage. That's because the project requires all the same steps, from pouring a new foundation to installing a new roof.
On average, a garage extension costs $40 to $70 per square foot. If your project requires knocking down an exterior wall, expect to pay on the higher side.
Here are some common garage sizes and configurations when extending a garage, including total project costs:
| Project | Size of Extension | Cost |
|---|---|---|
| Convert 1 car to 2 car | 8 x 20 feet | $6,400–$11,000 |
| Convert 2 car to 3 car | 10 x 20 feet | $8,000–$14,000 |
| Convert 1 car to 3 car | 22 x 22 feet | $19,360–$33,800 |
When determining how much you'll spend to extend a garage, you'll find that you can divide project costs into preparation, demolition, and building.
As your garage extension will involve some level of new construction, it's wise to hire a structural engineer to review your design plans and help you draw up blueprints. The cost of hiring a structural engineer is 1% to 20% of your project budget, which translates to $200 to $1,500 for a build of easy to medium complexity.
Many municipalities require construction permits when you renovate your home. These permits pay for recording your improvements in official documents and later inspections to ensure soundness. Depending on your area, permitting may cost you $200 to $1,500.
Depending on how exactly you intend to extend your garage, it may be necessary to complete some demolition. This will be the case if you add on to your garage width-wise, as you'll need to knock down part of an exterior wall to build outwards.
As all exterior walls are load-bearing, the cost to remove a wall ranges from $1,200 to $3,000. Aside from the complexity of working with load-bearing walls, there may also be plumbing and electrical concerns within walls, so it's always best to leave this type of work to a professional.
If you don't plan to manage the construction of your garage extension, you'll need to hire a local contractor to oversee the project. You'll pay this professional 10% to 20% of the overall project cost to manage things for you.
The cost of building a foundation for your garage to sit on will range from $4 to $25 per square foot, depending on the type you need. A monolithic concrete slab will usually work, but local conditions could require a stem wall slab or pier and beam construction instead.
Framing involves building out the new skeleton for your garage addition. When you hire a local framer, you can expect to pay $4 to $8 per square foot for new walls and beams.
With new square footage in your garage extension, you'll likely need more electrical outlets to power tools and other accessories. You may also need wiring throughout the walls and ceiling for light fixtures, garage doors, and alarms. The average cost to hire an electrician is $50 to $100 per hour.
When you build onto your garage, you may find yourself with room for a new washtub or even your washer and dryer. As an exterior wall may have been demolished or moved, you might also need a new spigot outside for a hose. The cost to hire a plumber to add new piping and fixtures runs from $45 to $200 per hour.
The cost of roofing your garage can range from $1,000 to $3,000, mostly dependent on whether your contractor can simply add on to your existing roofline or needs to remove the old roof and build a new one.
One of the final steps of extending a garage may include adding a new garage door or replacing your existing one with something larger. This may be a necessity if you build your garage wider or extend the front of it, but you might not need it if your construction took place at the back of the garage. The cost for garage door installation runs from $750 to $3,000, depending on whether you need to add a door, upgrade to a two or three-car unit, or need a new opener. The local garage builder you hire can often handle this step of the project. However, the builder may subcontract the work.
| Siding Type | Cost Range (per Square Foot) |
|---|---|
| Stucco | $7–$9 |
| Vinyl | $3–$12 |
| Wood | $1–$15 |
| Brick | $10–$20 |
| Stone | $7–$30 |
| Fiber Cement | $5–$14 |
Once the garage is built, it's time to turn your attention to finishing it out. In most cases, your existing home finish will determine what you'll use for the garage. For example, if your home has a stucco exterior, you'll likely continue that with your garage. The same applies if you have cedar or vinyl siding. Assuming you have a stucco exterior and drywall or cinder block interior, at the very least you'll need to pay for painting. If you hire a pro, expect to pay $1 to $6 per square foot to paint the interior and exterior.
On average, it costs $40 to $70 per square foot to extend a garage. Labor alone makes up 50% to 70% of the finished project cost, meaning you save $20 to $50 per square foot if you do a DIY renovation.
To break this down further, let's consider a garage extension of 200 square feet, which is about what you'll do if you extend a garage to hold three cars rather than two. If you pay a professional to do the job, you'll spend $8,000 to $14,000 in material and labor costs. However, if you complete the project on your own, you could spend as little as $4,000 just for materials.
There's no doubt that completing a garage extension on your own can result in significant savings, but just looking at numbers doesn't offer a real appreciation for the hard work that goes into the construction project. Extending your garage requires significant skill as you'll be dealing with load-bearing walls, electrical, and general construction. Not getting a building project right can present a significant danger to yourself and anyone who enters your home. Unless you're a pro, this really is a job better left to those who are more qualified.
As the cost to extend a garage is $40 to $70 per square foot, the easiest way to reduce how much you'll pay for the project is to limit how much extra you add on. You can generally do this by spending extra time in the planning stage. Note that it may require some sacrifice on your part, such as forgoing having the washer and dryer in the garage or not including a sink for washing up.
Another way to cut costs when completing a renovation project is to take on aspects of the job yourself. Even the most novice DIYers can tackle interior painting, but if you have more experience, you may also be able to handle exterior painting or installing a new garage door opener. Leaving the interior unfinished if possible, can avoid or at least delay the cost of drywalling the garage or the cost of insulating the garage.
Katy Willis contributed to this piece.
It makes sense to extend your garage if you need more room to work or store your belongings. In addition to having that extra breathing room, you don't have to worry about the money you spend on the project going down the drain. As far as the value a garage adds to a home, you can often recoup 75% to 85% of your investment into a garage extension or garage bump-out addition.
The cost to tear down a garage averages $2,000 to $10,000. You might consider this option if your existing garage is damaged beyond repair or if you have grand renovation ideas that are best suited to a fresh build.
Other ways exist to increase the usefulness of your garage space. There are even options for turning your carport into a garage. Another method is to extend the length of your garage by making it deeper. The process is similar to traditional garage extensions. However, the end product is a garage with a different floorplan rather than additional parking spaces to accommodate more storage or other space.
