How much does it cost to build a detached garage?

Reviewed by Lenny Stahl remodeling expert. Written by Fixr.com.

If your home does not currently have a garage, you may want to add one to your property for several reasons. Not only does a garage protect your car from the elements, but it can also provide extra storage space and workspace for everything from car repairs to woodworking projects. While there are benefits to both attached and detached garages, many people choose a detached garage to keep carbon monoxide fumes away from the home, or because attaching a garage to the existing structure would not work due to obstructions, or for structural and aesthetic reasons.

The cost of building a detached garage can vary considerably by location, size, materials, and finishes chosen. Typically, the cost to build a detached garage ranges between $30,000-$60,000, with the average customer paying $52,830 for building a two-car design (24’x24’) with a finished interior, asphalt shingles and vinyl siding.

Detached Garage Costs

Detached Garage Cost by Size

Primarily, the dimensions of your detached garage will hinge 10 on your needs and the available space on your property. Typically, detached garage project sizes are customized to include more than just car storage. A garage with a depth of only 20’ will not leave much room for storage or other uses. These are low-end prices, and the stand alone garage cost will increase with longer depths, interior finishes, additional levels, and customization.

1 Car Detached Garage

The minimum recommended size for a 1 car detached garage is 12’x20’. Consider adding between 4 and 10 feet to the width or depth of the garage to add more storage or work space. The one car detached garage cost should range between $22,200 and $32,000 or higher if adding square footage or additional finishes and details.

2 Car Detached Garage

A 2 car detached garage should have a minimum size of 20’x20’. Consider increasing the footprint if you have the room. Large vehicles that need more space for clearance, or a desired space for storage and working could warrant an increase in size. Expect to pay between $31,000 to $39,000 for the minimum size.

3 Car Detached Garage

Minimum dimensions for those that hope to have room for three cars is 30’x20’. Also consider this size for two cars and a workshop space. Average costs for a minimum sized 3 car detached garage are between $45,000 and $57,000.

4 Car Detached Garage

It will take a large property to have room for a 4 car detached garage. The minimum size would be 40’x20’ and this will cost between $51,000 and $67,000.

Detached RV Garage

A detached RV garage can come in many sizes since RV’s come in many sizes. For a 20’x44’ structure, which would hold most sized RV’s, expect to pay between $55,000 and $70,000. Keep in mind that an RV garage has to be taller than a traditional garage and include a larger door.

Detached Garage Cost per Square Foot

The costs of building a detached garage vary widely. A very simple structure with few finishes used only to protect vehicles will vary widely in price from a detached garage built with top quality materials and a fully finished interior. No matter the details, building a detached garage on your property will have a great return on investment. These prices reflect a one story garage only.

Detached Garage Roofing Cost by Roofing Material

Ideally, roofing on your detached garage will match or complement the other structures on your property. Durability and maintenance are also important considerations. Additionally, if you plan on using your detached garage as a place to store materials that could become flammable or dangerous, like paints, oils, fuels, or materials that give off fumes, you should consider installing a non-flammable durable roof.

Modified Bitumen

For a more traditional look, the ideal option would be modified bitumen 7 ($1.50 to $5 per square foot ). This material is inexpensive, easy to install, and will last 10 to 15 years.

Asphalt Shingles

Asphalt shingles ($2 to $5 per sq.ft.) are the most common roofing material. Most often made of fiberglass, these shingles come in a variety of colors and installation is fast and easy. Asphalt shingles can last 20 to 30 years.&

Cedar

Cedar roofing is attractive and durable. It can last 50 years if properly maintained and is not very susceptible to damage from hail. Cedar roofing costs between $4 and $10 per square foot.

Metal

Corrugated metal roofing is an attractive option with a shorter installation time and costs ranging from $5 to $10 per square foot . Other choices include aluminum, tin, galvalume, lead, metal slate, metal tile, stainless steel, rusted metal, and copper, which range from $6.50 to $20 per square foot. Metal roofs require little maintenance and can last for 40 to over 100 years.

TPO

If you are looking for a long-lasting roof, consider TPO, which is a type of rubber roof. TPO will cost between $6.50 to $11.50 per square foot and can last up to 40 years.

Tile

A tile roof may be expensive, but it is durable, low maintenance, environmentally friendly, and has a long life. However, it is difficult to install, can crack when walked on, and is not a great choice for all climates. Expect a tile roof to cost between $7.50 and $17 per square foot.

Clay

Clay ($10 to $20 per square foot) can last several generations, up to 100 years. There are many shapes and styles to choose from, however clay tiles are difficult to install and replace if broken.

Detached Garage Foundation

Possibly, the most critical decision to be made regarding building a detached garage is the foundation style. Depending on where you live, you may have a few options that are on the less expensive end of the spectrum. For obvious reasons, warm climates that rarely experience freezing temperatures allow for foundations that are simpler in design and, therefore, less expensive. On the other end of the spectrum, if you live in an area like New England, where foundations are exposed to high humidity and vastly changing temperatures, you will require greater depth and a more complex design.

If you are building a small, simple single-car garage in an area of the country that experiences year-round moderate temperatures and low relative humidity, you might consider a gravel pad, the least expensive foundation option. While this is maybe the most cost-effective option ($4 to $10 per square foot), it is rarely the most substantial or long-lasting option. The most durable foundation for your garage will always be concrete.

A garage foundation is typically constructed of concrete. There are several options for concrete foundations. These include floating slabs on grade ($6 to $12 per square foot), which is the simplest and least expensive. A floating foundation ($8 to $14 per square foot), offers mesh reinforcement for added strength as well as footers up to a depth of 12” around the perimeter. A monolithic foundation ($14 to $17 per square foot) is similar to a floating foundation, but also includes a concrete frost wall. This is ideal for places with very cold winters. A block foundation ($14 to $17 per square foot) includes 2’ wide footers with a 4” concrete floor. This provides frost protection and added support for the structure. A stem wall ($16 to $18 per square foot) is needed when creating a foundation that will include a basement.

Detached Garage Siding

It is common to choose siding for a detached garage that matches the main house on the property. However, you may choose a complimentary type of siding material to add flair, upgrade to a more durable siding material for a detached garage, or choose a cheaper option if on a budget. Here are some common siding options and their costs.

Fiber Cement Detached Garage

Fiber cement is an eco-friendly option that combines durability and style. It lasts between 25 and 40 years and can also be painted or stained like wood. Expect to pay $2.50 to $6/sq.ft.

Vinyl Detached Garage

This material lasts up to 20 years and retains color, although it is susceptible to cracks. The cost for vinyl detached garage siding is $3 to 5/sq.ft.

Metal Detached Garage

Aluminum is a good choice if you need a non-corrosive and long lasting material, it can last over 40 years. However, it is susceptible to fading and denting. As with aluminum, steel is non-corrosive and can last over 40 years. This material is also susceptible to fading and denting. Expect to pay between $5 and $10/sq.ft. for metal siding.

Stucco Detached Garage

Stucco is a durable material that is applied to a building and needs little maintenance. It is made of aggregates, a binder, and water. It can last up to 40 years and should cost between $6 and 13/sq.ft.

Wood Detached Garage

This material is quick, easy to install and ease to replace if damaged. It is also a good option for a homeowner who wants to go green. Bear in mind that wood needs regular maintenance and if properly cared for can last 15-40 years or more. Expect to pay $7 to $10/sq.ft. for wood detached garage siding.

Brick Detached Garage

Brick is very versatile and is available in a wide range of styles, textures, and colors. If properly cared for, brick can last over 50 years. The cost for this material is $8 to $15/sq.ft.

Stone Detached Garage

Stone is a very durable material that gives a natural look to any building. Prices vary widely based on the type of stone and the difficulty of installation. Expect to pay $10 to $36/sq.ft. for stone siding.

Labor Cost to Build a Detached Garage

A contractor will be able to discuss your plans with you, then hire and schedule the appropriate specialists to perform the jobs that need to get done. What state you live in will impact how much this will cost. Also, there are a number of variables that will ultimately define your labor costs overall. For example, the average per-hour fee for an electrician in the U.S. can range from $40 to $100. Additionally, electricians may charge for square footage for more complex wiring needs. Similarly, siding professionals tend to charge by the square foot, and their average hourly rate, $40 to $50 per hour, will be included in that square foot price, and roofing labor tends to also charge by the square foot at roughly $3 per square foot. If you choose high end finishes, or things like custom brick work, slate roofing, or complex HVAC, it will be reflected in the cost of labor that each professional will charge, which will affect the general labor cost as well.

Detached Garage Insulation

Whether you want to incur the expense of insulating your garage will depend on how you plan to use the space and the climate of your location. If you are building a detached garage just for car storage in Florida, insulating may not be a concern. However, if you are building a detached garage in Maine and want to use it as a woodworking shop, insulation is definitely desirable. There are many different types of insulation and each one comes with its own price tag. It is also important to realize the value of air sealing along with insulation. Garages are not usually built to be airtight and have lots of air gaps to the outdoors, letting the heat escape.

Floors and Walls

One of the great things about a detached garage project is that you can live without finished walls and flooring. If you are not going to be spending a lot of time in the garage, or you haven’t made up your mind about what other purpose the space will serve, you can leave the exterior walls as they are and simply seal the concrete foundation floor. But, if you want a more finished space, mid-grade insulation ($1-$2 per sq.ft.) and drywall ($1-$3 per sq.ft.) installation is relatively quick and affordable. Concrete floor coating, ideal for work spaces, will cost on average $3 to $10 per square foot. Although if you want to get really creative and go for something stylish, like a polymer modified overlay with elaborate designs, it could cost as much as $15 per square foot.

Two-story Detached Garage

If you are looking to add a significant amount of living or storage space to your property, you may want to consider adding a second story to your detached garage. A second story in your garage offers endless possibilities, from seasonal storage to an entire apartment. Before you start your addition project, check with your local zoning and building codes department, as there could be height restrictions. Unsurprisingly, the cost difference is substantial. On average, a two-story unfinished two-car garage primarily used for storage will average $60,000. Contrarily, a finished and insulated two-story three-car garage with full living space above will average $136,000. It should be noted that these average costs are a sampling from various parts of the country and are based on the use of lower- to mid-range siding, roofing, and finishes.

Detached Garage with Living Space

There are many options for designing a garage with living space or extra features. All possibilities will add extra costs, but could be a great return on investment for enhancing your property or providing rental income or a place for a relative to live. For all costs, we will start with a basic two-car detached garage (20’x20’) starting at $31,000.

Detached Garage with Carport

Adding a carport to a detached garage is a great way to protect another vehicle without the added cost of enclosing the extra space. Expect costs for a detached garage with carport to range from $35,000 to $45,000.

Detached Garage with Basketball Court

Upgrade the driveway and install a hoop on the garage for a small basketball court, or build a half or full court basketball court out the back. Costs will vary widely depending on size, location, and finishes and start around $35,000 and go up to $80,000.

Detached Garage with Covered Patio

A covered patio is a great place for relaxing or entertaining. Consider adding one when building a detached garage. Costs should range from $40,000 to $50,000 depending on size and desired finishes.

Detached Garage with Bonus Room

A bonus room can serve many purposes. Possibilities are a workshop, greenhouse, storage room, craft room, play space for the kids, office, or guest room. A bonus room could be built above the garage or be an extra room on the same level. Costs will vary depending on the size and finishes needed to complete the space. Expect costs for a detached garage with bonus room to range from $44,000 to $60,000.

Detached Garage with Deck on Top

A rooftop deck can provide a great place to host a party or family gathering. When building a new structure, it is a great time to add one. Costs will vary widely, depending on materials and finishes, including pergolas and outdoor kitchens. Expect costs for a detached garage with deck on top to start around $45,000 and go up to $60,000.

Detached Garage with Basement

Consider building a detached garage with basement if you are looking to add a safe place to retreat to in inclement weather, a wine cellar, or would like extra space for storage or a workshop. Building a basement requires a large amount of land preparation and digging. Expect the cost for a detached garage with basement to range from $48,000 for a simple open space to $80,000 for a design requiring more finishes.

Detached Garage with Loft

The cost to build a detached garage with room above will vary greatly depending on the intended use. If the room will simply be used for extra storage and will not need to be finished or include HVAC, plumbing, or electrical, it will be considerably less expensive. However, the detached garage with apartment cost will be much higher because of the need to finish the space and include electrical, plumbing, and HVAC. Costs for a detached garage with loft will range from $60,000 to $90,000.

Prep-work

One of the first and most important considerations that you must factor into building a detached garage is the location on your property. A land survey, which will cost about $575, is required before any work can commence. Once the survey is completed permits are obtained, work can begin.

Excavation and site preparation costs are unique to each property and can increase with many factors. This site preparation may include tree and brush removal, previous structure removal, excavation, erosion control, re-sloping, leveling, and dirt replacement. Tree and brush removal will range in cost from $200 to $2,000. Minor demolition projects average about $1,000. Erosion control will run about $10 per 4’ section, and resloping averages $985 for a 1,000 sq.ft. area. Grading and dirt replacement ranges from $19.59 to $43.20 per sq.ft.

Benefits of a Detached Garage

As with any home improvement project, there are pros and cons to building a detached garage. The decision will depend on what your goals and needs are regarding extra space, the limitations of the existing property, and of course finances.

Although the construction of a detached garage is from scratch and more expensive, you will still need to venture into inclement weather to reach your car and install a driveway or redesign your current one. Either way, detached garages have many benefits. It keeps the family safe from carbon monoxide fumes, you have more freedom to choose the design. Moreover, a detached garage adds extra storage or workshop space and offers more privacy if you have living space included in your plans.

Detached Garage Designs

There are many stand alone garage designs to consider when building a new structure. Many will choose to keep the same theme of the main house on the property, while others may branch out. For instance, a cape cod detached garage will have a steep angled roof, shutters on the windows, and look like an old home by the sea in New England. These design elements will add an extra cost of $7,000 to $20,000 to the garage. A modern detached garage will likely incorporate a variety of construction materials, including iron, stone, and wood. The shape is usually square and this design will add about $8,000 to $25,000 to the cost of the garage. Other possible designs include colonial, country, Northwest, Southwest, farmhouse, Tudor, Victorian, or rustic. Each of these designs will add more costs to the project to account for the need for extra design and oftentimes, more and higher quality construction materials.

Detached Garage Driveway

For easy access to your home and new detached garage, it may be necessary to extend the existing driveway or install a brand new one. An average 12’x50’ asphalt paved driveway will cost approximately $830. Another similarly affordable option for driveways, around $800, is the less durable gravel, but you may prefer the look of something more decorative like brick pavers, with averages $11,630, or stamped concrete, averaging $7,200.

Detached Garage Doors

The average size of a garage door is 9’x7’. Double-width doors are available if you would like a single door for a two-car garage, but additional structural support will be a necessary added expense. As with most components in the garage, you will find an extraordinary number of options in materials, colors, and styles of garage doors. Since the garage door may be the first thing that people see as they approach your property, and curb appeal is so important, aesthetics is undoubtedly a significant influence on the decision. Also, durability, ease of function, energy efficiency, and longevity should factor into choosing the right garage door. On average, a garage door costs between $500 and $1,100, although the price will increase with options such as insulation, windows, automatic openers, and other custom features.Garage doors are available in a variety of materials, all with specific benefits and are more suited to certain environments.

The overhead door is your garage's largest moving part — and with an average of six up-and-downs a day, it's also one of the most used. This is why garage door choice and maintenance are important.

​Lenny Stahl, outdoor storage structures expert

Vinyl ($600-$800) and aluminum doors ($800-$1,300) are lightweight and generally less expensive. Fiberglass ($1,150-$2,250) and steel ($400-$2,000) deliver on durability, while wood doors ($2,000-$2,800) open up your project to touches of personal style and creativity.

A garage door opener makes it convenient to open the garage without leaving your vehicle. An exterior keypad, as well as an interior button, will also open the garage door, eliminating the need to hoist the door open yourself. Costs for basic garage door openers start around $300 installed and go up to about $650 if desiring special features such as WiFi connectivity or battery backup.

Pedestrian Detached Garage Door

Ease of access through a pedestrian door, typically 32”wide x 78” high, is appealing to some homeowners, as is the additional natural light allowed with a windowed door. Of course, if your new garage space is to include working or living areas, a pedestrian door may even be required by your homeowner's insurance and local building codes. More often than not, steel exterior pedestrian doors ($500 to $700) are chosen for their durability, security, and energy efficiency.

Detached Garage Windows

Windows, while not required, are desirable for maximizing natural light. With customization, and room in the budget, windows for your detached garage ($550 per window on average) can come in a seemingly endless array of options. However, the most common sizes that you will see are 18”x36”, 24”x36”, and 30”x36”. Similarly, skylights ($650 to $3,800) offer intense natural light and energy-efficient heat in the colder months. Unfortunately, skylights are notoriously high-maintenance, leak-prone, and require repairs every few years.

Detached Garage Electrical Wiring

Decisions about electrical and lighting will depend entirely on what the detached garage will be and the purposes that it will serve. If it is merely going to be a spot to protect your car from the elements, then necessary wiring for a single overhead light, or perhaps, electric to an automatic door opener will suffice. Otherwise, consulting an electrician about any of a myriad of possibilities is advisable. Electricians usually charge between $40 and $100. Surely, if living or workspace is considered, then lighting and electrical will be more extensive, especially when considering HVAC.

Detached Garage Lighting

Lighting may be desired inside the garage, as well as outside the garage for security and safety reasons. These lights can be installed by an electrician, who generally charges $40 to $100 per hour. Popular choices for indoor garage lighting include shop lights ($30 to $70 per light, plus labor), flush mount lighting ($90 to $200 per light, plus labor), high bay lighting ($85 to $140 per light, plus labor), and recessed lighting ($10 to 25 per light, plus labor). Shop lights give a traditional look in a garage and hang by a chain. They are the quickest, easiest, and cheapest way to light a garage. High bay lighting is great for large garages with high ceilings. Flush mount or recessed lighting are best for garages with lower ceilings. A good rule to follow for basic lighting is to have a minimum of one 8-foot fixture for each vehicle space. Workspaces will need extra lighting.

Floodlights or wall lanterns can be installed on the exterior of a detached garage. Choose exterior lights activated by a motion sensor for safety, or ones that turn on and off with a switch. Wall lanterns typically cost $100 to $150 each, plus installation. Floodlights typically cost $75 to $150 each plus installation.

Detached Garage with Breezeway

A semi detached garage is a garage that is connected to the house with a breezeway. This is a good option if you would like the garage to remain separate from the house, but would also like to be protected from the elements when going in and out of the house. Keep in mind that an entry door may need to be cut into the house if there is not one present already. The costs for this project will be similar to building a detached garage, with the added cost of building the breezeway, likely between $3,000 and $6,000.

Enhancement and Improvement Costs

Gutters on Garage

Gutters may not seem like a necessity for a garage, especially if it is only to be used for basic storage and a vehicle. Although at an average cost of $3 - $9 per linear foot you may consider this as a necessary expense. Gutters will keep rainwater away from your structure, prevent rotting and water damage, and save money on maintenance and repairs in the long run.

HVAC

As with many of the options mentioned above, HVAC will be a personal choice based on the purpose of your detached garage and your location. Average costs are $2,000 for ductwork, $4,000 for furnace installation, and $2,500 for air conditioning. In some areas of the country, a garage with a second story that will be used as a living space would require HVAC, particularly where freezing pipes or humidity damage could be an issue.

Stone Veneer Around Garage Door

For those that would like to add a decorative touch to your detached garage, adding stone veneer to the front siding of your garage is the perfect option. Stone veneer is significantly less expensive than other material options ($10 - $20 per square foot), and it can really enhance the appearance of your garage.

Detached Garage with Porch

Adding a porch can provide a great place to sit back and relax or entertain friends and family. Consider a nice railing or have the porch remain open to the yard or driveway. Dress it up with patio furniture, a table, and an outdoor rug. The average cost to build a porch ranges from $17,000 to $25,000.

Detached Garage with Bathroom

Adding a bathroom to a detached garage will save time from having to make extra trips into the house. This can be ideal if using a portion of the garage for a workshop or a bonus room for housing guests. Expect costs to be around $12,000 for a half bathroom, $35,000 for a ¾ bathroom, or $47,000 for a full bathroom. This could be less if plumbing and electrical are already present in the garage

Additional Considerations and Costs

• Permits. Many of the jobs needed to build a detached garage would require the work of licensed professionals. Permit costs for new construction vary from county to county and state to state. The cost for permits is figured by a formula that takes into account square footage and the cost of materials. The average cost of a building permit for a new 576 square foot detached garage would be about $500. Additionally, your town may require a planning permit (average $30) prior to receiving a building permit.
• Inspections. An inspection post construction to ensure that the building meets all local and state building codes, particularly structural and electrical, are vast and detailed. For your detached garage to pass the final inspection it is necessary to have someone familiar with the code books doing the work for you.
• DIY. While some of the finish work could be considered DIY, it is advisable to hire a contractor to handle the bulk of garage construction. Pulling permits for the job, hiring licensed subcontractors, planning, scheduling, and handling inspections are just a few reasons to leave this job to a pro.
• Further additions. The planned use of your detached garage will dictate even more considerations, such as plumbing, architectural and interior design costs, decor, and furnishings.
• Replicating looks. If you already have tile or slate shingles on the other structures on your property, you may consider replicating the look on your new garage. However, these labor-intensive choices will cost more than $15 per square foot.
• Roof trussing costs. These will depend on personal aesthetic and function choices. For instance, roof truss pitches allowing room for a subfloor, storage attic, or living space (which would also include 2nd story floor joists) all add to the cost of your framing.
• Prefab detached garage cost. A prefab garage could be a great choice if looking for a simple structure to protect your car. These structures do not have much room for modifications and upgrades. A prefab garage starts around $4,000, with models costing more than $10,000.
• Taxes. If you’re curious about attached vs. detached garage taxes, it will entirely depend on how your municipality defines “liveable space.” When considering construction, your first stop should be a trip to your county or city’s tax auditor’s office. Some municipalities do not allow liveable space to include detached “outbuildings” on a property, so even if you build a detached garage that’s “finished” (with paint and utilities), that space is not counted for property tax purposes. On the other hand, if you finish your attached garage to look more like an additional room than a garage, some municipalities will add that to your home’s total square footage, and your property taxes will increase.

References

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