Whether you have a classic car collection or a cherished set of power tools, building a garage is a great way to maximize storage space and protect your vehicles. Adding a garage can also boost home value—no wonder over 70% of home buyers prefer a house with one.
Building your own garage can be a fun renovation project, but also requires careful planning and knowledge. From the permit process to construction tips, our step-by-step guide will show you how to build a garage from the ground up.
Factors to Consider before Building a Garage
Building a garage from scratch is a big home improvement project that requires proper planning and consideration. How you design and build your garage mainly depends on your specific priorities. For example, will your garage be used for parking or storage? Consider these four factors to ensure your project goes smoothly:
Size
The best garage type or size for your property depends on your vehicles and needs. Consider the vehicles you want to store and whether you want extra room for storage. The standard garage sizes by vehicle are:
- Single car: At least 12 feet wide and 20 feet long
- Two cars: At least 20 feet wide and 20 feet long
- Three cars: At least 30 feet wide and 20 feet long
If you plan to use your garage as a workshop or functional indoor space, it should be large enough to store equipment, tools, and furniture with sufficient walkspace.
Permits and Zoning Laws
Many communities use zoning laws to regulate how property owners use their land, so it’s important to do your research and check with your municipality’s Department of City Planning for the necessary information. You’ll almost always need a permit to build a garage, as this ensures all construction complies with local building codes.
When submitting a building permit application, you’ll need to include the following:
- Property survey demonstrating minimum distance requirements
- Property specifications to show the location and proximity to the residence
- Site plans, such as detailed drawings of the garage design and dimensions
Cost
The cost to build a garage ranges from $10,000 to $40,000, with people spending an average of $28,000 on the project. Expenses will depend on several factors, such as:
- Square footage
- Additional features (e.g., doors, windows)
- Materials used
- Utility connections
Be mindful of the differences between an attached and detached garage. Generally, the total cost of a detached garage is much higher, as you will need to add a separate roof and establish new utility connections.
To properly build a garage from the ground up, you’ll need to invest in the following:
| Tools | Materials |
|---|---|
| Hammers/nail guns | Foundation of choice (e.g., concrete) |
| Screwdrivers | Roofing of choice (e.g., asphalt, tiles) |
| Wrenches | Doors |
| Measuring tape | Windows |
| Hand saw | Framing parts (e.g., wall studs, fasteners) |
| Power tools (drills, sanders, etc.) | Caulk |
| Concrete mixer/pourer/screed | Insulation |
| Welder | Protective gear (e.g., eyewear, gloves) |
Tip: Unless you plan on many more DIY construction projects, renting tools can help cut costs.
How to Build a Garage in 9 Steps
Now that you have all of the necessary tools and permits, you’re ready to start your DIY garage project. Round up a few extra sets of hands (or hired contractors), and follow the steps in our detailed video:
1. Plan the Layout
The first step is to review several garage design ideas to determine which layout best suits your needs. When deciding on a design, plan for the location, prioritizing a flat and level terrain. You’ll also need to consider trees, power lines, and underground pipes on your property that may obstruct construction.
An ideal layout design should address the following factors:
- The number and size of the vehicles you’ll park inside
- Room for storage, furniture, and walkable space/workspace
- Length of your driveway
- Utility connections for the intended purpose
- Additional features like windows and garage lighting
Consider consulting an architect or engineer to help design and draw out your garage plan.
2. Prepare the Construction Site
Site preparation is the next step before beginning the building process. To prepare the construction site, you’ll need to clear it of any hazardous obstructions. This includes removing debris and trees from the designated area and digging out any uneven high spots.
Tip: If any existing structures need to be demolished, check first with your city to see if they require any additional permits to do so.
After clearing the site, stake out the desired elevation for your garage slab. Use a level and string line to create a reference plane. Carefully remove or add soil to achieve the desired grade, ensuring proper drainage away from the foundation. Once graded, compact the soil using a plate compactor or tamper to ensure a stable base for the foundation and prevent future settling.
3.Choose a Foundation
The next step in building a garage is choosing the right foundation style for your project. The most common type of foundation for a garage is a poured concrete slab.Concrete is fire- and insect-resistant, and is also the most suitable and stable base for areas with poor drainage and high risk of earthquakes.
Keep in mind, concrete slab foundations can take up to a week to cure properly. Be sure to allow enough time for the foundation to cure before beginning the framing process. If you’re hiring a professional for the concrete work, you can skip to step four.
If you’re installing the slab yourself, start by following the manufacturer’s instructions for mixing and pouring the concrete. After pouring the mix, use a screed to smooth and level the surface. Once it’s at your desired texture, cover the concrete surface for at least seven days to allow proper curing.
4. Frame the Structure
After the concrete foundation is cured, framing can begin. This will serve as the garage’s structural support. The most common building materials used to build a garage are wood, steel, brick, and concrete.
Use a saw to cut the framing materials to size, ensuring the blade of your saw is correct for the type of material. If you’re following a garage kit diagram, assemble the framing according to the manufacturer’s instructions. Otherwise, follow these steps:
- Attach the sill plate to your foundation.
- Install floor joists, if applicable.
- Install subflooring (plywood), if applicable.
- Install vertical posts or “studs” where you’ll place the interior and exterior walls.
- Leave openings for your doors and windows, taking this opportunity to install window sills and headers.
- Raise the walls and attach the top plates.
- Attach the ceiling joists, tie beams, and rafters.
Once you have a secure frame, you’re ready for the next step.
5. Install the Roof
Once the framing is in place, move on to the roofing portion. Begin by ensuring your walls are level, followed by laying down a water-resistant membrane on the top plate of the walls. This initial layer provides a critical barrier against water infiltration.
Next, start laying your roof decking or “sheathing” material of choice, such as metal roof panels and asphalt shingles. Begin at the eaves (the lowest edge) and work your way up the roof, ensuring proper overlapping and nailing each shingle securely. Install flashing around chimneys, vents, and valleys to prevent leaks in these critical areas.
6. Install Doors and Windows
Install pre-hung windows and doors into the respective garage frame openings, according to manufacturer instructions. Make sure they’re properly sealed and secure by testing them to see if they all open, close, and lock properly.
7. Add the Siding and Exterior Finishing
Complete the exterior by installing exterior wall sheathing (e.g., plywood) followed by your siding material of choice (vinyl, wood, metal, etc.). Follow the manufacturer’s instructions for installation, making sure the sheathing is securely fastened with no gaps.
For the siding, you’ll generally start at the bottom and work your way up, ensuring there is proper overlapping and fastening of each panel. Finally, install corner trim pieces and the window and door trim for a finished look. Don’t forget to caulk in gaps to prevent leaks.
8. Add Interior Finishing (Optional)
Once you complete the outer structure of your garage, you can install electrical wiring. Unless you have professional electrical experience, it’s best to leave this step to a certified electrician.
Safety tip: Many insulation types are harmful if inhaled or exposed to the eyes and skin. Read all instructions carefully, and wear protective gloves, goggles, respiratory protection, and other protective clothing.
After that, you have the option to transform the “bare bones” of your garage into a functional indoor space with interior walls and floors:
- Add insulation (if desired) between the framing to help regulate the temperature inside. Common types of garage insulation include fiberglass, spray foam, and double bubble.
- Choose your desired wall and ceiling finishes, such as drywall and paint, for a clean and finished look.
- For the garage floor, choose a durable and low-maintenance material like epoxy coating or tiles.
9. Install the Garage Door
Following the manufacturer’s instructions, carefully assemble your garage door sections, tracks, and hardware. You may also need to attach the springs and rollers to the door frame. Carefully lift the assembled garage door into the opening and secure it to the mounting brackets on either side. Adjust the springs and opener as needed.
The last and final step is to test your garage door’s opening and closing functionality, including any automatic opener system. Keep in mind that garage doors are heavy, so consider having a helper for this step.
Building a Garage FAQ
Is it cheaper to build or buy a garage?
While you’ll spend on average $28,000 to build a garage from the ground up, buying a pre-built or “prefab garage” can cost as low as $6,500 and is a cheaper alternative.
What is the cheapest construction method for a garage?
Prefab garage kits and post-frame construction are two cheaper alternatives for building a garage. Both methods require fewer building materials and are much quicker to assemble than the traditional site-built garage.
Can you build a garage by yourself?
Building a garage by yourself is possible with the right tools, equipment, and planning. However, certain steps of garage construction require professional experience, such as for site excavation, electrical wiring, and certain installations. If you want to DIY a garage project, the easiest method is with a pre-built garage kit.
Customize and Order Your Perfect Garage
If a DIY garage project is too expensive or isn’t your thing, prefab metal garages are the next best thing. These pre-made structures are a fraction of the cost to build a garage, saving you both time and money.
From multiple sizes and colors to various features and roof styles, prefab garages are fully customizable to meet your needs. Best of all, these high-quality metal buildings are fireproof, weather-proof, and rot-resistant. can
When you order your metal garage through Alan’s Factory Outlet, we offer both free shipping and installation, giving you the best bang for your buck. Use our garage customization tool to explore the possibilities.
Alan Bernau Jr. is the founder and owner of Alan’s Factory Outlet. He has helped more than 75,000 homeowners design and install custom carports and garages over the last 20 years.
