How to build a metal garage

Last updated: 4 June 2024
steel framed garage building

Careful planning is vital to ensure you get the right metal garage building at the right price. Try to consider what you will use your building for now and further into the future.

Step 1: Planning

What Size Garage Do You Need?

Metal garage kits are available in widths from 30’ to 100’ (in increments of 10’) with unlimited lengths. Our most popular garage sizes are 30x40 garages (3-8 cars) or 30x50 (4-10 cars), and 40x60 (6-15 cars).

The overall garage dimensions will be governed by the number of vehicles you intend to store. You will need about 240 square feet for cars and 300 square feet for medium-sized trucks. This allows for two feet of clearance on either side of the vehicle and three feet down the length (for doors to open fully).

If the garage is to be used for long-term vehicle storage, you should allow 150 square feet for cars and 200 square feet for trucks.

Creating a metal garage plan can be a useful tool in this planning process, allowing you to accurately visualize the space and ensure that it meets your current and future needs.

Visualize your layout with our garage floor plan design tool, or view our sample garage floor plans.

What Height Garage Do You Need?

The eave height of your building will be dictated by what type of vehicles you intend to store in the garage. Typical eave heights include 10’ or 12’ for cars and trucks and 14’-18’ for oversized vehicles, trailers, and boats. Steel garages require a 2’ clearance above the door opening and the building's eave height. So, if you need a 10’ overhead door, choose a 12’ eave height (the most common option). A garage with a 12’ eave height will also allow you to use a car lift inside (if required).

Other garage size considerations include:

  • How much storage or workshop space will you require?
  • Will you require a half bathroom? (if so, allow approx. 25 sq ft)
  • Will you need office space? (if so, allow approx. 80-120 sq ft)
  • Will you require space for garden machinery, an ATV, or a boat?
  • Will you need a second-story loft apartment? (If so, choose a height of 16’ to 20’)


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TIP: Choose as large a garage as your budget and space allow. The #1 complaint we hear is, ‘I wish I had opted for a slightly larger size.’

How Many Framed Openings Will You Need?

Framed openings are required for all door openings. Typically one framed opening is provided for a personnel door and one for a typical garage door. You will need to decide how many additional framed openings you will require for parking bays and what size these need to be.

Please note that each of these will add to the overall cost of your garage, as additional steel is required for each framed opening.

Metal building framed openings for doors

Metal building framed openings for doors

Is a Building Permit Required For a New Garage?

A building permit will be required, but some rural and farm properties are exempt. Check with your local municipality or county building department once you have decided on a site and size for your building. You won’t be able to apply for building and foundation permits until you’ve ordered your garage and received engineering drawings from your chosen supplier.

Our garage suppliers provide metal buildings that are engineered to meet or exceed local codes throughout the United States and Canada for wind, snow, and seismic conditions.

For more details, see our article on planning a metal building project.

Will You Require financing?

Several options are available for financing steel garage kits; see our guide to financing a metal building for more details. If financing is required, identify suitable lenders at this stage. You will not be able to make the loan application until you have finalized all your building details and are at the pre-construction stage.

Step 2: Design

Choose a Garage Roof Style and Pitch

The most popular roof style for garages is the gable roof, with a pitch of 1:12 to 4:12. Single slope (or shed roof) profiles are also popular if you are looking for a more modern garage design; these typically have a pitch of either 1:12 or 2:12.

For more, see our guide to metal roofing.

Pick Custom Garage Options

Get precisely the garage you need - all buildings are custom-designed to your exact specifications.
Most customers require a standard building package, but a wide range of customization options are available that allow you to configure and style the garage to meet your requirements.

Garage siding and roofing colors

Garage siding and roofing colors

Some of the more popular options include:

Color options: Make a statement or complement your home by choosing from over twenty colors for roofing, siding, trim, wainscot and doors.

Door options: Choose from either sectional or roll-up overhead garage doors, and pick sizes that will accommodate your vehicles.

Siding options: Metal garages come standard with PBR metal siding, but you can replace this with a selection of other materials, including Hardie board, stucco, or faux stone panels.

Structural options: Consider adding a lean-to for additional covered parking or add a mezzanine level for second-level storage, office space, rec room, or living quarters.

No need to hire an architect. Our building suppliers will assist you in designing your ideal prefab garage and advise you on options to best suit your needs in terms of aesthetics and functionality.

For an in-depth look at each option, read our guide to customizing a metal garage.

Looking for inspiration? See our collection of garage design ideas.

Garage with mezzanine loft storage area

Garage with mezzanine loft storage area
Credit: u/yellow68camaro

Step 3: Ordering and contracting

Once you have a reasonable idea of your garage's size, style, and design, the next step is to get quotes for the garage kit. We can help with this - tell us about your project, and we will match you with FOUR reputable building suppliers who will provide competitive quotes for your metal garage kit. Request competing quotes from local suppliers.

After selecting a supplier to work with, you will place a building deposit (typically 20-30%) and sign a contract before the factory can begin engineering your custom garage. You will then receive (typically in 2-3 weeks) a set of building and foundation (anchor bolt) plans stamped by an engineer licensed for your state. Building plans are typically included, but some suppliers charge extra for foundation plans. So be sure to verify this before you place your order.

Armed with all the relevant plans, you can now get quotes from local subcontractors or a general contractor to facilitate the construction of your garage. You will also be able to:

  • approach your local building department and begin the permitting process and
  • talk to lenders if you require financing.

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Step 4: Pre-construction

Site Preparation

Thorough site preparation is critical. You’ll need to consider:

  • Room for setbacks.
  • Location of current utilities and access routes.
  • The ability of the ground to support the building.
  • Any easements on the property.
Site preparation for a garage building project

Preparing the construction site will include:

  • Surveying.
  • Site clearing.
  • Soil perc test and analysis.
  • Preparation of a map of the area, including access.
  • Possible excavation and addition of fill.
  • The building area must be graded (levelled). Correct compacting of the soil is critical.

Run Services To The Job Site

A professional must identify existing power, water, and gas lines in the construction area. Then, a licensed contractor must pull the permits to have the gas, water, and power lines run from your home’s lines.
If you are using your well to supply this building, check that the current pump and pressure tank can handle the new demand. Read more about construction site preparation.

Pour The Garage Foundation

Metal buildings require a slab-on-grade foundation. The foundation and anchor bolts are not included in the price, so allow for $4-$8 per square foot for this.

Foundation plans designed by a licensed structural engineer will be required for permitting purposes and to verify code requirements are met.


Garage concrete slab foundation

Garage concrete slab foundation

Unless you have extensive experience in installing foundations, we highly recommend that you have the foundation poured by professionals.

A 4” slab foundation will work for most garages, but a 6” foundation will be required if you intend to store heavy equipment or if a car lift is going to be installed.

Consider adding in-floor heating at this stage. Also, consider installing a drain for wastewater (either a square bell trap drain or a trench drain). Read our in-depth guide to foundations.

Prep For Delivery

Metal buildings are typically ready for delivery 4-16 weeks after you place your order.
Ensure you have lifting equipment (backhoe, forklift, etc.) at your job site to offload the framing, siding, and component packages and a place to store these before construction.

metal garage installation

Metal garage installation
Credit: u/domino666

Step 5: Construction

The final balance of payment will also typically be due upon delivery. Read more on what to expect on delivery day.

Construction: Three options

DIY build: You complete all the work yourself… pour the foundation, erect the garage structure, install insulation, and complete any other interior finishing.

All metal garage kits are designed for simple DIY construction and include all primary and secondary framing, siding, roof sheeting, nuts, bolts, and a set of comprehensive instructions.

For garages under 3,000 square feet, approximately 50% of buyers choose to build their own garages. With some construction experience and plenty of planning, a DIY build can save you 20-30% on the total metal garage cost.

Self Build: You act as the project's general contractor (GC) and hire and manage the various subcontractors to complete the garage build. This option can save you 10-20% on the general contractor fees.

General Contractor builds: If you choose a General Contractor (GC) for your project, they will hire and manage all the subcontractors.

This option is typically the quickest and smoothest way to complete your build but is also the most expensive. GCs typically charge 10-20% of the project cost.

However, you will benefit from the experience of the GC and the ideas they bring to the project. You may also benefit from a quicker permit approval process, as many GCs have relationships with local building departments.

See our guide to metal building construction for more details.

Step 6: Finishing

Wiring Plumbing and Flooring

When you buy a steel building from one of our suppliers, you buy just the metal buildings shell, including all framing, roof, walls, and doors. You will be required to engage local contractors to take care of the wiring, lighting, heating, plumbing, flooring, and internal framing (if required).

electrical installation

Install Insulation

Insulating your garage will provide resistance to cooling in winter and overheating in summer. It also helps prevent condensation and provides a good sound barrier.

A little extra expenditure on insulation will yield significant savings in energy costs. Most garage owners opt for either fiberglass blanket or spray foam insulation for improved energy efficiency.

Insulation can be purchased from your building supplier or sourced locally.

garage insulation

Interior Framing and Finishing

Once the insulation has been installed, you can frame the interior of the garage if you require, say, an office or bathroom. Typically, the framing will be 2x4 lumber, but it is also possible to use steel framing for this. Again, hire a local framing company for this stage of the build.

Walkthrough and Final Inspection

Small problems now can turn into bigger problems later. Therefore, formal inspections should be carried out throughout construction and on completion of the build.

A final inspection will be required at this stage to complete your permit process.

The building permit process is complete once you've passed your final inspection. After that, the building inspector will usually provide you with a certificate of occupancy, confirming that your project was completed in accordance with local building codes.

See our page on steel building interiors for additional details.

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