Convert Two Singles to Double: Garage Expansion Guide

Joan Aug 08, 2026

Looking to maximize your garage space? You might be wondering, "Can you convert two single garages into one double?" The short answer is yes. However, there's more to consider than just combining two spaces. Let's delve into the aspects you should weigh, from layout and renovation, to legality and cost.

23 Incredible Garage Conversion Ideas to Maximize Your Home’s Potential
23 Incredible Garage Conversion Ideas to Maximize Your Home’s Potential

Expanding your garage can significantly increase your property's value and functionality. But before you grab your tools, here are two crucial aspects to consider:

Double garage door conversion with SWS SeceuroGlide LT insulated roller garage door in black
Double garage door conversion with SWS SeceuroGlide LT insulated roller garage door in black

Garage Design and Layout

When merging two single garages into one double, you'll have a space substantially larger than the standard 20x22 ft. Here's how to make the most of it:

Project Update: 🛠️🏠 Garage to Apartment Conversion! 40x20 garage into an 800 sqft apartment! 🚪🛋️
Project Update: 🛠️🏠 Garage to Apartment Conversion! 40x20 garage into an 800 sqft apartment! 🚪🛋️

Optimal Dimensions

Most double garages are around 20x24 ft., providing ample room for two cars and additional storage. However, your combined garage could be larger, allowing for a Stirnwall or tray ceiling to add height and volume. This could accommodateRV parking or a bonus room above.

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DIY Garage Conversion: Building a Home Office on a Budget

Consider deducting a few feet from the shared wall for a workbench, cabinets, or utilities. This will create a functional, multi-use space while keeping each garage bay generously sized.

Drive-In Angle and Door Placement

To accommodate vehicle entry and provide adequate clearance, plan your drive-in angle and door placement carefully. The standard door size is 9x8 ft., but if you own larger vehicles, consider oversized doors.

Detached Garage Conversion Ideas Uk
Detached Garage Conversion Ideas Uk

Calculate the turning radius for your largest vehicle, ensuring it can safely navigate the garage. You might need to adjust the drive-in angle to achieve this.

Legal Requirements and Cost Considerations

Before you embark on your garage conversion project, check the following:

40 Garage Conversion Ideas to Maximize Your Home
40 Garage Conversion Ideas to Maximize Your Home

Zoning Laws and Building Codes

Your local zoning laws might dictate the size, height, and usage of your garage. Building codes may require specific materials, like fire-rated doors or Carmulated roofing, for structural and fire safety. Consult your local building department for precise regulations.

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How to Convert Your Garage
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Two-Car Garage Conversion Floor Plan Ideas - Creating Extra Living Space at Home
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This Cluttered 1980s Two-Car Garage Was a Chaotic Dumping Ground Crying Out for Order — See the 26 Before & After Design Ideas

Additionally, check if your project requires a building permit. If so, submit your plans for approval before starting work.

Budget Allocation

The cost of converting two single garages into one double can vary significantly, depending on factors like materials, labor, and local regulations. On average, expect to spend around $6,000 to $10,000 for a basic conversion. Here's a rough breakdown:

  • Demolition and site preparation: $500 - $1,000
  • Foundation work (if needed): $1,000 - $5,000
  • Roofing, siding, and insulation: $1,500 - $3,500
  • Door installation: $500 - $1,500
  • Interior finish and parking slab: $2,000 - $4,000

Keep in mind that these are rough estimates, and your actual costs may be higher or lower based on your locale and project specifics. Don't forget to factor in a contingency fund (around 10-20% of the total budget) for unexpected expenses.

When you're ready to transform your two single garages into one double, consider hiring a professional architect or garage conversion specialist. They can provide personalized advice, help navigate zoning laws and building codes, and ensure your project is a success. With careful planning and execution, your double garage will soon become a valuable asset to your home.