Detached Garage Cost: Average Prices & Cost Factors

A detached garage stands apart from the house, so it needs its own foundation, four full walls, a roof, and often its own electrical service. The headline range above comes from a This Old House guide that prices garages of different sizes without splitting attached from detached. Detached figures from another source follow further down.

The prices were checked on Oct 13, 2026. They are national figures for a finished structure, and the final number depends on size, materials, site conditions, and local labor rates.

Size sets most of the price. The This Old House table runs from a small one-car garage at $18,000 to a three-car garage at $53,800. A standard two-car garage of 400 square feet is listed at $36,000.

Detached figures come from HomeLight, which compiles HomeAdvisor data. They show the same pattern with more detail for detached builds.

On that data, a detached garage averages $31,908. A one-car detached garage runs $11,500 – $20,200, a two-car garage $23,000 – $40,300, a three-car garage $36,000 – $63,000, and a four-car garage $41,000 – $71,100. The ranges are wide because materials, finishes, and site work vary so much from one lot to the next.

An attached garage shares a wall and often a roofline with the house, so it uses less material and can tie into existing utilities. A detached garage needs all four walls and usually its own foundation. Extending electrical service to a separate building can also add trenching and wiring work. The extra cost depends on how far the garage sits from the house and what the soil is like.

Guides disagree because they measure different things. One may price a basic structure and another a finished, insulated building with a loft. Some count permits and site work, and some leave them out.

This Old House lists the full garage range at $18,000 – $53,800. HomeLight reports a narrower range for a two-car detached garage from HomeAdvisor data, $23,000 – $40,300. These are not the same size or scope, so they should not be read as a disagreement about one price.

Beyond the structure itself, a garage build includes several line items that are easy to overlook. Some of them are listed below.

• Foundation. A concrete slab costs $4 – $8/sq ft at This Old House. HomeLight lists the foundation for a 20 by 20 foot two-car garage at $2,124 – $3,324.
• Labor. HomeLight, citing Fixr, reports labor at $20 – $30/sq ft.
• Permits. Expect $1,200 – $1,500 for a garage permit, though fees depend on the city or county.
• Loft or living space. A room above the garage costs more, at $180 – $210/sq ft in HomeLight's figures, so a loft adds to the build cost.

• Size and number of bays. More cars mean more floor area, more framing, and a larger foundation.
• Materials. Siding, roofing, and door choices change the price. Vinyl and metal cost less than brick or stone veneer.
• Foundation type. A simple slab on level ground costs less than footings on a slope or poor soil.
• Utilities. Power, lighting, and any plumbing add cost, and the price rises with trench length.
• Site prep. Clearing, grading, and drainage work can be a significant extra.
• Finishes. Insulation, drywall, windows, and a finished floor add cost beyond the basic shell.
• Garage doors. Door material, size, and opener type each shift the total.
• Local permits and codes. Setbacks, height limits, and inspections vary by town.

A custom build gives full control over size and style, and it is usually the most expensive route. Kit or prefab garages arrive with a set of components and can cost less, although you still pay for the foundation, delivery, assembly, and permits. Ask any seller whether the quote covers installation and site work. For structural, electrical, and permit questions, work with a licensed general contractor.

1. Is the quote for a finished garage or just the shell?
2. Does the price include the foundation, electrical, and permits?
3. Who handles site grading and drainage?
4. What are the payment terms and timeline?
5. Is the contractor licensed and insured in your state?
6. What happens if the soil or utilities turn out to need extra work?

Get written, itemized quotes from at least two or three licensed contractors so you can see where the prices differ.