Detached Garage Cost Calculator
Estimate the cost to build a detached garage based on size, number of cars, material, and included features.
A detached garage construction costs $20,000 to $60,000, with a national average of $35,000. Use the calculator below to estimate your cost by size, quality tier, and location.
Last updated: March 25, 2026
Detached Garage Cost Calculator
Estimate the cost to build a detached garage based on size, number of cars, material, and included features.
Estimated Total
$43,272
Itemized Breakdown
This calculator provides estimates based on national averages adjusted for your region. Actual costs may vary significantly based on specific project conditions, contractor availability, material prices, and local market factors. Always get at least 3 quotes from licensed, insured contractors before starting your project.
Want the full picture?
Read our complete Detached Garage Construction cost guide with material comparisons, contractor tips, savings strategies, and regional pricing data.
Quick Cost Reference
Cost by Tier
Basic 20x20 (400 sq ft) single-car detached garage - wood frame, T1-11 siding, asphalt shingles, concrete slab, one standard garage door, minimal electrical
24x24 (576 sq ft) two-car detached garage - wood frame, LP SmartSide siding, architectural shingles, concrete slab, two garage doors, full electrical with subpanel, windows
24x36 (864 sq ft) carriage-style two-car garage with bonus room above - engineered lumber, shingle siding, metal roof, concrete slab with radiant heat, custom carriage doors, full electrical, plumbing rough-in
How This Calculator Works
This detached garage cost calculator estimates your total project cost from four inputs: project size, quality tier, the options you select, and your location. It combines material and labor rates for your chosen tier, adds typical permit costs, then applies a regional cost multiplier so the estimate reflects pricing in your state.
Estimates use 2026 cost data cross-referenced from multiple industry sources. Treat the result as a planning range, not a quote. Your final price depends on your specific scope, material choices, and local contractor availability, so collect at least three itemized bids before you set a budget.
What Affects Your Detached Garage Construction Cost
Size and Number of Bays
$10,000 - $40,000A single-car garage (12x20) costs $15,000-$25,000. A standard two-car garage (24x24) runs $25,000-$45,000. A three-car or oversized garage (36x24 or larger) costs $40,000-$70,000+. Cost per sq ft typically runs $35-$80 for a basic build and $60-$120 for a premium build, decreasing slightly as size increases.
Slab vs. Foundation
$3,000 - $12,000A standard 4-inch concrete slab (the most common garage foundation) costs $5-$8 per sq ft installed. For a 576 sq ft two-car garage, that is $2,900-$4,600 for the slab alone. In cold climates, the slab must have a thickened perimeter footing that extends below the frost line, adding $1,000-$3,000. Garages with living space above need full stem wall foundations.
Garage Door Choices
$800 - $5,000 per doorA standard 9x8 white steel garage door with basic springs costs $800-$1,500 installed. An insulated door with windows costs $1,200-$2,500. Carriage-style wood or fiberglass doors run $2,000-$5,000+ each. A two-car garage with two doors can range from $1,600-$10,000 just for the doors, so choose carefully as this is very visible.
Electrical and Subpanel
$1,500 - $5,000A basic garage electrical setup (2-3 circuits, overhead lighting, a few outlets) costs $1,500-$2,500. Running underground from the house, installing a 100-amp subpanel, adding EV charger wiring, and running multiple circuits for tools runs $3,000-$5,000. Plan your electrical needs carefully - adding circuits after the fact is expensive.
Bonus Room Above
$15,000 - $35,000A usable room above the garage - for storage, a workshop, or living space - requires engineered floor joists, staircase, insulation, drywall, electrical, and egress windows. This is essentially finishing a second floor and adds $15,000-$35,000+ to the project. If adding a bathroom, add another $5,000-$10,000.
Frequently Asked Questions
How much does a detached garage construction cost?
A detached garage construction costs $20,000 to $60,000 for a typical project, with a national average of $35,000. Budget projects start around $12,000, and premium work can reach $100,000. Use the calculator above for an estimate matched to your size, quality tier, and state.
How does this detached garage construction cost calculator work?
It combines 2026 material and labor rates for your selected quality tier, adds typical permit costs and any options you choose, then applies a cost multiplier for your state. Adjust the inputs to see your estimate update instantly.
Is this calculator free to use?
Yes. This detached garage construction cost calculator is free, requires no signup, and returns instant estimates.
Does the estimate include labor and permits?
Yes. Each estimate combines material and labor costs for your chosen quality tier plus typical permit fees. Your final price still depends on your specific scope and local contractor rates, so collect itemized quotes before budgeting.
How can I lower my detached garage construction cost?
Get engineering plans done once and use competitive bidding to get the best framing price. Having your own plans lets you get apples-to-apples bids from multiple framing contractors. Choose LP SmartSide over cedar or premium wood sidings. It looks similar, costs 40-60% less, and has better moisture resistance.
Free newsletter
Stay current on what renovations actually cost
Updates from CostToRenovate, when there is something worth sending. Free, no spam.