GARAGE
How to Estimate a Detached Garage
Contractor method for estimating a detached garage: area, finish, doors and electrical.
Detached garage bids fail on the finish and the electrical run. The area is easy math; masonry, wood and metal kits are very different rates, and the electrical run from the house grows the quote.
THE SHORT ANSWER
How do you estimate a detached garage?
Measure the area, choose the finish (masonry $55, wood $30, metal kit $25/sq ft), then add doors (~$1,854 each) and electrical (~$1,200). A 400 sq ft masonry garage with 1 door runs about $25,054.
Measure the footprint
Measure the garage area in sq ft and note the site. A standard 2-car is ~20×20 ft (400 sq ft). Confirm the slab and site prep before quoting.
- Measure the footprint
- Check the site and grading
- Note frost depth and soil
- Confirm the distance from the house
Pick the finish
A masonry garage runs ~$55/sq ft, wood ~$30 and a metal kit ~$25. Masonry is durable and pricey; metal kits are the cheapest.
Price doors and electrical
Each garage door adds ~$1,854 and the electrical run ~$1,200. The run from the main panel to a detached garage can add significantly. Use the Detached Garage Cost Calculator.
Check the total
Your total should land within 10% of the calculator output before markup. Confirm the permit and set-back before you quote.