Estimating Garage Construction Costs

Determining the cost of your new garage ahead of time allows you to budget appropriately and secure the necessary funds. Estimating garage construction costs is something you can do yourself. Knowing what you need in advance can also give you some leverage when negotiating with local contractors and building suppliers.

Groundwork

Survey the site with your contractor to determine how much preparation is needed before the building of your new garage begins.

Frame

Measure the length and width of your building. Using the standard layout of 16 on center, convert feet to inches and divide that by 16. Throw in about 20 extra sticks for window and door openings, bracing and blocking. Add one pressure treated 2-by-4 to go around the bottom, between the concrete and the sill. Add two standard 2-by-4s to go around the perimeter of the wall.

Roof

Measure the length of your building. Convert that to inches. Divide the inches by 16 to determine the number of rafters needed. Determine the roof pitch in order to figure out rafter length.  Add a double ridge poll. Using the standard 4-by-8 sheathing measurement, determine how many sheets of plywood are needed.

Shingles

Measure the length and width of the roof and divide that by 10. Multiply that number by 2 and that will give you how many square feet of shingles are needed to cover your roof.

Siding

Determine the amount of siding needed. The amount of siding needed depends on the type of exterior siding chosen. If using T-111 you would use the standard 4-by-8 measurement to determine the quantity needed. If a different type of siding, first measure the walls. Next multiply length by height and divide that number by 10 to figure out how many square of siding you need per wall.

Doors and Windows

Remember to add the costs of your doors and windows along with any extras features you wish to add to your new garage.