How much does it cost to build a detached garage?
For this discussion we will assess the costs of building detached a two-car as well as a four car garage. The measurements of the average two car model is 26'x26'or 676 square feet. The average square footage of a four car garage is 48'x30' or 1440 square feet. Both easily accommodate vehicles, but also provide ample room for storage and even a small work area.
Building either of these garages would not be considered any sort of "DIY" project, and professional contractors will be necessary for the job.
For the building of the garages, the typical costs will include:
- Two car - According to Hanley Wood and their "Remodeling" magazine, the cost to construct a standard two-car garage addition is $58,432. This translates to $86 per square foot; and
- Four car - Traditionally, the per square foot costs on larger structures will decrease, and it is safe to assume a $60 per square foot cost on the larger unit. This translates to a total cost of $86,400.
What needs to be included:
- Excavation and site preparation - The average costs are going to vary according to the level of work necessary;
- Concrete footings 1 and slab "to grade" - The average price of concrete is $75 per cubic yard, with the full slab it that would require roughly 13 cubic yards for the two car version at a cost of $975, while it would take 27 cubic yards for the four car version at a cost of $2025;
- Roof trusses 2 and a support beam system - lumber prices vary according to the design used in constructing the garage. The project should require 2x4 wood framing, OSB structural sheathing, and a roof at 6/12 pitch;
- Asphalt 3 shingles 4 with galvanized flashing 5 - this will cost an average of $80 to $100 per square of 50-year shingles 4 (which cover around 100 square feet). The two car garage would have a total of 728 square feet for a cost of $700, and the four car garage would have a total of 1728 square feet at a cost of $1700 - both sets of prices are for materials only;
- Vinyl 6 siding and trim - Average price of $7 per square foot installed, and for the two car garage would need 1040 square feet at a cost of $7200, and for the four car garage it would take 1560 square feet at a cost of $10920;
- Double-hung 30-by-48-inch vinyl 6 windows - Average price of $300-$700 per window;
- Install 3'x6'8" exterior doors with half-glass and locksets - Average of $250 to $1000 each;
- Electrical wiring and exterior lighting to code - This is going to depend upon the amount of work required, and must include a 100-amp breaker and an independent panel. Electricians average from $65 to $85 per hour. This project might be priced on a per item basis, or the electrician might simply base it on the square footage.