From a structural standpoint it is fairly easy to reduce the size of the opening in a garage thus creating the need for a smaller garage door.
Should openig be same size as garage door.
For instance if the width of the garage door is 8ft the rough opening should be 8ft 3 inches wide.
Single garage door openers generally do fine with smaller openers while double doors may need a little more horsepower.
However it is quite rare for anyone to want to do this.
Once again it should be obvious that if you have an arched opening the height would be the same as the highest point of the arch.
If it s 9ft the opening must be 9ft 3 inches and so on.
Entry doors are usually 36 inches wide.
While a door width of 36 inches is oversized for an interior door it s the standard size for front doors the standard height remains the same however.
Doors larger than this are considered double car garage doors.
This way the door will have a nice tight seal once the weatherseal or door stop molding is applied.
Doors that are 10 feet wide by 8 feet tall are single car garage doors.
As i stated earlier you will want the finished opening to be the same size or slightly smaller than the door.
Much more often homeowners seek to increase the garage door size to match vehicles that don t easily fit through the existing opening.
Measure the width and height of your garage door with a tape measure so you know what you have.
The width of the rough opening should be 3 inches greater than the width of the garage door you are purchasing.