If you are installing a 9 wide door the opening will be 9 3 wide.
Making garage door wider.
Make sure you leave an inch to make the aligned properly.
Wall extensions because garage doors are usually sized to snugly fit the dimensions of the garage itself making the door larger usually means making the garage larger.
To make a door frame wider the do it yourself should also ensure that the planned construction does not cut into any existing electrical or heating and air conditioning equipment.
You re like going to need to remove 1 4 on the hinge side prior to gluing the additional stock.
Frame the rough opening to 3 inches wider than the garage door size you have selected.
Include motion sensor lighting with the garage door opener as well as on other lights in the garage.
For example eight feet tall with 4 feet wide are the best solution for one swing door.
Step 1 remove the existing door from the frame by unscrewing the screws on the hinges and lifting the door away.
Use a black marker to mark the new location for the side of the doorway along the interior of the existing wall.
Use an exterior glue if this will be an exterior door.
One way to do it would be to get wall extensions for the entire the garage and then cut the roof of the garage off lifting it up to the height you want it.
If you are widening the door because of a new vehicle widen the door to the equivalent of two additional feet per side of vehicle.
Install an electric overhead garage door opener with a remote control located at an accessible height for a seated person.
You can start to buy materials after making the plans such as proper lumbers rails and other carpenter stuff.
Here you should have the correct dimensions of your garage.
You also can base the new opening size on the width of the new door you purchase for the garage.
Skylights can provide additional day lighting as a safety factor.