Garage doors are simply measured and estimated based upon the count, so to estimate your garage doors you simply need to count the # of doors you need to replace in the property.
A Garage Door Contractor can typically replace an existing garage door within 4 to 6 hours.
Garage door contractors will generally provide an all inclusive bid to 'furnish and install' all labor and garage door materials on the project.
Here is an example of how to write a Scope of Work that insures your Roofing Contractor provides an all-inclusive bid.
All Garage Door work is to be Contractor Purchased, Contractor Installed.