The majority of the companies charge by the square foot. Some companies charge by the square foot and also include a 10% waste charge in there price. There is a waste factor to every job. Rolls of turf come in 15 foot widths by any length, normally 50 or 65 foot lengths. You will always end up with smaller pieces (scrap) that normally cannot be used again.
Southwest Greens does not charge for a waste factor. Southwest Greens only charges for the actual square footage that was installed!