Here in the loft we actually don't refer to the life of a sail in years but rather in seasons. For example, the main sailing season in Annapolis can begin in the early spring and extend late into the fall, but we would consider that a season of life for your sail. Now, if those same sails that have spent the sailing season furled on your headstay or in your mast or boom are left to endure the frigid months of winter in the sun, rain and snow, then you have "spent" another season of that sail’s life.
Another thing to consider in this equation is downtime during the sailing season; if you know that your sails are going to be left sitting idle on the boat in a marina for at least a month during a sailing season, why not try to save that month of the sail’s life by taking the sails off of your boat and stowing them?
If this seems like too big of a job or if you realize that this is the case only after driving the couple of hours home, our service department would be glad to go to your yacht, take the sails off, and bring them back for an inspection or storage here at the loft.