When you decide it's time to consider a new roof, consider first your budget and your goals. Metal roofs tend to last longer than asphalt shingles, but they cost more upfront and may not "fit in" with the neighborhood. Asphalt shingles are an affordable option, but even in that arena, there are choices that will determine the overall aesthetic and potential lifespan of the roof. Consulting a roofing contractor to help you make these choices is best. They'll have the experience to help guide you towards the best result.