The Cost of Upkeep

These days, people move so often that it can be tempting to defer maintenance, since you may not be around when the furnace blows. But this can come back to haunt you if the buyer has the home inspected: Any problems that show up in the report can be used to negotiate the price down. Lesh says sellers are often incredulous at the results. "People think, 'What are you saying? My furnace works great.' But because it's rusty, because you didn't clean it, it's showing signs of premature wear."

In some cases, a little bit of maintenance can go a long way toward preventing major problems down the road. For example, tree limbs that hang over the roof may sag and rub against the shingles when it rains or snows. They can also provide easy access to your home for pests like squirrels and mice. Simply trimming the branches will reduce a lot of wear and tear.

"Sometimes the life of a component can vary from 15 to 25 years," Lesh says. "There are lots of reasons, such as climate, but you can have the same type of furnace in two houses on the same block and one will last 15 years and the other 25 -- and it's because of maintenance."