Cost is a very important factor when deciding on a residential roof system replacement versus a residential roof repair. Most building owners look at building maintenance expense as something that can be expressed and evaluated over time (in cost per year). In order to determine cost per year, you must know (approximately) how long something will last. For this example, let’s say a new roof system will cost $50,000 and has a projected lifespan of 25 years. Now let’s say that it will cost $14,000 to repair the same roof and the projected lifespan of the repair is 7 years. Not factoring inflation into the calculation, both scenarios will yield exactly the same cost of $2,000 per year. In this example, the option requiring the least amount of capital would most likely be desirable. This simple equation can help building owners determine which option will produce the lowest cost per year and will usually help them decide which option makes the most sense for their unique situation.