These two terms can seem interchangeable to first time home buyers.
As a home buyer, you’re probably going to encounter terms like life expectancy and service life when you read your home inspection. The home inspector is going to be looking at various systems and appliances inside the home you’re about to buy and they’re going to tell you, perhaps, the age of those systems and appliances, along with how long they may last. But they’re going to use these terms, and the implication is different, so we want to make sure that up here, you understand that difference.
So, we’ll first talk about life expectancy. Life expectancy is, roughly, the estimate of how long something will last, period, before it fails. You can usually attach the term “life expectancy” to things like the roof of a house. And depending on the roof covering, that could be anywhere from 20-30 years. Or, another thing that might have a “life expectancy” would be the home’s windows. Depending on the make of the windows and the materials, those could also have a life expectancy, but a little bit less than a roof, of somewhere from 10-20 years.
Now you might be thinking to yourself, “ok, so what’s the difference between service life and life expectancy?”. Well, service life usually refers to things that are more mechanical. These are called envelope systems, service life is things that are more mechanical, like your HVAC. That’s the condensing unit that’s outside your house. Or your water heater, right? Service life means how long this particular appliance may function normally before it needs repair, or before it needs service. A condensing unit outside a home could be anywhere from 10-15 years and a water heater would be anywhere from 8 to 10 or more. It really all depends, and the reason why service life all really depends is because of parts. The availability of components that service or repair these things might be out of stock or discontinued after this many years. This does not mean these things are going to break, it doesn’t mean they’re going to function any less than 100%, even as they approach here, it just means that this is roughly the amount of time it’s going to take before it starts needing repair.