Nothing in life lasts forever – and the same can be said for your home. From the roof to the furnace, every component of your home has a lifespan, so it’s a good idea to know approximately how many years of service you can expect from them. This information can help when buying or selling your home, budgeting for improvements, and deciding between repairing or replacing when problems arise.

According to a National Association of Home Builders (NAHB) study, the average life expectancy of some home components has decreased over the past few decades.  (This might explain why you’re on your third washing machine while Grandma still has the same indestructible model you remember from childhood.) But the good news is the lifespan of many other items has actually increased in recent years.

Here’s a look at the average life spans of some common home components (courtesy of NAHB).

Appliances. Of all home components, appliances have the widest variation in life spans. These are averages for all brands and models and may represent the point which replacing is more cost-effective than repairing. Among major appliances, gas ranges have the longest life expectancy, at about 15 years. Electric ranges, standard-size refrigerators, and clothes dryers last about 13 years, while garbage disposals grind away for about 10 years. Dishwashers, microwave ovens, and mini-refrigerators can all be expected to last about nine years. For furnaces, expect a lifespan of about 15 years for electric, 18 for gas, and 20 for oil-burning models. Central air-conditioning systems generally beat the heat for 10 to 15 years.

Kitchen & Bath. Countertops of wood, tile, and natural stone will last a lifetime, while cultured marble will last about 20 years. The lifespan of laminate countertops depends greatly on the use and can be 20 years or longer. Kitchen faucets generally last about 15 years.  An enamel-coated steel sink will last five to 10 years; stainless will last at least 30 years; and slate, granite, soapstone, and copper should endure 100 years or longer. Toilets, on average, can serve at least 50 years (parts such as the flush assembly and seat will likely need replacing), and bathroom faucets tend to last about 20 years.

Flooring. Natural flooring materials provide longevity as well as beauty: Wood, marble, slate, and granite should all last 100 years or longer, and tile, 74 to 100 years. Laminate products will survive 15 to 25 years, linoleum about 25 years, and vinyl should endure for about 50 years. Carpet will last eight to 10 years on average, depending on use and maintenance.

Siding, Roofing, Windows. Brick siding normally lasts 100 years or longer, aluminum siding about 80 years, and stucco about 25 years. The lifespan of wood siding varies dramatically – anywhere from 10 to 100 years – depending on the climate and level of maintenance. For roofs, slate or tile will last about 50 years, wood shingles can endure 25 to 30 years, the metal will last about 25 years, and asphalts got you covered for about 20 years. Unclad wood windows will last 30 years or longer, aluminum will last 15 to 20 years, and vinyl windows should keep their seals for 15 to 20 years.

Of course, none of these averages matter if you have a roof that was improperly installed or a dishwasher that was a lemon right off the assembly line. In these cases, early replacement may be the best choice. Conversely, many household components will last longer than you need them to, as we often replace fully functional items for cosmetic reasons, out of a desire for more modern features, or as a part of a quest to be more energy efficient.

Are extended warranties warranted?

Extended warranties, also known as service contracts or service agreements, are sold for all types of household items, from appliances to electronics. They cover service calls and repairs for a specified time beyond the manufacturer’s standard warranty. Essentially, warranty providers (manufacturers, retailers, and outside companies) are betting that a product will be problem-free in the first years of operation, while the consumer who purchases a warranty is betting against reliability.

Warranty providers make a lot of money on extended warranties, and Consumers Union, which publishes Consumer Reports, advises against purchasing them.  You will have to consider whether the cost is worth it to you; for some, it brings a much-needed peace of mind when making such a large purchase. Also, consider if it the cost outweighs the value of the item; in some cases, it may be less expensive to just replace a broken appliance than pay for insurance or a warranty.