Life Expectancy of Major Home Systems

In the course of buying a home, home buyers are often interested in knowing the general life expectancy for some of the major systems and components of their new home. All systems and components can have a wide range of useful life depending upon the design and initial installation as well as how the system or component is maintained once installed. Age is not a defect, but when looking at homes, keeping an eye out for the approximate remaining life of the home’s major components is wise in terms of budgeting for the future and having reasonable expectations.

Keep in mind that determining the life expectancy and remaining life of any system/component is outside the scope of a home inspection, although most home inspectors will include the general life expectancies for most major systems as part of their report as a courtesy for their clients.

Roofing –

Most modern homes in PA have asphalt shingled roofs. While 15 and 20 year shingles were the norm 30 years ago, most shingles installed on newer homes, and even reroofs, tend to be 25 year shingles, minimum. 20 year shingles are still available but aren’t found terribly often anymore on new installations. Modern flat 3-tab shingles are 20 year or higher rated, yet when you see architectural (also called “dimensional”) shingles you can be safe to assume these are, minimum, 25 year shingles. The actual life you may achieve from asphalt shingles can vary considerably based upon the weather and sunlight exposure the roof gets throughout its life as well as whether the roof/attic has adequate ventilation.

The above life expectations are based upon a single shingle layer. Some roofers will install a 2^nd shingle layer over an older layer; doing so will save on installation costs since the original layer isn’t removed, however the new 2^nd layer may only actually last half of its design life. In other words, having a 30 year shingle installed over your original worn 1^st layer may result in this new 30 year shingle lasting, maybe, only 15 years. Homeowners need to be very aware of this fact when it comes time to get roof replacement quotes. Paying extra for a 30 or 40 year shingle can easily be a waste of money when installing it as a 2^nd layer. Removal of the 1^st layer and installing a fresh new single layer of shingles is normally best. Read my Common Roof Types article.

Central Heating/Air Conditioning (HVAC) Equipment –

Most homes in our area have either gas or oil fired furnaces or boilers. Remember, furnaces heat air whereas boilers heat water. These terms (“furnace” and “boiler”) are not interchangeable and Realtors and home buyers/sellers need to know the difference. Assuming regular maintenance, such as an annual professional clean/service and changing their air filters regularly, most furnaces should last approx. 15~20 years. Improperly maintained systems may only last 12~15 years. Boilers are generally 1 of 2 varieties: steel or cast iron. A steel boiler generally has an approx. 20 year life expectancy whereas a cast iron boiler can exceed 40 years.

Central air conditioning (A/C) and heat pump systems also should be professionally serviced annually and their air filters replaced regularly. Furnaces, heat pumps, and A/C systems rely on specific amounts of air flow through them for proper operation; dirty air filters for a prolonged time can subtract life off of these systems leading to early failure. Generally, central A/C systems last between 15~20 years whereas heat pump systems last approx. 15 years.

Something to keep in mind if you have a pre-2006 A/C or heat pump system. These systems generally use Freon® (R-22) as their refrigerant. This refrigerant is being phased out by the Federal government so it will no longer be available in the year 2020 and beyond. Just for that reason, budgeting for replacement would be wise. Newer A/C systems and heat pump use Puron® (R-410a) instead of Freon® although even Puron is on its way out with newer HVAC equipment coming onto the market now.

Read my Energy Saving Cooling Tips article.

Read my Energy Saving Heating Tips article.

Water Heaters –

Due to the high mineral content of south-central PA water, it tends to be moderately or very hard whether you have a well or public water. Most local public water systems get their water from deep wells. An approximate life expectancy for tank-style water heaters is about 8~12 years, although homes with very hard water, no water softener, and their tanks don’t get regularly drained, may only last about 5 years. I have occasionally found water heaters exceeding 25 years in my home inspection travels but that is often in a home with a water softener and maybe a single person living in the home. The more use the water heater gets, generally the shorter its life.

Tankless water heaters have become more popular in the USA in the past 10~15 years. They have been used in Asia and Europe a bit longer than that. The general design life of a tankless water heater is 20+ years. These systems should be flushed annually according to their manufacturers, especially in our area due to our hard water. Not doing so can void the manufacturer’s warranty. Read my Tankless Water Heater’s article.

Major Kitchen Appliances –

Most kitchen appliances, such as ovens and refrigerators, have approx. life expectancies of about 20 years. Dishwashers and garbage disposals are sometimes half of that; this is commonly due to usage. Garbage disposals that have a lot of water passing through them (such as a single kitchen sink so all water passes through the disposal on the way to the sink’s drain) often fail early. We have likely all seen a few refrigerators and dishwashers that are well over 30 years, but this is rare. Read my Appliance Maintenance Tips article.

Siding Materials –

Most homes in our area are covered with vinyl siding. The siding’s color can fade over time (especially when starting as a darker color) but vinyl siding should easily last 30+ years. In some cases, it gets damaged (such as cracked) by being hit with something or even by using a weed trimmer at its bottom. Vinyl siding has been common since the late 1980s and early 1990s.

Brick is very common in older homes (from the 1800s [and before] and first half of the 1900s) and can easily last more than 100+ years. Brick and stone need to be regularly inspected and maintained (such as tuck pointed) by a qualified mason. Brick can spall, however most of the exterior wear for brick homes is in the mortar. Spalling is when the brick deteriorates from the inside out, often due to freeze/thaw damage. Mortar can crack or deteriorate enough to fall out; repointing replaces the affected mortar joints in order to give support to the adjacent bricks as well as minimize water or insect entry.

More Information-

Read my companion article Appliance Maintenance Tips. Also, the Association of Home Appliance Manufacturers provides additional information about home appliances, safety standards, energy efficiency, and more for consumers.

Matthew Steger is a Certified Level 1 Infrared Thermographer, an ASHI Certified Inspector (ACI), and an electrical engineer. He can be reached at matthew@thehomeinspectorsnotebook.com. No article, or portion thereof, may be reproduced or copied without prior written consent of Matthew Steger.