It’s not just the cost, it’s the upkeep. That old saw holds true in homebuying and maintenance. Repair and replacement costs mount each decade of a home’s life, and each generation of homes has its own frailties. Understanding home life cycles is key to making informed buying and remodeling decisions. Census data put the median age of

U.S. homes at 32 years. Wood decks, garage doors, faucets and some appliances start showing their age at 10 to 15 years or even earlier. Other parts of a home — such as wood floors, some kinds of doors, insulation, fiberglass and toilets — can last more than 35 years or the life of a house, according to a National Association of Home Builders study. These are only averages, however. To find out how a particular home is aging, and whether its diet and exercise regimen (repair and maintenance plan) is working, homebuyers can turn to experts. An experienced home inspector can alert them to looming repair needs and a timeline for ongoing maintenance. Learn What You Have A general inspection of the entire home should be the first order of business for buyers, says Max Curtis, a home inspector working in the

East San Francisco Bay area. “We’re kind of the general practitioner,” he said. “If we see problems, we may send them to a specialist.” Waterworks woes might warrant calling in a plumbing inspector, for example. Costs for comprehensive inspections vary around the country. Curtis says he charges $200 to $250 for what’s typically a three- or four-hour visit. He advises buyers to get an inspection even if the house is new or almost new. It’s important because shoddy construction or installation issues can cause unexpected problems down the road. The expected issues are enough to cope with. Here’s a rundown on how long home components last: Eight to 10 years: Some appliances age rapidly, the NAHB study found. Trash compactors have the shortest average life span at just six years. Small refrigerators and humidifiers also have a relatively short life span at eight years on average, followed by dishwashers and microwave ovens at nine years. Out in the real world, remodeling contractors and inspectors say they see problems with thermal pane windows, sometimes in a home’s first decade. Fogging between the panes is the most common issue, Curtis says. “It’s almost routine,” he said, and “hard to pick up because they change hourly.” Eleven to 20 years: In this age group, homeowners can expect to replace some appliances and they’ll want to look closely at the roof and any wood decks or balconies, paint and siding. Also, lighting and electrical panels should be evaluated. Even buyers of younger homes are adding home theaters, spa tubs and smart-home features (lighting, heat and other controls), and these usually require updating the electrical system, says Greg Johnson, co-owner of remodeling firm Lee Kimball in

Winchester, Mass. Twenty to 35 years-plus: At 20 years and older, the roof needs a thorough inspection and probably some work, if not replacement. Whole house systems — plumbing (including faucets), electrical, heating and venting — need to be inspected and maybe updated. The furnace could need replacement, and some flooring (carpets, vinyl, wood floors) likewise. Homes built in the 1950s usually need wiring and plumbing updates, says Scott Gregor, president of Master Plan Remodeling in

Portland, Ore. One electrical panel used in the 1950s and ’60s, Federal Pacific Brand, was faulty; John Fryer, a home inspector in

Berkeley, Calif., says to replace it when found in a home. Exterior Insulation Finish Systems’ (EIFS) stucco is a synthetic stucco that leaks if not properly sealed and installed, says Fryer. Curtis says synthetic shake roofs need to be looked at closely — failures of these roofs have led to many lawsuits. Also, in the mid-1980s some plumbers used defective ABS pipe, Curtis says. Root Of Big Problems One very costly issue with homes 15 years and older is trouble with sewer lateral lines, which connect homes to the public sewer system. In Northern California, problems have been so prevalent that nine cities now require a sewer pipe certification when homes 15 to 25 years and older are sold, says Pamela Vivion-Brooks, co-owner of Pipe Cams in

Livermore, Calif. She says even newer sewer lines in areas with many trees should get inspections. In Arizona, older homes have cast-iron sewer lines now needing replacement, says Rocky Dunn, owner of Greenwood Contracting in

Phoenix.

Some problems are due to pipe degradation. In

California, older pipes of clay and Orangeburg (wood fiber with pitch) are the troublemakers. But overall, 59% of problems are tree-root related, says Vivion-Brooks. Trees can start messing with pipes after just a few years, especially with newer ABS pipe that hasn’t been properly glued.

Kathleen Doler