It is wise for buyers to factor in replacement costs for aging components when making an offer.  Replacing a home's windows, appliances or roofing can be pricey.   A new study by the National Association of Home Builders proves some insight that can help estimate the average useful life of household appliances and building materials.  The true longevity of any household material depends on the maintenance, use, quality of installation, and climate conditions.  100 Years or More: Brick siding:  Lifetime of the home,  Wooden Floors: Lifetime of the home,  Cellulose Insulation Material:  100 years plus. 50 - 100 Years Slate, copper and clay and concrete roofs:  50+ years, Copper Gutters:  50+ years,  Kitchen Cabinets:  50+ years,  Modified arcrylic kitchen sinks:  50 years,  Vinyl floors:  50 years. 30 - 50 Years Thermostat: 35 years,  Wooden Windows:  30 years, Wood shake roofs:  30 years, French Interor Doors:  30-50 years. 10 - 20 Years Built-in Audio System:  20 Years, Aluminum windows:  15-20 years, Asphalt Shingle Roofs: 20 years, Faucets, kitchen sinks:  15 years, Gas ranges: 15 years, Cultured marble countertops: 20 years,  Dryers and refrigerators:  13 years, Air Conditioning Units:  10-15 years, Lighting Controls: 10 years, Interior and exterior paint: 15 + years, Electric or gas water heater: 10 years, Air conditioners: 10-15 years, Furnaces: 15-20 years. 5 - 10 years: Security System: 5-10 years, Heat and smoke detectors: 5-10 years, Dishwasher: 9 years, Microwave ovens: 9 years, Carpet: 8-10 years. a