Your kitchen faucets can be expected to last 15 years while your toilets can last the life of your house (though the mechanism inside the tank will require occasional maintenance) according to a study of home components recently conducted by the National Association of Home Builders and sponsored by Bank of America Home Equity.

The study, conducted among experts in a wide range of fields, points out that the life expectancies it reports are averages that are affected by many factors such as usage patterns, climate, advances in technology and consumer preferences that cause change of components with useful life left in them. The study also indicates that the life expectancies of housing components are greatly affected by quality of maintenance.

Some of the components with shortest life spans are humidifiers and dehumidifiers (eight years) and dishwashers (nine years).

Among the longest lived are soapstone sinks (100+ years). Bathroom shower doors can be good for 20 years and whirlpool tubs for 20 to 50 years (depending on use) while bathroom shower enclosures can be expected to be good for 50 years and showerheads for a lifetime.

Looking at HVAC systems, the study says that they require “proper and regular” maintenance to work efficiently; in the best of scenarios, most HVAC components will last 15 to 25 years. Furnaces are good for 15 to 20 years on average, heat pumps for 16 years, and air conditioning units for 10 to 15 years. Tankless water heaters are expected to last more than 20 years according to the experts while electric and gas water heaters have a life expectancy of 10 years. And though thermostats have an average expected life span of 35 years, says the study, they usually are replaced sooner due to technological improvements.