Remaining useful life

What the number actually measures

Every component your association is responsible for, the roof, the clubhouse HVAC unit, the asphalt, carries its own remaining useful life estimate inside the physical analysis half of the study. The term has one specific meaning.

"the estimated time, in years, that a reserve component can be expected to serve its intended function"

Source: What's Included in a Reserve Study? Key Elements Explained, Reserve Advisors

A component with five years of remaining useful life is expected to keep working for five more years. A component with zero remaining useful life is due for replacement now, in the current budget cycle, not that it has already failed or dropped out of the study.

Remaining useful life, useful life, and effective age

Remaining useful life only makes sense next to two other numbers. Useful life is the component's total expected lifespan when new. Effective age is the portion of that lifespan already used up: useful life minus remaining useful life. A roof with a 20 year useful life and 5 years of remaining useful life has an effective age of 15 years, three quarters of its expected life already behind it.

Boards rarely see effective age spelled out on its own line in a study, but it is doing work behind the scenes. That same effective age is what feeds the study's fully funded balance calculation, the benchmark that percent funded is measured against.

Why the number changes at every update

Two reserve studies for the same association, done years apart, will show different remaining useful life numbers for the same component, even without a single new item added to the component inventory. That is expected. The inventory tends to stay stable from one study to the next, but the preparer walks the property again at each update and re-scores the actual condition of every component, then rebuilds the life and cost estimates on top of that fresh look. A roof rated at 8 years remaining two studies ago might sit at 4 years remaining now, or 6, depending on how it actually held up, not just on subtracting years from a calendar.

How often that reinspection is required varies by state. California requires an update at least every three years once major components pass a size threshold, and Nevada requires one at least every five years. Check your own state's statute and your governing documents for the cycle that applies to your association.