The easiest way to understand what the Reserve Sense Benchmark Method is doing is to walk through a single component from start to finish.
The example
Assume a property has a fitness room with equipment that is expected to be replaced after 10 years.
For this example, we are looking at the component 2 years into its 10-year lifespan, with these assumptions:
- Component: Fitness Equipment
- Lifespan: 10 years
- Effective Age: 2 years
- Future Replacement Cost: $10,000
- Interest Rate: 2.9%
- CPI Inflation: 1.9%
The Benchmark Analysis asks two questions:
- How much money should already be in the reserve fund today for this component?
- If the reserve fund were at that fair level, how much should the property contribute this year for this component?
We will answer those questions in three steps. For simplicity, the dollar values below are rounded to the nearest dollar.
Step 1: Start with the basic idea
Ignore interest and inflation for a moment.
If the equipment will cost $10,000 to replace, and that cost is meant to be spread evenly over its 10-year lifespan, the simplest answer is:
- $1,000 per year
- for 10 years
If the equipment is already 2 years into its 10-year life, then the property should have accumulated about two years' worth of ideal funding by now. On this simplified basis, the property should contribute:
- Ideal Contribution: $1,000
And the property should have already saved:
- Ideal Balance: $2,000
That is the core idea behind the Reserve Sense Benchmark Method: each year, the owners fund an equal share of the equipment's replacement cost over its lifespan.
Step 2: Add interest
Real reserve funds do not just sit idle. If money is held in the fund before it is spent, we want to model investment income.
If the reserve fund earns 2.9% interest, then owners do not need to contribute the full $1,000 every year, because part of the replacement cost will be covered by interest earned on the balance already in the fund.
In this example, adding 2.9% interest changes our values to approximately:
- Ideal Contribution: $876 for each year of the component's life
- Ideal Balance: $1,778
In other words, once interest is recognized:
- the contribution needed this year becomes lower, and
- the target balance today becomes lower.
That is not because the component got cheaper; it is because part of the funding work is now being done by investment income instead of owner contributions.
Step 3: Add inflation
Now add one more real-world factor: inflation.
Even if $876 per year gets us to $10,000 after 10 years, it would still not be truly fair to keep every year's contribution identical. Money changes value over time. A dollar contributed earlier is usually worth more, in purchasing-power terms, than a dollar contributed later. So if every year's owners pay exactly the same nominal amount, earlier owners may end up carrying more of the real burden.
To correct for that, the Reserve Sense Benchmark Method lets contributions rise over time with CPI inflation.
This does not mean the component cost is assumed to inflate with CPI. Component costs are still projected using construction inflation (a separate rate). CPI is used here for a different reason: to keep the contribution pattern fair in real terms over time.
Once CPI inflation is added, after two years the values are:
- Ideal Contribution: $839
- Ideal Balance: $1,654
So once both interest and inflation are recognized, the method no longer targets flat dollar contributions. It targets contributions that remain fair in purchasing-power terms over time.
At that point, the method is doing what it is meant to do:
- spreading the replacement cost fairly over the component’s life,
- recognizing investment income, and
- keeping contributions level in purchasing power over time.
What the answers mean
For this component, the Benchmark now gives two practical answers for the current year:
- Ideal Contribution for this year: $839
- Ideal Balance: $1,654
Those are not arbitrary figures. They are the result of asking:
If this component’s cost were being funded fairly and consistently over its life, where should the reserve fund be today, and what should this year’s contribution be?
That is the heart of the method.
Why this example matters
This page only looks at one component.
A real reserve fund study does the same kind of calculation for each component separately, because each one has its own cost, lifespan, and age. Once those benchmark values are calculated component by component, they can be combined into the property-wide benchmark for the year.
So this example is small, but the logic is the same as the full method.
What Reserve Sense changes
The important point is that Reserve Sense is not changing the goal of Benchmark funding.
The goal is still to identify the reserve fund position that would be fair under the study’s assumptions. What Reserve Sense changes is the implementation: the method is carried through consistently, using interest and inflation logic that ensures the ideal funding path is fair and accurate.
Where to go next
This page keeps the example simple on purpose.
- Go to Formula Reference for the exact formulas and variables.
- Go to Modeling Assumptions for the timing rules behind the method.
- Go to Legacy Method: A Simple Check to follow one component and see where the commonly used Legacy Method breaks down.