Cumulative vs. non-cumulative CAM caps: a worked comparison

A CAM cap limits the expenses identified by its wording. “Cumulative,” “non-cumulative,” and “compounded” can describe different features, so the label alone is not a formula. Write out the permitted calculation, identify the expense categories it covers, and test it across several years before comparing lease offers.

The examples below define two hypothetical formulas. They are arithmetic illustrations, not claims that every lease uses these meanings or that a particular increase is enforceable.

Define the covered expense pool first

List the costs inside the cap and those outside it. If the lease caps only controllable expenses, identify how it defines controllable and what it excludes. Then identify the initial dollar base, the annual percentage, the measurement period, and how any unused capacity is treated.

A $100,000 cap calculation applied to a building expense pool is different from the same calculation applied to one tenant's bill. Confirm whether the cap applies before or after allocation, and how the relevant area or share is calculated.

Formula A: a ceiling compounded from the original base

Assume a hypothetical $100,000 starting covered-expense base and an annual ceiling equal to that original base multiplied by 1.05 for each elapsed year. The first-year ceiling is $105,000. The second-year ceiling is $110,250, even if the actual first-year covered expense is only $102,000.

Under this defined formula, a second-year actual expense of $112,000 would be limited to $110,250 before any other adjustments. The ceiling grew independently of the prior year's actual bill.

This example illustrates a base-driven compounded ceiling. A lease may use different language or add a separate carry-forward mechanism; that needs its own calculation.

Formula B: a ceiling based on the prior year's allowed expense

Now assume a different hypothetical formula: each year's covered charge cannot exceed 105% of the preceding year's allowed covered expense, and there is no separate carry-forward of unused increases.

With the same $100,000 start and $102,000 actual first-year covered expense, the first-year allowed amount is $102,000. The second-year ceiling is $102,000 × 1.05 = $107,100. At the same second-year actual expense of $112,000, the allowed amount would be $107,100.

The two defined formulas produce a $3,150 difference in year two: $110,250 minus $107,100. The difference comes from the baseline used for the increase, not a change in the stated 5% rate.

A cap may not cap the whole bill

Suppose a hypothetical tenant's covered charge is $20,000, increasing to $21,000 under a 5% cap. Separately, uncapped charges increase from $10,000 to $13,000. The combined bill rises from $30,000 to $34,000, or about 13.3%.

That does not by itself prove a cap violation. The review must determine whether the supposedly uncapped categories are actually excluded by the signed language and whether the amounts and allocation are supported.

Copy these questions into the review

• What exact dollar amount or prior-year figure forms the base?
• Is the ceiling compounded, and from which date?
• Does unused capacity carry forward, and is that mechanism defined?
• Which categories are excluded from the cap?
• Is the cap applied before or after allocation and other adjustments?
• What happens when an expense falls and then rises?
• Where are the records supporting each input?

Use the operating expense cap definition for terminology and the CAM reconciliation review guide for reviewing an actual statement. Ask counsel or a qualified lease auditor to resolve ambiguous formulas before disputing a charge.