June 26, 2026 · The Vespy Team
CAM Caps: Cumulative, Non-Cumulative, and Compounding
The three variables that define a CAM cap, why cumulative caps favor landlords over long terms, and the ordering error that defeats the cap entirely.
Part of CAM Reconciliation: The Complete Guide for Commercial Landlords .
A CAM cap limits how much a tenant recoverable expense share can rise year over year. It is one of the most negotiated protections in a commercial lease and one of the easiest to apply incorrectly.
Three variables
Every cap is defined by three things, and leases vary on all of them:
- Rate — commonly 3% to 6%
- Reference — measured against the base year, or against the prior year actual billable amount
- Behavior — cumulative or non-cumulative, compounding or simple
Get any one wrong and the ceiling is wrong.
Non-cumulative
The cap resets each year. If expenses rise 2% under a 5% cap, the unused 3% is lost.
| Year | Increase | Ceiling | Billed |
|---|---|---|---|
| 2 | 2% | 5% | 2% |
| 3 | 7% | 5% | 5% |
| 4 | 3% | 5% | 3% |
Simple, predictable, and the version tenants prefer.
Cumulative
Unused headroom carries forward. After a 2% year under a 5% cap, the following year can absorb the unused 3%:
| Year | Increase | Ceiling | Billed | Banked |
|---|---|---|---|---|
| 2 | 2% | 5% | 2% | 3% |
| 3 | 7% | 8% | 7% | 0% |
| 4 | 3% | 5% | 3% | 2% |
In year 3, the cumulative cap allows the full 7% where a non-cumulative cap would have limited it to 5%.
Over a long term, cumulative caps materially favor the landlord, because low-inflation years bank capacity that high-inflation years then use. In a decade with mostly low inflation and one spike, a cumulative cap can end up providing almost no protection at exactly the moment protection mattered.
Compounding
A compounding cap applies the rate to the escalated prior ceiling rather than the original base. Under a 5% compounding cap, the year-3 ceiling is the year-2 ceiling times 1.05, not the base times 1.10.
Compounding and cumulative are independent, and a lease can be both. A cumulative compounding cap is the landlord-friendliest common formulation.
What gets capped
Caps almost always apply only to controllable expenses — janitorial, landscaping, management, security, repairs. They almost never apply to property taxes, insurance, or utilities, because a landlord cannot control a tax reassessment or a utility rate increase.
This is normally implemented by splitting costs into separate recovery pools, each with its own cap setting. A lease that caps “operating expenses” without distinguishing controllable from non-controllable is ambiguous, and the ambiguity surfaces the first year taxes jump.
The ordering error
The cap is tested after the base year deduction. Not before.
Testing the cap against the full tenant share rather than the post-base-year amount produces a much higher ceiling and lets through increases the lease does not permit.
Worked through: a tenant share of $34,142 with a $9,180 base-year deduction leaves $24,962. A 5% cap over a $9,180 base-year reference gives a ceiling of $9,639 — so the cap binds hard. Test the cap first against the full $34,142 and the ceiling never binds at all, and the tenant is overbilled by roughly $15,000.
That error is invisible in a spreadsheet because nothing records which order was used. It is the strongest practical argument for a retained calculation trace.
Test cap behavior against your own figures in the CAM reconciliation calculator.