How to calculate CAM caps and exclusions
A practical walkthrough of controllable-expense caps and common CAM exclusions—the two lease terms that most often turn a reconciliation into a dispute.
Two lease terms cause more CAM disputes than any calculation error: a controllable-expense cap that wasn't applied correctly, and an exclusion that wasn't honored. Both are mechanical once you know exactly how to apply them—here's the math.
BEFORE YOU SEND THE STATEMENT
The reconciliation checklist and the calculator that goes with it.
Every record to gather and every lease rule to confirm, in order; then check one tenant’s number with a cap applied.
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Start with what's actually recoverable
Before caps or exclusions enter the picture, every CAM-eligible expense needs a yes-or-no answer: does the lease allow this category to be passed through to tenants at all? Anything that isn't recoverable goes to HOUSE—the owner's own cost, tracked but never billed.
Caps and exclusions only apply on top of that recoverable base. Getting the base wrong makes every downstream calculation wrong too, no matter how carefully the cap math is applied.
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What a controllable-expense cap actually limits
Most caps apply only to “controllable” expenses—landscaping, cleaning, general repairs, administrative fees—not to the whole CAM bill. Real estate taxes, insurance, utilities, and snow removal are usually carved out as “uncontrollable” and pass through in full, uncapped.
The logic is straightforward once you see it: a landlord has some ability to shop for a cheaper landscaping vendor, so a tenant can reasonably ask that category to be capped. A landlord has no ability to negotiate the county's tax assessment, so leases rarely try to cap it.
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Cumulative vs. non-cumulative caps—the math that trips people up
Lease drafters use different terms for this, but the two versions you'll run into most often work differently enough to change what a tenant owes by thousands of dollars over a term. Always go by how the lease itself defines the cap.
A cumulative cap (also called compounding) grows from a fixed starting point: the base-year amount, increased by the cap percentage every year and compounded, whatever was actually spent. This year's ceiling is last year's ceiling times (1 + the cap percentage), so room a cheap year didn't use carries forward. A non-cumulative cap measures each year's increase from what the tenant was actually billed the year before—so a year where actual expenses came in under the cap lowers the base for every year afterward.
Key points
- Cumulative (compounding): this year's cap = base-year amount × (1 + cap%) for each year since the base year, which is the same as last year's CAP × (1 + cap%)
- Non-cumulative: this year's cap = last year's BILLED controllable CAM (after the cap) × (1 + cap%)
- A cumulative cap is more predictable for the owner; a non-cumulative cap is more favorable to the tenant whenever actual spending runs below the cap
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Common exclusions, and why they each exist
Exclusions carve specific costs out of CAM even when the category would otherwise be recoverable. Most exist for a clear reason once you know it.
Key points
- Capital expenditures (roof, HVAC replacement, parking lot resurfacing)—often excluded entirely, or allowed only as an amortized portion over the item's useful life
- Leasing commissions and tenant-improvement costs—these benefit the owner's re-leasing effort, not the existing tenants
- An administrative or management fee cap—many leases cap the admin fee itself at a stated percentage of total CAM, separately from the controllable-expense cap
- Costs to cure a code violation that predates the lease—the owner's own pre-existing obligation, not a shared operating cost
- Fines or penalties from the owner's own negligence
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A worked example
Say a tenant's controllable share was capped at $11,400 last year, but actual spending came in at $11,000, so they were billed $11,000. The lease has a 5% cap, and this year's uncapped pro-rata share works out to $12,000.
Non-cumulative cap: this year's ceiling is last year's billed $11,000 × 1.05 = $11,550—lower than the $12,000 uncapped share, so the tenant owes $11,550, and the excess never gets billed or carried forward. Cumulative (compounding) cap: this year's ceiling is last year's $11,400 cap × 1.05 = $11,970—still below $12,000, so the tenant owes $11,970 instead. Same lease term, same year, a $420 difference, purely from which version of “cap” the lease actually specifies.
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What still needs a person
Whether a specific expense falls inside or outside an exclusion is sometimes a genuine judgment call—a repair that's really a capital improvement in disguise, for instance. Read the exact exclusion language, and when it's ambiguous, that's a conversation with an attorney or an experienced CAM consultant, not a formula.
FAQ
Frequently asked questions
Do caps apply to real estate taxes and insurance?
Usually not. Most commercial leases treat taxes, insurance, and sometimes utilities as uncontrollable and pass them through in full, reserving caps for categories the landlord has some ability to manage.
What happens if a cap was never applied in a prior year?
That depends on the lease and, often, on how the tenant relationship has gone—some owners correct it prospectively, others go back and true up prior years. There's no universal rule; review the lease's own audit and correction language.
Can a new exclusion be added after the lease is signed?
Not unilaterally. An exclusion is a negotiated lease term; changing it after signing needs a written amendment both parties agree to, not just an internal CAM-methodology decision.
Free template
Get the CAM reconciliation worksheet
The spreadsheet version: recoverable pool, each tenant's share, caps, proration, admin fee and the true-up balance. Comes with the reconciliation and audit checklists.
- CAM reconciliation worksheetSpreadsheet template
- CAM Reconciliation ChecklistPrintable checklist
- CAM Audit Checklist for Landlords and TenantsPrintable checklist
Put it into practice
TenantPoint handles this workflow in CAM reconciliation software and Commercial lease administration software. See all TenantPoint solutions or how it compares with other software.
This educational material is not legal, accounting, tax, or investment advice. Review controlling lease language and consult qualified professionals when appropriate.
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