When buildings sit at 30–40% occupancy, gross-up provisions can inflate every tenant's CAM bill by 2x or more. Post-pandemic office markets have created systematic gross-up abuse. Here is how to detect it.
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Find My OverchargesSee a sample report firstWhen a building hits 40% occupancy, gross-up provisions allow landlords to bill tenants as if it were 95% occupied. In 2024 and 2025 office markets averaging 19 to 22% vacancy nationally, this single provision can double a tenant's CAM bill compared to what the actual operating costs justify.
Gross-up is one of the most misunderstood provisions in commercial leases. When buildings operated at 90 to 95% occupancy, it rarely caused significant harm because the hypothetical full-occupancy number was close to reality. Post-pandemic, that assumption collapsed. Buildings sitting at 40%, 50%, or 60% occupancy are now billing tenants as if every square foot were leased and active, inflating variable expenses far beyond their real cost.
I built CAMAudit because this specific problem, gross-up abuse at high vacancy, generates some of the largest and most systematically hidden overcharges I have seen in the audit pipeline. The math is straightforward once you know where to look.
A gross-up provision allows a landlord to adjust (inflate) variable operating expenses to reflect what they would cost if the building were fully occupied, typically defined as 95% occupancy. The stated purpose is to protect tenants: if the building is only 50% occupied, the landlord argues that certain variable costs like janitorial and utilities would be higher per-occupied-square-foot at full occupancy, and the current low-occupancy number understates the "real" operating cost per tenant.
In practice, the provision works like this:
Your pro-rata share is then applied to the inflated $1,520,000 figure, not the actual $800,000. That $720,000 difference gets allocated to tenants who are actually in the building.
The 95% assumption is what makes this provision so dangerous. Almost no commercial market operates at 95% occupancy today. When the actual number is 40% and the gross-up targets 95%, the multiplier is 2.375x. A tenant expecting to pay their share of $100 of actual costs ends up paying their share of $237.50.
Gross-up is only legally defensible when applied to variable expenses, costs that actually scale with occupancy level. Utilities, janitorial, trash removal, and HVAC maintenance are genuinely variable. They cost more when more tenants occupy the building.
Fixed costs are the landlord's structural overhead regardless of occupancy: property taxes, insurance premiums, management fees calculated as a percentage of revenue, roof maintenance contracts, and capital improvement amortization. These costs do not change whether the building is 40% or 95% occupied.
Applying gross-up to fixed costs is indefensible, yet it happens routinely. A landlord who grosses up the entire CAM pool including fixed costs is inflating expenses that have no occupancy relationship. CAMAudit's Rule 5 checks each line item category against a fixed-versus-variable classification and flags gross-up applied to non-variable costs as a violation.
The 2020 to 2025 period created a structural vacancy crisis in office markets that has no modern precedent. Remote work adoption, lease expirations not renewed, and corporate footprint reduction drove vacancy to levels that make gross-up provisions function as a systematic tenant tax.
Before 2020, a building with 85% occupancy using a 95% gross-up target created a 1.12x multiplier, an 11.8% overstatement of variable costs. That was manageable and arguably within the spirit of the provision.
Today, the same provision applied to a 45% occupied building creates a 2.11x multiplier. A tenant paying $80,000 annually in grossed-up CAM charges might owe only $38,000 based on actual costs. The $42,000 gap is pure overcharge enabled by a provision written for a different market reality.
The systematic nature of the problem is what makes it so costly for tenants. Every NNN tenant in a low-occupancy office building with a gross-up clause is experiencing this overcharge simultaneously. It is not an error: it is the provision functioning exactly as written, applied to conditions it was never designed for.
| Market | Office Vacancy Rate (Q4 2024) | Gross-Up Multiplier at 95% Target |
|---|---|---|
| San Francisco | 36.2% | 1.49x |
| Chicago | 26.8% | 1.30x |
| New York City | 22.4% | 1.22x |
| Atlanta | 23.1% | 1.24x |
| Houston | 25.9% | 1.28x |
| Dallas | 24.6% | 1.26x |
| National Average | 19.4% | 1.18x |
Sources: CBRE U.S. Office Figures Q4 2024; JLL Office Market Statistics Q4 2024.
Even at the national average vacancy rate of 19.4%, a gross-up provision targeting 95% creates a 1.18x multiplier: tenants pay 18% more than actual variable costs justify.
Here is a worked example showing dollar impact at three occupancy scenarios.
Building parameters:
Your pro-rata share = 5,000 / 200,000 = 2.5% Your annual CAM cost = $600,000 × 2.5% = $15,000
| Building Occupancy | Gross-Up Multiplier | Inflated Variable Pool | Your 2.5% Share | Annual Overcharge vs. Actual |
|---|---|---|---|---|
| 65% occupied | 1.46x | $876,923 | $21,923 | $6,923 |
| 50% occupied | 1.90x | $1,140,000 | $28,500 | $13,500 |
| 40% occupied | 2.375x | $1,425,000 | $35,625 | $20,625 |
At 40% occupancy, gross-up more than doubles your actual variable CAM obligation. A tenant on a 5-year lease in a building that drops from 65% to 40% occupancy over that term could pay over $80,000 in cumulative gross-up-driven overcharges.
These numbers assume gross-up is applied correctly to variable expenses only. If the landlord is grossing up fixed costs too, the overcharge is higher.
Certain CAM line items are fixed regardless of occupancy level. Applying gross-up to these expenses is improper and the resulting charge is recoverable. For a complete treatment, see our guide to expenses never subject to gross-up.
Fixed expenses that should not be grossed up:
When you request a CAM reconciliation audit trail, ask the landlord to identify which line items were subject to gross-up and the occupancy figure used. If you see fixed-cost categories in the grossed-up pool, you have a specific and documentable violation.
CAMAudit's Rule 5 (Gross-Up Violation) runs a two-part test on every reconciliation:
Part 1: Occupancy verification. The rule extracts the actual occupancy percentage from the CAM statement or lease documents and compares it to the gross-up assumption used. If the landlord claimed a 95% occupancy assumption for gross-up purposes but the building operated at 48%, the rule flags the discrepancy.
Part 2: Fixed-versus-variable classification. For every line item in the CAM pool, the rule classifies the expense as variable (gross-up eligible) or fixed (gross-up ineligible) using the lease's expense categories and our internal classification taxonomy. Any line item classified as fixed but included in the gross-up pool is flagged as a violation.
The output is a dollar-level finding: the exact amount by which your CAM charges were inflated due to improper gross-up, with the calculation shown step by step.
“The post-pandemic office vacancy crisis turned gross-up from a minor calibration provision into a structural overcharge engine. Buildings at 40% occupancy are billing tenants as if they were at 95%. I built the gross-up detection rule to catch both the occupancy-assumption abuse and the fixed-cost inclusion problem, because they rarely happen in isolation.”
Step 1: Get the gross-up calculation from the landlord. Request the CAM reconciliation workpapers showing the gross-up computation: what occupancy percentage was used, which expense categories were subject to gross-up, and the resulting inflated pool total.
Step 2: Verify the actual occupancy percentage. Building occupancy data is typically available from the landlord's annual report or leasing supplement. You can also cross-reference publicly available data from commercial data providers for major markets.
Step 3: Identify fixed-cost inclusions. Go through the gross-up pool line by line and flag any items that are structurally fixed: taxes, insurance, roof, management fees by percentage. Each fixed item in the gross-up pool is a separate sub-finding.
Step 4: Calculate the overcharge. For each year in your lookback period, recalculate your share of actual variable expenses without gross-up applied to fixed costs. The difference between what you were billed and what you should have been billed is the recoverable overcharge.
Step 5: Send a dispute letter draft. The letter should cite the specific lease section that authorizes gross-up, show the actual vs. claimed occupancy, list the improperly included fixed expenses, and state the total annual and cumulative overcharge.
If you are approaching a renewal or negotiating a new lease in a high-vacancy market, these provisions directly limit gross-up abuse:
Cap the gross-up occupancy assumption. Instead of allowing gross-up to 95%, negotiate a cap tied to actual market conditions, for example "the greater of actual occupancy or 85%." In a market with 25% vacancy, this prevents the multiplier from exceeding 1.18x.
Define the eligible expense categories explicitly. Require the lease to enumerate which line items are subject to gross-up. Any expense not on the enumerated list cannot be grossed up.
Require annual occupancy disclosure. Require the landlord to disclose the actual building occupancy percentage used in each year's gross-up calculation in the reconciliation statement. This creates an audit trail and deters manipulation.
Exclude fixed costs by definition. Add explicit lease language: "The gross-up provision applies only to variable operating expenses. Property taxes, insurance premiums, management fees, and capital improvement costs are not subject to gross-up adjustment."
Limit gross-up to Variable Operating Expenses only. Many leases use the undefined phrase "CAM expenses" in the gross-up provision. Push to replace it with "Variable Operating Expenses, defined as expenses that directly scale with building occupancy, including janitorial, trash removal, common area utilities, and HVAC maintenance, but excluding all fixed costs."