Verify CAM gross-up math and catch vacancy exploitation. Use the exact formula to test whether your landlord inflated variable expenses during low occupancy.
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Find My OverchargesSee a sample report firstThe gross-up calculation formula is: Threshold Occupancy / Actual Occupancy x Variable Expenses. It applies only to costs that scale with occupancy: janitorial, utilities, HVAC. Property taxes, insurance, and fixed-rate contracts cannot be grossed up because they do not change with building occupancy. When a landlord applies gross-up to fixed expenses on a building at 72% occupancy with a 95% threshold, the overcharge on a $320,000 fixed expense pool exceeds $100,000 building-wide, or $10,000+ for a tenant with a 10% pro-rata share.
Your landlord's building ran at 72% occupancy last year. So they grossed up the operating expenses to normalize them to 95%. That sounds reasonable. It isn't, if they applied the gross-up factor to property taxes and insurance.
40% of commercial CAM reconciliations contain material billing errors, including gross-up violations (Tango Analytics, 2023)
The gross-up provision in a commercial lease allows a landlord to normalize variable operating expenses to a full-occupancy baseline when actual occupancy falls below a threshold. Applied correctly, it protects both parties. Applied incorrectly, it inflates CAM charges beyond what the building's actual full-occupancy costs would justify.
Most gross-up errors fall into one of two categories: applying gross-up to expenses that cannot vary with occupancy (property taxes, insurance, fixed contracts), or using a gross-up factor that does not match the lease's defined methodology. Both produce charges above what the lease actually requires. Understanding the gross-up provision is part of a broader review of CAM lease language, which is frequently drafted in ways that give landlords more flexibility than the underlying math justifies.
Key takeaway: Gross-up applies only to expenses that vary with occupancy. Property taxes, insurance premiums, and fixed-rate contracts do not vary with occupancy and cannot be grossed up.
Gross-up applies to variable expenses only. Property taxes, insurance premiums, and fixed-rate contracts do not vary with occupancy and cannot be grossed up. If your reconciliation shows those line items at amounts higher than the actual bills, gross-up was incorrectly applied.
A gross-up provision is a clause in a commercial lease that authorizes the landlord to normalize variable operating expenses to a defined occupancy level (typically 95%) when the building's actual occupancy falls below that threshold.
The problem gross-up solves:
Suppose a commercial office building has variable operating expenses (janitorial, utilities, HVAC operation) that scale with occupancy. At 95% occupancy, the building spends $500,000 on these services. In a year where occupancy drops to 70%, the building spends only $370,000 on the same services.
In a full-service or modified gross lease where tenants pay expenses above the base year, the lower variable expense year creates a problem: if the low-occupancy year becomes the base, then high-occupancy years show large "increases" that tenants must pay. Gross-up prevents this by normalizing the low-occupancy year's variable expenses to what they would have been at full occupancy.
The standard occupancy threshold:
The BOMA Green Lease Guide (2018) establishes 95% occupancy as the industry standard threshold for gross-up normalization. When building occupancy falls below 95%, variable operating expenses may be grossed up to what they would have been at 95% occupancy. The specific threshold in any lease is a negotiated provision. Some leases use 90%, others use 95%, and some use a different percentage. Your lease controls.
The eligibility rule is direct: only expenses that actually vary with building occupancy qualify. Expenses that do not change based on how many tenants occupy the building cannot be grossed up, because there is no "full occupancy level" that is higher than the actual amount.
Variable expenses scale with occupancy. They are higher when more tenants occupy the building and lower when occupancy drops.
Eligible categories:
Fixed expenses do not vary with building occupancy. They are the same at 100% occupancy as at 10% occupancy.
Ineligible categories:
Why it matters: Applying gross-up to property taxes produces a stated "grossed-up" tax expense higher than the actual tax bill. That inflated amount is passed through to tenants as if it were the normalized full-occupancy cost. But taxes cannot physically be higher at full occupancy. The inflated number is pure overcharge.
For a full treatment of which expenses are permanently excluded from gross-up eligibility, see expenses that should never be grossed up.
A correct gross-up calculation follows this process:
Step 1: Identify the occupancy threshold
Find the gross-up clause in your lease. Identify the occupancy threshold below which gross-up is permitted (commonly 95%).
Step 2: Determine actual occupancy
Determine the building's actual occupancy percentage during the reconciliation year. This should be stated in or attached to the reconciliation. If not, request the landlord's occupancy records.
Step 3: Identify eligible variable expenses
From the total operating expenses, identify the expenses that qualify as variable. This requires either: (a) the lease explicitly lists which expenses are variable, or (b) you classify each expense type based on whether it actually scales with occupancy.
Step 4: Calculate the gross-up factor
The gross-up factor normalizes from actual occupancy to the threshold occupancy:
Gross-Up Factor = Threshold Occupancy / Actual Occupancy
Example: threshold 95%, actual 75%: Factor = 95% / 75% = 1.267
Step 5: Apply gross-up only to variable expenses
Grossed-Up Variable Expenses = Actual Variable Expenses x Gross-Up Factor
Step 6: Recombine with non-variable expenses
Total Grossed-Up Operating Expenses = Grossed-Up Variable Expenses + Actual Non-Variable Expenses
The non-variable expenses are added at their actual amounts, not multiplied by the gross-up factor.
Here is where the arithmetic diverges from what landlords often submit. The worked example below shows the dollar gap between a correct gross-up and an incorrect one on a real-scale expense pool.
Building facts:
Gross-up factor: 95% / 72% = 1.3194
Correct gross-up calculation:
| Category | Actual amount | Gross-up applied? | Grossed-up amount |
|---|---|---|---|
| Janitorial | $80,000 | Yes | $105,556 |
| Utilities | $200,000 | Yes | $263,889 |
| HVAC operation | $120,000 | Yes | $158,333 |
| Security | $80,000 | Yes | $105,556 |
| Property taxes | $180,000 | No | $180,000 |
| Insurance | $140,000 | No | $140,000 |
| Total | $800,000 | $953,333 |
Incorrect gross-up calculation (landlord applies gross-up to all expenses):
| Category | Actual amount | Gross-up applied? | Grossed-up amount |
|---|---|---|---|
| Janitorial | $80,000 | Yes | $105,556 |
| Utilities | $200,000 | Yes | $263,889 |
| HVAC operation | $120,000 | Yes | $158,333 |
| Security | $80,000 | Yes | $105,556 |
| Property taxes | $180,000 | Incorrectly yes | $237,500 |
| Insurance | $140,000 | Incorrectly yes | $184,722 |
| Total | $800,000 | $1,055,556 |
Overcharge from applying gross-up to fixed expenses: $1,055,556 - $953,333 = $102,222 in total building overcharge
At a 10% pro-rata share, the tenant's portion is $10,222 per year. Across a five-year lease, that is $51,110 in overcharges from a single calculation error that takes about ten minutes to check.
Property taxes are the most common ineligible expense that appears in gross-up calculations. The tax bill is fixed: it is what it is regardless of occupancy. Applying a gross-up factor to property taxes produces an inflated number that does not correspond to any real additional expense the building would incur at full occupancy.
This violation is straightforward to detect: find the property tax line item in the reconciliation and check whether the stated amount exceeds the actual tax bill. If the reconciliation shows a tax amount higher than county assessor records for the property, gross-up was likely applied.
Insurance premiums are set by the insurer based on building value, coverage type, and risk profile. They do not scale with tenant occupancy. A building insured for $10 million pays the same premium at 100% occupancy as at 50% occupancy.
Applying gross-up to insurance premiums inflates the stated premium above the actual cost. If the reconciliation shows insurance expenses greater than the actual premiums declared on the policy, request the policy declarations and compare.
Some landlords apply a gross-up factor calculated using the wrong occupancy denominator. The occupancy used should be the building's actual occupancy during the reconciliation year, measured in the same units the lease's gross-up provision specifies.
Using 80% as the actual occupancy when the building was actually at 72% understates the gross-up factor and applies a smaller normalization than the lease requires. This error typically works in the tenant's favor, but verifying the factor is part of a complete audit.
When a full-service lease uses a base year that was at below-threshold occupancy, the base year variable expenses should also be grossed up. Some landlords gross up subsequent years but not the base year. This understates the base (making every subsequent year look like a larger increase) and produces systematic overcharges across the lease term.
This is a base year error with a gross-up component. The combination is significant because it compounds: the understated base produces an overcharge, and the ineligible gross-up on fixed expenses adds an additional overcharge layer. When gross-up is applied during the base year, it interacts directly with the CAM reconciliation settlement that arrives years later. See the base year error guide for the full compounding analysis.
Tin Tin LLC v. Pacific Rim Park, LLC, 170 Cal.App.4th 1220 (2009), addressed a dispute over gross-up calculations in a California commercial lease. The California Court of Appeal examined how variable vs. fixed expenses should be treated under the lease's gross-up provision.
The court held that gross-up clauses apply according to their purpose: normalizing variable expenses genuinely affected by occupancy levels. The court rejected the landlord's argument that the gross-up provision could be applied uniformly to all expenses in the pool, finding that the plain language limited its application to variable costs.
Tin Tin is the leading California appellate decision on gross-up application and is regularly cited in commercial lease disputes involving CAM gross-up methodology.
Step 1: Find the gross-up provision in your lease
Locate the occupancy threshold, the definition of eligible expenses, and the calculation methodology. Some leases are explicit about which categories are variable; others leave it to general principle.
Step 2: Obtain actual occupancy data for the reconciliation year
Request the building's occupancy records. If not attached to the reconciliation, these should be available under your lease's audit rights clause.
Step 3: Identify all grossed-up amounts in the reconciliation
Request the landlord's gross-up worksheet if it was not included with the CAM reconciliation statement. The worksheet should show actual expenses, the gross-up factor, and the grossed-up amounts by category.
Step 4: Verify that no fixed expense was grossed up
For each grossed-up category, determine whether it is variable or fixed. Any fixed expense that appears on the grossed-up list is a violation.
Step 5: Verify the gross-up factor
Calculate the gross-up factor yourself: threshold occupancy divided by actual occupancy. Compare to the factor the landlord used. If the factors differ, determine which uses the correct inputs per the lease.
Step 6: Calculate the overcharge
For each ineligible grossed-up expense: Overcharge = (Grossed-Up Amount - Actual Amount) x Tenant Pro-Rata Share. Sum all category overcharges for the total gross-up violation amount.
For context on how gross-up fits within the broader set of CAM billing errors, see the complete CAM audit guide. Gross-up violations frequently appear alongside management fee overcharges, where the inflated gross-up base drives an inflated fee calculation. They also interact with CAM cap violations, where landlords gross up controllable expenses before applying the cap ceiling. High-vacancy buildings compound these errors further, as detailed in the gross-up vacancy exploitation guide. Tenants dealing with pro-rata share errors may also find that an inflated gross-up pool amplifies those errors.
What is a gross-up provision in a commercial lease?
A gross-up provision allows a landlord to normalize variable operating expenses to a defined occupancy level (typically 95%) when the building's actual occupancy falls below that threshold. The purpose is to prevent tenants from paying artificially inflated expense increases in high-occupancy years following a low-occupancy base year. Gross-up only applies to expenses that actually vary with occupancy.
What is the standard gross-up occupancy threshold?
The BOMA Green Lease Guide (2018) establishes 95% occupancy as the industry standard threshold for gross-up normalization. When building occupancy falls below 95%, variable operating expenses may be grossed up to what they would have been at 95%. The specific threshold in any lease is a negotiated provision and may differ from this standard.
Which expenses can be grossed up in a commercial lease?
Only variable operating expenses that genuinely scale with building occupancy are eligible for gross-up: janitorial services, utilities consumption, HVAC operation, trash removal, and occupancy-dependent security. Fixed expenses cannot be grossed up: property taxes, insurance premiums, and fixed-rate service contracts do not vary with occupancy and have no full-occupancy level that is higher than their actual cost.
Can property taxes be grossed up in a commercial lease?
No. Property taxes are a fixed expense assessed by the taxing authority based on the property's assessed value, not on how many tenants occupy the building. Applying a gross-up factor to property taxes produces an inflated number that exceeds the actual tax bill. If your reconciliation shows property tax amounts higher than the actual tax bill, gross-up was incorrectly applied.
How do I calculate if my landlord applied gross-up incorrectly?
Request the landlord's gross-up worksheet. Identify all expenses where gross-up was applied. For each grossed-up expense, determine whether it is variable (eligible) or fixed (ineligible). For any fixed expense where gross-up was applied, the overcharge is the grossed-up amount minus the actual expense amount, multiplied by your pro-rata share. Verify the gross-up factor by dividing the threshold occupancy by the actual occupancy and comparing to the factor the landlord used.
What is the Tin Tin case and why does it matter for gross-up?
Tin Tin LLC v. Pacific Rim Park, LLC, 170 Cal.App.4th 1220 (2009), is a California Court of Appeal decision establishing that gross-up clauses in commercial leases apply only to variable expenses genuinely affected by occupancy levels. The court rejected the landlord's argument that gross-up could be applied uniformly to all expenses in the operating expense pool. The case is the leading California appellate authority on gross-up methodology.
How do I dispute a gross-up violation in my CAM reconciliation?
Document the violation: identify the specific expense categories where gross-up was incorrectly applied, confirm those expenses are fixed (not variable), and calculate the overcharge as (grossed-up amount - actual amount) x your pro-rata share. Send a written dispute letter draft citing your lease's gross-up provision, showing the correct calculation, and requesting a credit for the overcharge amount. Reference Tin Tin v. Pacific Rim Park if you are in California or a jurisdiction that applies similar principles.
