What Is a Gross-Up Clause in a Commercial Lease?

A gross-up clause adjusts certain variable operating expenses in a commercial lease to what they would have been if the building had been fully occupied. The adjustment prevents vacancy-driven distortions from inflating tenant charges in base-year leases or penalizing occupied tenants for costs that vacant space should bear.

The core problem the clause solves: some building expenses — janitorial, utilities, certain HVAC costs — scale with occupancy. When a building is 40% occupied, these costs are low. When it fills to 95%, they rise. In a base-year lease that locks in a low-occupancy year as the expense baseline, every subsequent year looks like an "increase" even if nothing changed except that more space became occupied. A gross-up clause corrects for this by normalizing the base year figure to a stabilized occupancy level, usually 95%.

Gross-up provisions are most common in office leases with base-year structures, according to BOMA's operating expense reconciliation guidance, but the same principle applies in any lease where variable expenses form part of the CAM or operating expense pool.

The Mechanics: How a Gross-Up Calculation Works

The gross-up applies only to variable expenses: costs that rise or fall with occupancy. Fixed expenses like property taxes and insurance do not change based on how many tenants are in the building, so grossing them up would produce a false inflation.

Step 1: Identify variable expenses. Common examples include:

• Janitorial and cleaning services
• Electricity and gas for tenant spaces (not base building mechanical)
• Water and sewer (where tenant usage drives the total)
• Trash removal
• Management fees where the fee is tied to occupancy or tenant services

Step 2: Determine actual occupancy in the base year. If the building was 60% occupied in the base year, the variable expenses reflect 60% occupancy.

Step 3: Gross up to the target occupancy. Divide actual variable expenses by the actual occupancy rate and multiply by the target occupancy rate.

Grossed-up expense = Actual expense × (Target occupancy % ÷ Actual occupancy %)

Example: Base year variable operating expenses are $200,000 at 60% occupancy. Target occupancy is 95%.

Grossed-up expense = $200,000 × (95% ÷ 60%) = $316,667

The $316,667 becomes the base year variable expense figure for escalation purposes. Subsequent years are compared against this figure, not $200,000.

Why the Gross-Up Matters for Tenants in Base-Year Leases

The structural risk in a base-year lease is that the base year becomes a permanent comparison floor. Every subsequent year's increase is measured against that fixed floor.

If the base year had artificially low variable expenses because the building was under-occupied, the effect compounds:

• Year 2: The building fills to 80% occupancy. Variable expenses rise to $266,667. Against a non-grossed base of $200,000, your escalation charge is $66,667 — even though the cost increase was entirely due to new occupants, not inflation.
• Year 3: Building reaches 90%. Variable expenses are $300,000. Escalation charge against the non-grossed base: $100,000.

With a properly grossed base year at 95% ($316,667), year 3's expense of $300,000 shows no escalation above base at all. The tenant owes nothing on operating cost increases because the building still hasn't reached the normalized base level.

Practitioners consistently describe this as a multi-year structural overcharge. The error is embedded in the base year and recurs every year for the lease term, regardless of what the landlord actually spends.

Which Expenses Qualify for Gross-Up

The variable/fixed distinction is the central gross-up drafting issue. Most lease disputes arise from ambiguity about which categories are "variable."

Clearly variable (eligible for gross-up):

• Janitorial and cleaning
• Tenant-space utilities (where metered per-tenant or clearly usage-driven)
• Trash removal and recycling
• Pest control
• Certain management fees tied to occupied area

Clearly fixed (not eligible for gross-up):

• Real property taxes and special assessments
• Insurance premiums
• Common area lighting (not tenant-space utilities)
• Roof insurance and structural insurance
• Most capital expenditure amortization

Gray areas requiring explicit lease language:

• HVAC costs (base building mechanical vs. tenant-space conditioning)
• Security (guard services may scale with occupancy; physical access systems may not)
• Management fees (fixed percentage vs. occupancy-based)

BOMA's reconciliation guidance notes that leases should explicitly identify which categories are variable versus fixed to prevent gross-up scope disputes. Without that specification, a landlord could gross up fixed expenses, inflating the base year above what stabilized occupancy would produce.

In Munck Wilson Mandala LLP v. Jordan (N.D. Tex. Aug. 22, 2023), the plaintiff alleged the defendants used gross-up mechanics to gross up categories not impacted by occupancy and manipulated the square footage inputs used to compute occupancy percentages. While the court dismissed the RICO theory and characterized the dispute as a contract matter, the case illustrates that gross-up misapplication does produce litigation.

The Occupancy Target: Why 95% Is the Standard

Practitioner guidance repeatedly frames "full occupancy" stabilization at 95%–100%, with 95% most common as a practical threshold. The reasoning:

• Very few multi-tenant buildings ever reach 100% occupancy for an extended period
• 95% represents a normalized, stabilized operating state
• Using 100% would overstate base-year expenses and penalize tenants with an artificially high base

From a negotiating standpoint, the occupancy target matters because a lower target (say, 75%) understates the grossed-up base year figure and produces larger escalation charges in subsequent high-occupancy years. A higher target (95%–100%) sets a higher base, reducing escalation exposure.

What to request: A gross-up target of 95% of rentable area occupied, applied only to variable expenses as defined in a lease exhibit, using actual expense data adjusted to the target occupancy rate.

Common Gross-Up Errors in Annual Reconciliations

When reviewing a landlord's annual CAM reconciliation, verify:

1. Was the correct occupancy percentage used? Landlords sometimes use a blended or weighted average occupancy that underreports actual occupancy in the base year, producing a lower gross-up figure and a higher escalation base.

2. Were fixed expenses grossed up? If the landlord's gross-up calculation includes property taxes or insurance, those figures are inflated beyond what occupancy-based normalization justifies.

3. Was the same occupancy calculation method used in the base year and subsequent years? If the landlord used leasable area for the base year occupancy calculation but occupied area for subsequent years, the comparison is distorted.

4. Is the gross-up applied at all? In low-occupancy base years, landlords may simply use actual expenses without grossing up, knowing the low base will generate escalation charges as occupancy rises.

Gross-Up vs. Pro-Rata Share: What's the Difference

These two provisions address different problems:

• Pro-rata share determines what fraction of total building expenses you pay (your square footage divided by the total leasable area).
• Gross-up determines what the base year expenses should have been at normalized occupancy, for purposes of calculating year-over-year escalation.

A tenant can have a correct pro-rata share calculation and still be overcharged because the base year expenses were not grossed up. The two provisions interact in base-year leases: the pro-rata share applies to the escalation amount, and the escalation amount depends on whether the base was grossed up correctly.

See How to Negotiate a Base Year Gross-Up Provision for the specific language to request during lease negotiations.

Frequently Asked Questions

Does a gross-up clause benefit landlords or tenants?

Both, depending on context. In base-year escalation leases, a properly applied gross-up that raises the base year figure benefits tenants by reducing the "escalation" in years when occupancy rises. However, landlords sometimes present gross-up provisions as protecting their ability to recover full operating costs — which is also true, in the sense that variable costs should reflect stabilized operations. The key is whether the gross-up applies only to variable expenses and uses a defensible occupancy target.

Is a gross-up clause required in every commercial lease?

No. Gross-up clauses are most relevant in base-year escalation leases, which are most common in office properties. In NNN leases where tenants pay actual pro-rata expenses without a base year comparison, the gross-up mechanism is less important because there is no fixed base to distort. Some NNN leases include gross-up provisions anyway to address vacancy-driven spikes, but the structural exposure is lower.

Can a landlord gross up expenses to 100% occupancy?

Some leases specify 100% as the gross-up target. This is more landlord-favorable because it produces a higher base year figure, which reduces escalation charges in subsequent years. But 100% also means the base year figure exceeds what the landlord actually paid, which can feel like double-counting. The 95% standard represents the market norm from published practitioner sources.

What happens if the gross-up clause is silent on which expenses are variable?

The ambiguity creates a dispute risk. Courts will typically look to the plain meaning of "variable" under the lease and the parties' course of dealing. If the lease lacks an exhibit defining variable versus fixed expenses, the tenant's audit leverage depends on demonstrating that a specific category is logically fixed (does not vary with occupancy) using building records. Inserting a variable expense exhibit at lease execution is far less expensive than litigating the question after a dispute arises.

Does a gross-up clause apply to every year of the lease, or only the base year?

The classic gross-up applies only to the base year in escalation leases. Some leases extend the gross-up to all subsequent years as well, requiring the landlord to adjust each year's expenses to a 95% occupancy standard before comparing to base. That approach benefits tenants in buildings with fluctuating occupancy but creates complexity in reconciliation calculations.

Related reading:

• The Commercial Tenant's Guide to CAM Lease Language — complete provision-by-provision guide
• How to Negotiate a Base Year Gross-Up Provision
• Pro-Rata Share: GLA vs. GLOA — Which Denominator Protects Tenants?
• CAM Exclusions Every Commercial Lease Should Have