In a base year lease, everything hinges on the base year. Your rent increases are measured against the operating expenses incurred in that single year, so the composition of the base year determines what you pay for the entire term. Base year exclusions are the costs you negotiate out of that baseline, and they are among the most valuable clauses a tenant can secure.
The logic is counterintuitive at first. You want the base year number to be as high as legitimately possible, because a higher baseline means smaller increases in later years. Exclusions remove costs that artificially depress the base year or that should never have been in your expense pool at all. Getting them right protects your budget for years.
Why the Base Year Matters So Much
Consider a tenant whose base year operating expenses are 10 dollars per square foot. If expenses rise to 12 dollars in year two, the tenant pays its share of the 2 dollar increase. But if 1.50 dollars of the base year figure consisted of one-time costs that will never repeat, the true recurring baseline was only 8.50 dollars, and the real increase is 3.50 dollars. The tenant overpays because the base year was polluted.
This works in the other direction too. If the base year was artificially low because the building was half empty or because the landlord deferred maintenance, every subsequent year looks like a large increase. Base year exclusions clean up both problems by removing costs that distort the baseline in either direction.
The base year is also the year you know least about when you sign. You negotiate the lease before the base year ends, sometimes before it begins. Exclusions are your way of controlling a number you cannot yet see, by defining in advance what it may and may not contain.
One-Time Costs to Exclude
Non-recurring items are the most important category of base year adjustments, but the tenant’s concern runs in a specific direction. One-time costs that inflate the base year actually help you, since a higher baseline means smaller future increases. The real danger is one-time savings and credits that depress the base year.
A large insurance refund, a one-time tax abatement, or a utility rebate received in the base year makes expenses look lower than their true recurring level. When those benefits disappear the next year, expenses jump and you pay the increase. Exclude one-time credits and refunds from the base year so the baseline reflects sustainable costs.
Similarly, exclude the amortization of capital expenses that began before the base year but will end during your term. When that amortization burns off, expenses drop, which helps you. But if new capital projects replace it, the comparison gets muddy. Clean baselines make every future reconciliation easier to verify.
Costs That Should Never Be in the Base Year
Certain costs should be excluded from operating expenses entirely, in the base year and every year after. These include the landlord’s debt service, depreciation, leasing commissions, tenant improvement allowances for other tenants, costs of initial construction, and expenses for space the landlord holds vacant for its own account.
Related-party charges deserve special scrutiny in the base year. If the landlord’s affiliated management company charged above-market fees during the base year, that inflates the baseline, which helps you. But if the affiliate charged below-market fees as a lease-up incentive and plans to raise them later, the base year is artificially depressed and you will pay for the normalization. Require that related-party charges in the base year reflect market rates.
Capital expenses that benefit only the landlord or specific other tenants should be excluded. A lobby renovation designed to attract higher rents, or a building system upgrade required by another tenant’s use, is the landlord’s investment. Letting these costs sit in the base year distorts your baseline and your future increases alike. Our guide to operating expense exclusions tenants should know covers the full list of costs to strike.
The Occupancy Problem and Gross-Up
The single biggest base year distortion is low occupancy. A building that was 60 percent occupied during the base year had lower variable costs for cleaning, utilities, and services than it will at full occupancy. Without adjustment, the base year understates true operating costs, and you pay for the building’s lease-up as if it were cost inflation.
The fix is a gross-up clause, which adjusts base year variable expenses to reflect a deemed occupancy level, typically 95 percent. This is arguably the most important base year protection a tenant can negotiate, and it belongs in every base year lease. If your lease lacks one, add it before signing.
Gross-up interacts with exclusions, so coordinate them. The gross-up should apply to the base year expenses after exclusions are removed, so you are grossing up a clean number. And the exclusion list should be drafted to work at any occupancy level, not just the actual base year occupancy. Define both provisions to reference the same clean expense pool.
Negotiating the Exclusion List
Start with a comprehensive exclusion exhibit rather than relying on general language. List every category of cost to be removed from the base year: debt service, depreciation, leasing commissions, capital expenses beyond amortization, related-party markups, costs of vacant space held by the landlord, fines and penalties caused by the landlord, and any expense that primarily benefits other tenants or the landlord itself.
Push for a most-favored treatment on new exclusions. Operating expense practices evolve, and a cost nobody thought to exclude when you signed may become significant later. A clause stating that any expense excluded from any other tenant’s base year is excluded from yours keeps your protections current without renegotiation.
Address the base year audit explicitly. Your lease should give you the right to audit the base year expenses within a reasonable window after the base year ends, typically 60 to 90 days after you receive the base year statement. Without this right, the exclusion list is unenforceable because you cannot verify compliance.
Before finalizing any of these terms, review the complete operating expense section with the methodical approach described in our guide to reading your lease before signing. Base year provisions hide in dense paragraphs where small wording choices have large financial consequences.
How Exclusions Affect Future Years
Base year exclusions do more than set the baseline. The categories you exclude from the base year should generally be excluded from every subsequent year’s expenses too. Otherwise you create an asymmetry: a cost excluded from the base year but included later shows up as pure increase, which is the worst possible treatment.
Make the exclusion list apply to the defined term “Operating Expenses” throughout the lease, not just to the base year calculation. This single drafting choice ensures symmetry between the baseline and every comparison year. Your auditor will thank you, because symmetric definitions make reconciliations straightforward to verify.
Frequently Asked Questions
Should the base year be high or low for the tenant?
Higher is better for the tenant, because increases are measured against the baseline. But the base year should be honestly high, reflecting true recurring costs at realistic occupancy, not inflated with improper items. Exclusions remove distortions in both directions to produce a clean, defensible baseline.
What if the landlord will not share base year expense details?
Insist on audit rights and a detailed base year statement as a lease condition. A landlord that refuses transparency about the baseline is asking you to write a blank check on future increases. If they truly will not share, negotiate a fixed expense stop instead of a base year structure.
Do exclusions apply to every year or just the base year?
They should apply to every year. Draft the exclusion list as part of the operating expense definition so it governs the base year and all comparison years symmetrically. Asymmetric exclusions create phantom increases.
Can I negotiate base year terms after signing?
It is very difficult. Base year provisions are structural lease terms, and landlords have little incentive to reopen them. Address exclusions, gross-up, audit rights, and floors during initial negotiation, when your leverage is greatest.
Base year exclusions are unglamorous, technical, and enormously valuable. They determine the baseline against which every future increase is measured, which means they affect every operating expense payment you will ever make under the lease. Negotiate a comprehensive exclusion list, pair it with gross-up protection and audit rights, and apply the definitions symmetrically to every year. Tenants who do this work before signing enjoy clean reconciliations and predictable costs. Tenants who skip it spend the term arguing about a baseline they never controlled.
