A modified gross lease is a commercial lease in which the tenant pays base rent plus a negotiated share of operating expenses, while the landlord covers the rest. It sits between a gross lease, where the landlord pays all costs, and a triple net lease, where the tenant pays all costs.
How a Modified Gross Lease Works
A modified gross lease works by dividing property operating expenses between landlord and tenant according to terms both sides negotiate at signing. The tenant pays a fixed base rent, plus specified costs such as in-suite utilities or janitorial service, and the landlord absorbs the remaining expenses. There is no standard split.
The three cost buckets that get allocated are property taxes, building insurance, and maintenance, alongside utilities and common area maintenance. In a common structure, the landlord pays the full operating expense load in the first year, and the tenant begins paying its proportionate share of increases after that. Per Voit Real Estate Services, beginning the second year of the lease, tenants are likely to pay a pro-rata share of the building's operating expenses.
That first year is the base year. Voit Real Estate Services defines the base year as the first calendar year of a tenant's commercial rental period, noting that all future expense passthroughs are calculated against it and that the mechanism is crafted to favor landlords by protecting them from steep annual increases in operating expenses. The table below shows a representative allocation, not a fixed rule.
Expense | Typical landlord obligation | Typical tenant obligation |
|---|---|---|
Base rent | None | Full |
Property taxes | Up to base year amount | Increases over base year |
Building insurance | Up to base year amount | Increases over base year |
Common area maintenance | Up to base year amount | Pro-rata increases |
In-suite utilities | None | Full |
Structure and roof | Full | None |
Why a Modified Gross Lease Matters
A modified gross lease matters because it decides which party carries the risk of rising operating costs, and that allocation flows straight into net operating income. A gross lease leaves the landlord absorbing every cost increase. A modified gross lease lets the landlord recover expense growth above the base year once costs exceed the agreed threshold, defending margin without pushing the full expense burden onto the tenant.
The base year is where the money is won or lost. A base year drawn from a period of abnormally high expenses inflates the baseline, so costs have to climb further before passthroughs begin, which quietly hands value to the tenant. The quotable point for an operator: in a modified gross lease, the landlord pays for cost increases until they cross the base year, so the base year figure is the single term that sets how much the owner absorbs before the tenant starts to pay.
Example
Consider a tenant occupying 10% of a multi-tenant office building on a modified gross lease with a base year set by year-one operating expenses of $500,000. In year two, building operating expenses rise to $560,000, a $60,000 increase over the base year. The tenant pays its pro-rata share of that increase: 10% of $60,000, or $6,000, on top of base rent. The landlord still absorbs the base year amount.
The table below places the same categories across the three main lease types, showing who carries each cost. It uses a representative modified gross split; the actual division is negotiated deal by deal.
Expense | Gross lease | Modified gross lease | Triple net lease |
|---|---|---|---|
Property taxes | Landlord | Increases over base year to tenant | Tenant |
Building insurance | Landlord | Increases over base year to tenant | Tenant |
Common area maintenance | Landlord | Pro-rata increases to tenant | Tenant |
In-suite utilities | Landlord | Tenant | Tenant |
Structure and roof | Landlord | Landlord | Tenant |
Variations and Edge Cases
A modified gross lease is a negotiated middle ground, so its terms vary more than either a gross or a triple net lease. The variants below change how much expense risk actually shifts to the tenant, and an operator underwriting the income stream should confirm each one before relying on projected passthroughs.
Variant | Treatment |
|---|---|
Base year passthrough | Tenant pays its share of expense increases above the first-year baseline |
Expense stop | Landlord's obligation is capped at a fixed dollar figure; tenant absorbs the overage above it |
Industrial gross | Common in warehouse and flex space; tenant often adds its own utilities and interior repairs |
Gross-up clause | Per the Law Offices of Mark Weinstein, expenses are amplified to what a fully occupied building would incur, limiting a tenant's exposure to variable costs as occupancy changes |
Renewal reset | Base year can be renegotiated at renewal, resetting the baseline against which passthroughs are measured |
The frequent mistake is treating "modified gross" as a defined product. It is a label for any split between fully gross and fully net, and the lease language, not the name, controls who pays.
Modified Gross Lease vs Full-Service Gross Lease
A modified gross lease is often confused with a full-service gross lease, and the difference is who pays operating expenses. A full-service gross lease bundles all operating costs, including property taxes, insurance, utilities, and common area maintenance, into a single rent the landlord pays out of. A modified gross lease carves specific costs out of that bundle and assigns them to the tenant.
Voit Real Estate Services frames the modified gross lease as a full-service gross lease with minor exceptions, a blend between a gross lease and a net lease. A tenant with unusual demands, such as heavy electrical power requirements, might take a modified gross lease so the landlord does not absorb costs that a full-service structure would otherwise bury in base rent.
Frequently Asked Questions
What is the difference between a modified gross lease and a triple net lease? In a modified gross lease, the landlord and tenant split operating expenses, and the landlord typically absorbs costs up to the base year. In a triple net lease, the tenant pays all operating expenses, including property taxes, insurance, and maintenance, on top of base rent. The modified gross structure leaves more cost risk with the landlord.
Who pays property taxes in a modified gross lease? It depends on the negotiated terms. In a common structure, the landlord pays property taxes up to the base year amount, and the tenant pays its pro-rata share of any increase above that baseline. The specific allocation is set in the lease, so property tax responsibility can differ from one modified gross lease to the next.
What is a base year in a modified gross lease? The base year is the first calendar year of the lease, and it sets the expense baseline against which future passthroughs are measured. Per Voit Real Estate Services, all future expense payments are calculated using the base year, and the mechanism is designed to protect landlords from steep annual increases in operating expenses.