Commercial Lease Types Explained: Gross, Modified Gross & NNN
Commercial lease types such as gross, modified gross and NNN determine how rent, taxes, insurance, operating expenses, utilities and other occupancy costs are divided between landlords and tenants.
Commercial Lease Types at a Glance
The three commercial lease structures tenants most commonly encounter are gross, modified gross and NNN. The biggest difference is generally how operating expenses and property responsibilities are divided.
More property operating expenses are generally included in the quoted rental rate, although exclusions and expense increases may still apply.
The landlord and tenant divide operating expenses according to the negotiated lease rather than following one universal structure.
The tenant generally pays base rent plus its allocated share of property taxes, insurance and operating or common-area expenses.
The Lease Label Is Only the Starting Point
Commercial lease types are often described as gross, full-service gross, modified gross, or NNN / triple net. Those labels help explain the general structure, but the written lease controls the actual economics.
Two leases using the same label can allocate expenses differently. Review what is included in quoted rent, what is billed separately, how expenses can change, and which maintenance or repair responsibilities remain with the tenant.
Three Common Commercial Lease Types
| Lease Type | General Structure | Tenant Should Review |
|---|---|---|
| Gross / Full-Service Gross | More building operating expenses are typically bundled into stated rent. | Base year, expense stops, utilities, after-hours services, parking and exclusions. |
| Modified Gross | Landlord and tenant divide operating expenses according to the lease. | Which taxes, insurance, utilities, maintenance and CAM charges are included or passed through. |
| NNN / Triple Net | Base rent plus the tenant’s share of property taxes, insurance and operating/common-area expenses. | NNN estimate, history, pro-rata share, reconciliation, fees, utilities and maintenance. |
What Is a Gross or Full-Service Gross Lease?
In a gross-style lease, the landlord generally includes more property operating expenses in quoted rent. That can simplify budgeting, but it does not mean every cost is fixed or included forever.
- Base year: the landlord may include expenses up to a designated year’s level, with the tenant paying later increases.
- Expense stop: the landlord may cover expenses up to a stated amount, with the tenant responsible above that threshold.
- Separately billed items: electricity, parking, after-hours HVAC, janitorial or tenant-specific services may still be extra.
Office users can pair this with our guide on how to evaluate office space before signing a lease .
What Is a Modified Gross Lease?
A modified gross lease sits between a more inclusive gross structure and a more pass-through-heavy NNN structure. The landlord and tenant divide expenses according to the negotiated lease, so the label alone is not enough.
What Is a NNN or Triple-Net Lease?
In a typical NNN lease, the tenant pays base rent plus its share of property taxes, building insurance, and operating or common-area expenses. See what NNN means and our guide to CAM charges for deeper explanations.
Other Commercial Lease Structures You May See
Gross, modified gross and NNN are common commercial lease structures, but tenants may also encounter other terms depending on the property, landlord and transaction.
- Single-net lease (N): the tenant generally pays base rent plus its share of one major operating expense category, commonly property taxes.
- Double-net lease (NN): the tenant generally pays base rent plus its share of two major expense categories, commonly property taxes and insurance.
- Absolute-net lease: a lease may assign a broader range of property costs and responsibilities to the tenant than a typical NNN structure. The actual lease language should be reviewed carefully.
- Percentage lease: a retail lease may include base rent plus a percentage of sales above an agreed threshold or breakpoint.
Gross vs. Modified Gross vs. NNN: A Simple Example
Suppose a business is comparing 5,000 square feet in three different properties. These simplified numbers show why the lease label and quoted rent should be reviewed together.
| Lease structure | Base rent | Added expenses | Combined |
|---|---|---|---|
| Full-service gross | $22.00 | Included expenses: $0 additional | $22.00 |
| Modified gross | $18.00 | Insurance $0.75 + taxes $1.25 + CAM $2.00 = $4.00 | $22.00 |
| NNN | $15.00 | Estimated NNN expenses: $7.00 | $22.00 |
Illustrative 5,000 SF Comparison
Each begins near $22.00/SF/YR. At 5,000 SF, that is about $110,000 per year or $9,167 per month before other applicable costs.
Which Costs May Still Sit Outside the Quoted Rent?
- Tenant-specific utilities or data service
- Parking charges
- After-hours HVAC or building services
- Janitorial inside the suite
- Repairs or maintenance assigned to the tenant
- Signage, security, waste removal or specialty services
- Construction or buildout costs not covered by the landlord
If construction is required, review our tenant improvement allowance guide .
How Square Footage Affects Lease Comparisons
Tenants also need to understand the square footage used to calculate rent. In multi-tenant buildings, billed area may be based on rentable square footage, which can be larger than usable area. See rentable vs. usable square footage .
Questions to Ask Before Comparing Lease Proposals
- What is included in quoted rent?
- Which expenses are estimated pass-throughs?
- Are utilities separately metered or allocated?
- Is there a base year or expense stop?
- How is the tenant’s pro-rata share calculated?
- How and when are expenses reconciled?
- Are management or administrative fees included?
- Who handles HVAC, roof, structure, parking lot and maintenance?
- Can capital repairs or replacements be passed through?
- What square footage is used to calculate rent?
Lease economics are only one part of commercial real estate due diligence. Before committing to a property, also review the broader commercial property due diligence checklist for property, site and transaction considerations.
Which Lease Type Is Best?
There is no single structure that is automatically best. The better question is whether the total economics, responsibilities, building, location and flexibility fit the business. Companies deciding whether to lease at all can review Lease vs. Buy Commercial Property in Michigan .
Lease Structure by Property Type
Gross, modified gross and NNN structures can appear across office , medical office , retail , warehouse space for lease , industrial and other commercial properties. Compare the actual lease language and cost breakdown rather than relying on the label.
The lease structure also does not determine whether a particular business use is allowed at a property. Tenants should separately confirm use and approval requirements; our guide to commercial zoning in Michigan explains how zoning, permitted uses and approvals can affect a location.
How a Commercial Real Estate Broker Can Help
A broker can organize proposals so tenants compare base rent, operating expenses, square footage, buildout, location, building features and other considerations consistently. Crabill & Company provides commercial real estate brokerage services throughout Michigan.
Commercial Lease Type FAQs
What are the main commercial lease types?
Common commercial lease types include gross or full-service gross, modified gross and NNN or triple-net leases. Depending on the property, tenants may also encounter single-net, double-net, absolute-net or percentage lease structures.
What is the difference between a gross lease and a NNN lease?
A gross-style lease generally bundles more property operating expenses into stated rent, while a typical NNN lease separates base rent from taxes, insurance and operating expenses.
What does modified gross mean?
The landlord and tenant divide operating expenses according to the lease. There is no universal split.
Is full-service gross the same as gross?
The terms often describe leases where more expenses are included, but base-year provisions, expense stops, utilities and exclusions may still apply.
Does a NNN lease make the tenant responsible for every repair?
No. Maintenance and repair responsibilities vary by lease and property.
How should tenants compare two commercial leases?
Compare total occupancy cost, square footage, expense responsibilities, buildout costs, location, features and flexibility—not only base rent.
Comparing Commercial Space in Michigan?
Use lease structure as one part of the decision, then compare total occupancy cost, building, location, square footage and business fit.
This article is for general educational purposes and is not legal, tax, accounting or financial advice. Lease terminology and responsibilities vary by transaction.