A triple net lease shifts most of the costs of owning a building from the landlord to the tenant. The tenant pays base rent plus their share of property taxes, building insurance, and maintenance, the three “nets” that give the lease its name. In exchange, the base rent is lower than it would be under a gross lease.
Triple net leases (NNN leases) are common in retail, single-tenant freestanding properties, and a growing share of industrial and office space. For tenants, they trade predictability for lower base rent and direct control over operating costs. Whether that trade is worth it depends on the building, the tenant’s operating expense management, and how the lease is negotiated.
Key Takeaways
- A triple net lease passes property taxes, building insurance, and maintenance costs from landlord to tenant on top of base rent.
- Tenant cost share in multi-tenant buildings is calculated pro rata by square footage. A tenant occupying 20% of a building pays 20% of the pass-through expenses.
- Base rent under NNN is lower than under gross or modified gross leases. The trade-off is variable annual costs and exposure to expense increases.
- Caps on annual increases, expense audits, and clear definitions of what counts as maintenance versus capital improvement are the most important negotiation points for tenants.
The three commercial lease types
Most commercial leases fall into one of three categories, distinguished by which costs the landlord covers and which the tenant absorbs.
| Lease type | Tenant pays | Landlord pays | Common in |
|---|---|---|---|
| Gross (Full Service) | Flat rent only | Property taxes, insurance, maintenance, utilities, common area costs | Office buildings, coworking, traditional Class A office |
| Modified Gross | Base rent plus utilities and interior upkeep | Property taxes, insurance, structural maintenance, common area costs | Multi-tenant office, some industrial |
| Triple Net (NNN) | Base rent plus property taxes, insurance, and maintenance | Structural elements (sometimes), property management | Single-tenant retail, freestanding properties, drive-thru QSR, drug stores, dollar stores, industrial |
The differences come down to how operating expenses are allocated. A gross lease bundles everything into one number; a triple net unbundles it. Reading the lease structure carefully is the only way to know what you’re actually committing to.
What the three “nets” cover
The N stands for “net of.” A triple net lease is net of three categories of expenses, all paid by the tenant on top of base rent:
Property taxes. The tenant covers their share of the building’s annual real estate tax bill, which is usually billed monthly or quarterly with reconciliation at year end. Property taxes can rise meaningfully year over year, especially after a building is reassessed. The commercial property tax structure varies by jurisdiction, so what looks predictable in one market may be volatile in another.
Building insurance. The tenant pays for the property insurance the landlord carries on the building itself. This is separate from the tenant’s own liability or contents insurance, which the tenant carries regardless of lease type.
Common area maintenance (CAM). CAM covers the shared building expenses: parking lot upkeep, landscaping, exterior lighting, HVAC servicing for shared systems, snow removal, common area cleaning, and similar items. CAM is usually the most contested category in NNN leases because the definition of what qualifies can vary widely between landlords.
How tenant cost share is calculated
In a single-tenant building, the tenant pays 100% of the three nets. In a multi-tenant building, costs are divided pro rata by square footage. A tenant occupying 5,000 square feet in a 25,000-square-foot building pays 20% of the building’s annual property taxes, insurance premium, and CAM expenses.
Pro rata math is straightforward but the inputs aren’t always. Buildings can include a load factor that adds common area square footage to a tenant’s billable space, which changes the denominator. Read the lease definition of “rentable square feet” carefully. The commercial rent calculation for NNN leases needs to account for both base rent and the variable pass-through component.
A worked example
Consider a 5,000-square-foot retail space leased at $24 per square foot per year on a triple net basis, in a building where pass-through expenses run $6 per square foot.
| Base rent (5,000 sq ft × $24/sq ft) | $120,000/year |
| NNN expenses (5,000 sq ft × $6/sq ft) | $30,000/year |
| Total annual cost | $150,000 |
| Total monthly cost | $12,500 |
The tenant’s effective all-in rate is $30 per square foot, but the lease will quote it as $24 NNN. Comparing this to a gross lease quoted at $30 per square foot for similar space, the all-in cost is identical at signing. The difference shows up over time. Under the gross lease, the tenant’s payment stays flat (or rises only by a contractual escalator). Under the NNN lease, the $6 pass-through can increase if property taxes go up, insurance premiums rise, or maintenance costs escalate.
Variations within net leases
Not all net leases are triple net. The category includes four variations, distinguished by which expenses pass through to the tenant.
| Lease type | Tenant pays | Where it’s used |
|---|---|---|
| Single net (N) | Property taxes only | Rare in modern commercial leasing |
| Double net (NN) | Property taxes + building insurance | Office and mixed-use buildings |
| Triple net (NNN) | Property taxes + insurance + maintenance | Most common net lease structure |
| Absolute net (NNN+) | All expenses, including roof, structure, and casualty rebuilding | Long-term (15-25 year) leases with creditworthy single tenants; common in STNL investing |
Absolute net leases are sometimes called bondable leases because the tenant’s obligations are essentially absolute. The lease is treated more like a credit instrument than a real estate agreement.
What tenants should negotiate
The base rent is rarely the most important number in an NNN lease. The pass-through structure is where money is won or lost over the lease term.
The most useful protections to negotiate:
CAM caps. A cap on the annual increase in CAM expenses (commonly 3-5% per year, or tied to CPI) limits the tenant’s exposure to runaway operating costs. Without a cap, a tenant who signed a 10-year lease can find their pass-through bill 50% higher in year ten than year one.
Exclusions from CAM. Capital improvements, property management fees beyond a market rate, the landlord’s overhead, and certain types of major repairs should be excluded from what the tenant pays through CAM. Lease language matters here. “Maintenance” and “repairs and replacements” can mean very different things depending on how the lease defines them.
Audit rights. The right to audit the landlord’s CAM reconciliation each year, with the landlord paying audit costs if material errors are found. CAM reconciliations frequently contain errors; without audit rights, the tenant has no leverage to challenge them.
Base year or expense stop. A mechanism that establishes a baseline for pass-throughs in year one and limits the tenant’s exposure to increases over that baseline. More common in modified gross leases but can be negotiated into NNN leases for stronger tenants.
NNN as a landlord and investor asset class
Single-tenant net lease properties (often called STNL) are a major investor asset class. The appeal for investors is predictable income with minimal management burden: the tenant handles operating expenses, so the landlord’s net income is largely insulated from cost increases. Long-term NNN leases with creditworthy tenants (national pharmacy chains, dollar stores, drive-thru restaurants, fitness operators, cell towers) trade as bond-like investments.
For tenants, this means the landlord on the other side of a NNN lease is often an investor focused on yield and credit quality, not an operator focused on the building itself. That can affect how lease negotiations go and how landlord-side responsibilities are handled when something does require landlord attention.
Is a triple net lease right for your business?
For tenants who can manage operating expenses well, who plan to occupy the same space for many years, and who want a lower base rent in exchange for variable pass-throughs, NNN can work. For tenants who need predictable monthly costs, who don’t have the bandwidth to track and challenge CAM reconciliations, or who plan to be in a space for only a few years, a gross or modified gross lease usually fits better.
The decision is rarely about the lease type in the abstract. It’s about how the specific lease is structured: what’s capped, what’s excluded, what’s auditable, and what the actual base rent and pass-through numbers look like for the building you’re considering.
Frequently Asked Questions
- What does NNN stand for in a lease? NNN stands for “net of” three categories of expenses: property taxes, building insurance, and maintenance. In a triple net lease, the tenant pays base rent plus their share of these three expenses, while the landlord covers structural elements and property management.
- How is the tenant’s share of NNN expenses calculated? In a multi-tenant building, the tenant’s share is calculated pro rata by square footage. A tenant occupying 5,000 square feet in a 25,000-square-foot building pays 20% of the building’s property taxes, insurance, and maintenance expenses. In a single-tenant building, the tenant pays 100%.
- Is a triple net lease better for tenants or landlords? NNN leases benefit landlords by transferring operating expense risk to tenants and producing predictable net income. For tenants, NNN can work well when the base rent reduction offsets the variable pass-throughs and when the lease includes caps and audit rights. The structure is neutral; what matters is how it’s negotiated.
- What is CAM and why does it matter? CAM stands for common area maintenance, the shared building expenses including parking lot upkeep, landscaping, exterior lighting, HVAC servicing, snow removal, and common area cleaning. CAM is usually the most contested category in NNN leases because what qualifies as CAM varies widely. Tenants should negotiate clear definitions, exclusions, and caps on annual increases.
- What is the difference between triple net and absolute net? A standard triple net lease leaves the landlord responsible for some structural elements and major capital items. An absolute net or bondable lease shifts essentially all responsibility to the tenant, including roof replacement, structural repairs, and sometimes even rebuilding after a casualty. Absolute net leases are most common with creditworthy tenants on long-term (15-25 year) commitments.
- What should tenants negotiate in a triple net lease? The most important protections are caps on annual CAM increases (typically 3-5% or CPI-tied), clear exclusions from CAM (capital improvements, landlord overhead), audit rights for the annual reconciliation, and base year or expense stop mechanisms where applicable. Base rent matters less than how pass-throughs are structured over the lease term.
Matthew Preston
Content Writer, CRE News & Market Analysis
Matthew has covered commercial real estate for CommercialCafe since 2022. He focuses on the office and industrial sectors, reporting on leasing, development, and investment across national markets and individual submarkets. His work draws on data and original research. He also writes about demographic shifts and urban innovation in U.S. cities. The New York Times, The Real Deal, Bisnow, The Business Journals, and Yahoo Finance have cited his reporting.
