A NNN lease agreement, or triple net lease, is a commercial real estate lease in which you pay a base rent plus your pro-rata share of three property expenses: real estate taxes, building insurance, and common area maintenance. That structure moves most of the building’s operating costs off the landlord and onto you, which is why the base rent on a NNN deal is usually lower than on other commercial lease types. You’ll see these leases most often on single-tenant properties like freestanding retail stores, pharmacies, and industrial buildings, but multi-tenant office and retail centers use them too.
What the Three Nets Cover
Each “N” stands for a category of property expense you take on beyond base rent.
- Property taxes. You pay a share of the real estate taxes the local government assesses on the property. These fluctuate year to year as assessors revalue the property, so the obligation is predictable but the dollar amount is not.
- Building insurance. You contribute toward the premiums for insuring the building’s structure against fire, storms, liability claims, and similar risks. The landlord arranges the policy; you reimburse the cost.
- Common area maintenance (CAM). You pay into the upkeep of shared spaces: landscaping, parking lot repairs, snow removal, shared utilities, cleaning for lobbies and restrooms. In a single-tenant building, CAM may be minimal. In a multi-tenant property, it can be substantial.
These three charges are typically billed monthly as estimates alongside your base rent. At the end of each year, the landlord reconciles the estimates against actual expenses and issues either a credit or an additional charge. Read the annual reconciliation carefully. Overcharges here are more common than most tenants realize.
How Your Share of Expenses Gets Calculated
In a multi-tenant building, your share is based on your pro-rata percentage of the total leasable space. Divide your leased square footage by the building’s total rentable square footage, then multiply by 100. Lease 3,000 square feet in a 30,000-square-foot building and your pro-rata share is 10%. You pay 10% of every property tax bill, insurance premium, and CAM charge.
The denominator matters more than most tenants appreciate. If your lease uses gross leasable area (all leasable space, including vacant units), your percentage stays smaller. If it uses only occupied space, a half-empty building can push a much larger share of expenses onto you than you expected. Check how your lease defines that number before you sign.
What You Pay For and What the Landlord Pays For
Beyond the three nets, you handle most day-to-day costs for your own space. You pay your utilities (electricity, water, gas), cover interior repairs like plumbing and electrical work, and maintain any equipment inside your unit. Most NNN leases also require you to keep a full-service HVAC maintenance contract in force throughout the term and provide a copy to the landlord. If that contract lapses and the HVAC fails, you may end up paying for a full replacement even if the system was already aging when you moved in.
Landlord responsibilities in a standard NNN lease center on the building’s structural bones: roof, foundation, exterior walls, and any building-wide systems like a central HVAC plant. Landlords also typically cover major capital expenditures such as repaving a full parking lot or replacing the roof. Every lease draws these lines differently, though. Some push more onto the tenant; others keep more with the landlord. The document controls, so treat the general convention as a starting point rather than a rule.
Roof and Structural Repairs
Roof responsibility is one of the most contested items in NNN negotiations. Some agreements make the tenant responsible for all roof costs. Others split it: the tenant handles routine maintenance and minor patches, and the landlord covers full replacements above a dollar threshold. Asking for an annual cap on tenant roof expenses, or a landlord obligation for replacements above a set cost, is common and reasonable.
HVAC Obligations
A landlord-favorable lease will require you to maintain a service contract with a landlord-approved contractor, keep a maintenance log on-site, and make the log available for review. A more tenant-favorable arrangement keeps the service contract on you but shifts the cost of major component replacements to the landlord as long as you’ve kept up with maintenance. A commercial HVAC replacement can easily run into five figures, so this distinction is worth negotiating.
Insurance You Carry on Your Own
Contributing to the landlord’s building insurance is only part of the picture. Most NNN leases also require you to carry your own policies, and the landlord will want proof before you take possession.
At minimum, expect to need commercial general liability insurance covering bodily injury and property damage claims from third parties, the classic example being a customer who slips and falls in your space. Many leases require at least $1 million in coverage. You’ll also need commercial property insurance for your own business assets: equipment, inventory, furniture, electronics. The landlord’s building policy covers the structure; your policy covers everything inside it that belongs to you.
Landlords routinely require you to name them as an additional insured on your liability policy and to provide a certificate of insurance. A lapse in coverage, even briefly, is usually a lease default. Set up automatic renewals and calendar your proof-of-insurance deadlines.
How NNN Leases Compare to Other Commercial Leases
The NNN lease sits at one end of a spectrum. At the other end is the gross lease, sometimes called a full-service lease, where you pay one flat rent and the landlord covers taxes, insurance, and maintenance out of that amount. Gross leases are simpler and more predictable, but the base rent is higher because the landlord builds those costs in and adds a margin for uncertainty.
In between, you’ll see several variations:
- Single net (N). You pay base rent plus one operating expense category, usually property taxes.
- Double net (NN). You pay base rent plus two categories, typically property taxes and insurance. The landlord keeps maintenance.
- Modified gross. The landlord and tenant split operating expenses in a custom arrangement. You might pay taxes and insurance while the landlord handles CAM, or share all three at negotiated percentages. The specifics vary by contract.
Labels are shorthand. Two leases both called “triple net” can allocate expenses very differently. Read the expense provisions line by line rather than trusting the name on the document.
Absolute Net Leases Are a Separate Animal
An absolute net lease, sometimes called a bondable lease, goes further than a standard NNN. You take on every property expense without exception, including structural repairs and full replacements of the roof, foundation, and building systems. If the roof collapses, that’s your bill. There is essentially no scenario in which the landlord reaches for a checkbook.
These leases exist primarily in sale-leaseback deals with investment-grade tenants like national pharmacy chains and fast-food franchises, where the tenant already treats the building as its own. For a small business, signing an absolute net lease is rarely a good idea. A standard NNN lease, where the landlord keeps structural responsibility, is a much safer arrangement.
Lease Length and Rent Escalation
NNN leases run long. Initial terms of 10 to 25 years are common, especially for single-tenant properties, though shorter terms exist for smaller tenants or multi-tenant buildings. Many leases include built-in renewal options in five- or ten-year increments, exercisable at your discretion.
Rent does not stay flat across that time. Nearly every NNN lease includes an escalation clause. The most common approaches:
- Fixed increases. A set dollar amount or percentage, often 2% to 3%, added annually. This is the most predictable option for both sides.
- CPI-linked increases. Rent adjusts based on the Consumer Price Index published by the Bureau of Labor Statistics, tying rent to actual inflation.
- Market-rate resets. Rent resets to fair market value at set intervals based on comparable properties. More uncertain, but potentially helpful if the market softens.
- Step-up schedules. Rent jumps by predetermined amounts at set points, such as every five years.
Some leases combine methods, like fixed annual increases plus a market reset at renewal. The escalation clause is one of the most important financial terms in the lease because it determines your total occupancy cost over a decade or more.
Protections Worth Negotiating
NNN expenses are not fixed, and tenants who don’t negotiate protections can face steep year-over-year increases. A few provisions do the most work.
Expense Caps
A cap limits how much controllable operating expenses can rise in a year, usually expressed as a percentage above a base-year amount. A 5% annual cap means that even if CAM costs jump 15% one year, your share only goes up 5% over the prior year’s figure. Caps typically apply to controllable expenses like landscaping and janitorial services, not to property taxes or insurance premiums, which are set by outside parties. Whether you can get a cap depends on your leverage, but asking should be standard.
Audit Rights
An audit clause gives you the right to inspect the landlord’s books and verify the operating expenses you’re reimbursing. Accounting errors, misallocated costs from other properties, and charges for items that shouldn’t be passed through all show up regularly in CAM reconciliations. A good audit clause sets a window (often 60 to 120 days after you receive the annual reconciliation) in which you can request an audit, requires the landlord to keep financial records for two to three years, and establishes a dispute process. Miss the audit deadline and most leases treat your silence as acceptance, so calendar it.
Assignment, Subletting, and Early Termination
Most NNN leases prohibit assignment (transferring the entire lease) and subletting (renting space to a subtenant while you stay on the lease) without the landlord’s prior written consent. The standard for that consent is the key negotiation point. Landlord-friendly language lets the landlord refuse “in its sole discretion.” Tenant-friendly language says consent “cannot be unreasonably withheld, conditioned, or delayed.” Even after an assignment goes through, most landlords keep the original tenant on the hook if the new tenant defaults, unless you negotiate a release tied to the assignee meeting financial benchmarks.
Many commercial leases have no pre-negotiated early termination right at all. If the lease is silent, walking away means breaking the contract and facing a claim for the remaining rent, potentially years’ worth. When termination clauses are negotiated upfront, the landlord typically wants three to six months of rent as a termination fee plus reimbursement of unamortized costs such as broker commissions or tenant improvement allowances, with 90 to 180 days’ notice. If there’s any chance your situation could change, negotiate a termination option before you sign, not after.
Personal Guarantees
If your business is an LLC or corporation, the landlord will often ask you to personally guarantee the lease. That means the landlord can pursue your personal assets, including savings, investments, and in some cases your home, if the business can’t pay. It punches through the liability protection your entity would otherwise provide, at least for this obligation.
Newer businesses may not be able to avoid a guarantee entirely, but the terms are negotiable:
- Cap the guarantee at a fixed dollar figure or a set number of months’ rent (six to twelve months is a reasonable ask) rather than the full lease value.
- Include a burn-off provision where the guarantee decreases or expires after a set number of on-time payments or years of occupancy.
- Require the landlord to make reasonable efforts to re-lease the space before coming after you personally.
- Keep the language limited to specific obligations. A guarantee drafted as a broader “indemnity” can expose you to costs well beyond unpaid rent.
Selling your ownership stake or resigning as an officer does not automatically release you from a personal guarantee. You need a formal written release from the landlord, and landlords rarely give one unless a qualified replacement guarantor steps in.
Tax Treatment of NNN Payments
If you’re leasing the property for business use, the rent and the NNN expenses you reimburse are generally deductible as ordinary business expenses. Federal tax law allows a deduction for “rentals or other payments required to be made as a condition to the continued use or possession” of property used in your trade or business, which covers the operating expense reimbursements that make up NNN charges.1Office of the Law Revision Counsel. 26 USC 162 – Trade or Business Expenses Rent is deductible when the property is used for business and the arrangement is a true lease rather than a disguised purchase; prepaid rent must be spread across the period it covers.2Internal Revenue Service. Small Business Rent Expenses May Be Tax Deductible Property taxes you reimburse through NNN charges and business-related insurance premiums are also deductible.3Internal Revenue Service. IRS Publication 535 – Business Expenses
If the Building Is Sold During Your Lease
NNN properties are popular investments, so the building you occupy may change hands during your tenancy. Your lease survives the sale. A new owner takes the property subject to existing lease terms and must honor your agreement as written. Rent, expense allocation, and renewal options do not change just because ownership does.
Before the sale closes, the buyer will usually ask you to sign an estoppel certificate confirming the current status of your lease: rent is current, no disputes are pending, terms are as stated. Review it carefully, because you’re locking in whatever it says. If you have unresolved maintenance requests, pending expense disputes, or any claim against the current landlord, note them on the certificate or resolve them before the sale closes. Anything you fail to raise may be difficult to raise with the new owner later.