A triple net lease (NNN) is a commercial lease in which the tenant pays base rent plus its proportionate share of three property costs — property taxes, building insurance, and common area maintenance — on top of that rent. It is the dominant structure in US retail, and it is the single most common reason a space that looked affordable in a listing turns out to cost thirty or forty percent more than the tenant modeled.
The mechanics are not complicated. The discipline is. A NNN quote unbundles occupancy cost into a low, attractive headline number and a set of variable charges that are easy to skim past, hard to forecast, and reconciled after the fact. This guide covers what the three nets are, what the landlord still pays, how to calculate your all-in cost, and the specific clauses worth auditing before you sign.
In a triple net lease the tenant pays base rent + taxes + insurance + CAM. The landlord typically keeps the roof, structure, and foundation. Your real number is the all-in dollars per square foot per year, which in many retail deals runs 25–40% above the quoted base rent. Never compare a NNN quote to a gross quote without converting both to all-in, and never sign a NNN deal without knowing the CAM history, the caps, and the admin fee. Terms vary by lease and jurisdiction.
What Does a Triple Net Lease Mean?
Triple net means three categories of property operating cost are “netted out” of the rent and billed to the tenant separately. The landlord collects a base rent that is net of taxes, net of insurance, and net of maintenance — hence three nets, written NNN. The tenant pays its pro rata share, usually calculated as its square footage divided by the leasable square footage of the center.
That pro rata calculation matters more than most tenants realize. If the denominator is gross leasable area rather than occupied area, a half-empty center can hand you a share of costs for space nobody is paying for. Ask which denominator the lease uses and whether vacancy is grossed up.
The three nets, one at a time
- Property taxes. Your share of the real estate taxes assessed on the property. This is the net most likely to jump, because a sale or a reassessment can reset the assessed value sharply in a single cycle.
- Building insurance.Your share of the landlord’s property and liability coverage on the building and common areas. It does not replace your own general liability and contents policies, which the lease will separately require you to carry.
- Common area maintenance (CAM). The widest and most negotiable of the three: parking lot repair and striping, lot lighting, landscaping, snow removal, security, trash, shared utilities, property management, and frequently an administrative fee layered on top.
What Does the Landlord Pay in a Triple Net Lease?
In most retail NNN leases the landlord retains the roof, the structure, the foundation, and typically the exterior walls, along with its own mortgage, income taxes, and capital costs of ownership. The tenant takes the operating layer; the landlord keeps the asset layer. That is the general practice, not a universal rule — the allocation is a negotiated term and varies by lease and jurisdiction.
The friction lives at the boundary between repair and replacement. A landlord who is responsible for the roof may still push the cost of “roof maintenance” into CAM, and a parking lot resurfacing can be characterized as either routine upkeep (tenant) or a capital improvement (landlord) depending on how the lease is drafted. Get capital expenditures excluded from CAM, or at minimum required to be amortized over their useful life rather than expensed in the year incurred.
A true “absolute net” or bondable lease pushes everything to the tenant, including roof and structure, and is most common in single-tenant freestanding deals. If you are signing a freestanding building, confirm which of the two you are actually being handed — the word “net” on a term sheet does not tell you.
What Is a Gross Lease vs. a Triple Net Lease?
A gross lease bundles operating costs into one rent the landlord absorbs; a triple net lease unbundles them and bills them to the tenant. Modified gross sits between the two, typically with the landlord covering costs up to a base-year or expense-stop amount and the tenant paying increases above it. The practical consequence is that a $34 NNN quote and a $46 gross quote can be the same deal.
| Structure | Tenant pays | Landlord pays | Cost predictability |
|---|---|---|---|
| Gross (full service) | One all-inclusive rent | Taxes, insurance, CAM, structure | Highest — fixed, but priced with a risk premium |
| Modified gross | Base rent plus increases above a base year or expense stop | Operating costs up to the stop, plus structure | Moderate — depends entirely on how the base year is set |
| Triple net (NNN) | Base rent plus pro rata taxes, insurance and CAM | Roof, structure, foundation (typically) | Lowest — nets float and reconcile annually |
| Absolute net / bondable | Essentially all property costs, including roof and structure | Financing and ownership costs only | Lowest — tenant carries capital risk |
The rule for comparing offers: convert every quote to all-in dollars per square foot per year before you rank them. A NNN quote looks cheap next to a gross quote for the same reason a fare looks cheap before taxes and bags. Neither number is dishonest; they are simply not the same unit.
How Do You Calculate a Triple Net Lease?
Add the three net charges to the base rent to get an all-in rate per square foot per year, then multiply by your square footage for the annual number and divide by twelve for the monthly one. A 2,400 sf space at $34 base with $5.50 taxes, $1.25 insurance and $6.00 CAM is $46.75 all-in, or $112,200 a year — roughly $9,350 a month, of which about 27% is not base rent at all.
Enter your own numbers below. Change the square footage and the three nets, then switch on the projection to see what a few points of annual escalation on the nets does to your year-five cost. The share that is not base rent is the figure worth writing down.
Read it this way: the quoted base rent is only part of the bill. The fourth number is the share of your occupancy cost that comes from taxes, insurance and CAM — the portion tenants routinely leave out of a pro forma.
Then turn it into an occupancy cost ratio
The all-in dollar figure is only half an answer. Divide projected annual occupancy cost by projected annual sales for that specific location and you get the occupancy cost ratio, which is the number that actually determines whether the unit works. Target ratios differ sharply by concept — a quick-service restaurant, a fitness studio and an apparel shop do not carry rent the same way — and the exercise is worked through in detail in our guide to percentage rent and occupancy cost.
What to Audit Before You Sign
Most NNN surprises are written into the lease before the tenant ever gets an invoice. Four items deserve direct attention during negotiation, not after.
CAM caps
Ask for a cap on annual CAM increases, and read carefully whether it is cumulative or non-cumulative and whether it is compounding. A non-cumulative cap resets each year and protects you far better than a cumulative one that lets a landlord bank unused headroom. Controllable expenses are the realistic target for a cap; taxes and insurance are usually carved out because the landlord cannot control them.
Base-year games
In modified gross and expense-stop structures, the base year sets your floor for the life of the deal. A base year computed during a period of unusually low expenses, or on a partially vacant building, means you start paying increases immediately. Insist on a grossed-up base year that reflects a fully occupied property.
Administrative fees
Many leases add an administrative or management fee as a percentage on top of CAM. Confirm the percentage, confirm what it is calculated on, and push to exclude taxes, insurance, and capital items from the base it applies to — otherwise you pay a management fee on a tax bill nobody managed.
Audit rights and history
- Request three years of actual CAM and tax reconciliations for the property, not an estimate.
- Negotiate a written right to audit the landlord’s books, with a reasonable window after reconciliation.
- Get exclusions in writing: capital improvements, leasing commissions, landlord marketing of vacant space, and costs recovered from other tenants or from insurance.
- Confirm how the pro rata denominator is defined and whether vacancy is grossed up.
- Check for an anchor kick-out or co-tenancy interaction — CAM per tenant rises when a center loses occupancy.
Co-tenancy risk and CAM risk are the same risk viewed from two angles, which is why anchor tenant and co-tenancy clauses belong in the same conversation as your NNN estimate.
The All-In Number Only Matters Relative to Revenue
A $46 all-in rate is cheap in a location that will do $1.4M and ruinous in one that will do $600K. Tenants spend weeks negotiating a dollar off base rent and minutes on the sales forecast that determines whether the dollar matters. The rent conversation and the revenue conversation are one conversation.
That is the part Locate is built around: forecasting what a specific site will actually produce, then negotiating the lease against that number rather than against a comp. Pair this with our work on new store sales forecasting and moving from LOI to signed lease, and if you want a second read on a deal in front of you, get in touch.
One last note on sourcing your own market read: demand signals are increasingly visible before a store exists. Semrush’s research on search volume puts US “near me” queries at roughly 7.1 million a month and up 29% year over year, with city-level volume available across its keyword database. That is a useful cross-check on whether the trade area behind an expensive NNN deal is actually growing.
Lease terms vary by document and by jurisdiction. Treat everything here as general practice and have counsel review the actual language before you sign.
Common Questions
- What is a triple net lease?
- A triple net lease is a commercial lease in which the tenant pays base rent plus its proportionate share of three operating costs of the property: property taxes, building insurance, and common area maintenance. Those three pass-through charges are the “nets,” usually quoted separately in dollars per square foot per year. The structure is standard in US retail, particularly in shopping centers and freestanding buildings, though the exact allocation always depends on the lease document.
- What does triple net lease mean for a tenant's monthly bill?
- It means the quoted rent is not the bill. A tenant in a triple net lease pays base rent plus monthly estimated NNN charges, and then settles up at year end when the landlord reconciles actual taxes, insurance, and CAM against what was collected. Budget for the all-in number, not the base rent, and budget for a reconciliation invoice that can arrive months after the year closes.
- What does the landlord pay in a triple net lease?
- Typically the landlord retains responsibility for the roof, the structure, the foundation, and often the exterior walls, plus its own financing, income taxes, and capital costs of ownership. Most well-negotiated retail leases keep structural repair and replacement with the landlord while operating-level maintenance passes to tenants. This split is a negotiated term, not a legal default, and it varies by lease and jurisdiction, so read the maintenance and repair clauses rather than assuming.
- What is included in a triple net lease?
- The three nets are property taxes, building insurance, and common area maintenance. CAM is the widest of the three and commonly covers parking lot upkeep, lighting, landscaping, snow removal, security, trash, and shared utilities, and in many leases an administrative fee on top. Tenants also separately pay their own in-premises utilities, interior maintenance, and often HVAC service, which are not technically part of the three nets.
- What is a gross lease versus triple net?
- In a gross lease the landlord absorbs operating costs and the tenant pays one all-inclusive rent; in a triple net lease those costs are unbundled and billed to the tenant on top of a lower base rent. A gross quote is therefore usually higher and more predictable, and a NNN quote lower and more variable. Compare them only on an all-in dollars-per-square-foot basis, because the headline numbers are not measuring the same thing.