A triple net lease is a commercial lease in which the tenant pays property taxes, building insurance, and maintenance costs on top of the base rent. It is abbreviated NNN, and the three Ns are those three expense categories. The headline rent on an NNN lease always looks cheap compared with a gross lease, because it is only part of what you will actually pay. This guide explains what each net covers, how a triple net lease compares with gross and modified gross alternatives, and the specific terms worth checking before you sign one.
The short version
NNN stands for the three nets: property taxes, insurance, and common area maintenance. On a triple net lease you pay all three on top of base rent, usually as a monthly estimate that is reconciled against actual costs each year. Always ask for the current NNN figure per square foot, not just the base rent.
A triple net lease (NNN lease) is a commercial lease under which the tenant pays base rent plus a proportionate share of property taxes, building insurance, and common area maintenance.
What NNN Means in Real Estate
The three Ns are three categories of expense that shift from landlord to tenant. Each is normally charged as your proportionate share, based on the square footage you occupy relative to the whole building.
- Net one — property taxes. Your share of the real estate taxes assessed on the building. These can rise on reassessment, often after the property is sold.
- Net two — building insurance. The landlord’s property insurance premium, not your own liability or contents cover, which you still need separately.
- Net three — common area maintenance (CAM). Upkeep of shared parts of the property: parking, landscaping, lighting, snow removal, security, and management fees.
In practice you pay a monthly estimate alongside rent, and the landlord reconciles it against actual spend after year end. If actual costs exceeded the estimate, you get a bill. That reconciliation is the part tenants most often fail to plan for.
The Third Net: Where the Variability Lives
Taxes and insurance are externally set and hard to dispute. CAM is discretionary, controlled by the landlord, and where the real variability lives.
Three questions decide whether it is reasonable — each covered in full in our guide to CAM charges and how to cap them:
- Is there a cap? Ask for an annual cap on controllable CAM — typically 3 to 5 percent. Taxes and insurance are usually excluded from any cap because the landlord cannot control them.
- Are capital improvements included? A new roof or resurfaced parking lot is a capital expense, not maintenance. If capital items can be passed through, ask that they be amortised over their useful life rather than billed in one year.
- Can you audit it? An audit right lets you inspect the landlord’s books behind the reconciliation. Ask for a window of at least 90 days after the statement arrives.
Also check the administrative fee. Many leases add a management or admin charge of 10 to 15 percent on top of CAM. That is negotiable, and it is worth knowing whether it is calculated on CAM alone or on CAM plus taxes and insurance — the difference is meaningful over a multi-year term.
Triple Net Lease vs Gross Lease and Modified Gross
The lease types differ in one respect only: who carries the operating expenses.
- Gross lease (full service). One rent figure covers everything. The landlord pays taxes, insurance, and maintenance out of the rent. Simplest for a tenant to budget, and typically the highest headline number.
- Modified gross lease. A split. The tenant may pay utilities and interior upkeep while the landlord keeps taxes and insurance, or costs are shared above a base year figure. Terms vary widely, so read rather than assume.
- Triple net lease. The tenant pays base rent plus all three nets. Lowest headline rent, highest variability.
The practical consequence is that quoted rents across lease types are not comparable. A gross lease at $30 per square foot and an NNN lease at $22 plus $9 of nets are not an $8 difference — the NNN space is more expensive, and its cost can move each year while the gross figure cannot. Always compare the fully loaded number.
Single, Double, and Absolute Net Leases
Triple net sits inside a family of net lease structures that differ by how many expense categories transfer:
- Single net (N). Tenant pays base rent plus property taxes.
- Double net (NN). Tenant pays rent plus taxes and insurance. Landlord retains structural and common area maintenance.
- Triple net (NNN). Tenant pays rent plus taxes, insurance, and maintenance.
- Absolute net (bondable). Tenant carries everything, including roof, structure, and rebuilding after casualty. Most common with single-tenant buildings and creditworthy national tenants.
The distinction that matters most to a small business is whether roof and structure are yours. Many leases described casually as triple net are in fact absolute net for those items. A roof replacement on a building you do not own is not a maintenance expense you should discover mid-term.
How a Triple Net Lease Works in Practice
A worked example makes the arithmetic concrete. Suppose you lease 2,000 square feet in a 20,000 square foot building, so your proportionate share is 10 percent.
- Base rent quoted at $22 per square foot: 2,000 × $22 = $44,000 per year
- Building taxes of $60,000, your 10 percent share: $6,000
- Building insurance of $20,000, your share: $2,000
- CAM of $100,000, your share: $10,000
Total annual cost is $62,000, or $31 per square foot — not the $22 in the listing. The nets added roughly 41 percent. That is why the only number worth comparing between spaces is base rent plus estimated nets, and why you should ask for the last two years of actual reconciliations rather than the landlord’s estimate alone. Estimates are optimistic; reconciliations are history.
What to Check Before Signing a Triple Net Lease
- Ask for two years of actual CAM reconciliations. The single most informative document in the negotiation.
- Cap controllable CAM at a fixed annual percentage, and exclude capital improvements or require amortisation.
- Confirm roof and structure. Get it in writing that they are the landlord’s responsibility unless you intend otherwise.
- Check the proportionate share calculation. Is it based on leasable or leased square footage? If vacancies are excluded, your share rises when the building empties.
- Negotiate an audit right with a reasonable window after each annual statement.
- Check the admin fee and what base it is applied to.
Point four is the one that catches people. A proportionate share calculated on occupied rather than total square footage means that as neighbouring tenants leave, your share of unchanged building costs increases — you pay more for the same space because the landlord has fewer tenants to spread costs across. Ask for the denominator to be total leasable area.
Because a lease is governed almost entirely by its own written terms, the Legal Information Institute is a useful primer on how leasehold obligations are construed. Commercial tenants receive far fewer statutory protections than residential ones, so what you negotiate is what you get. The broader set of terms worth scrutinising is covered in our guide to commercial lease negotiation.
ContractClerk reviews commercial leases including NNN structures, flags uncapped CAM pass-throughs and proportionate-share definitions that shift risk to the tenant, and explains each in plain English before you sign.
NNN stands for the three nets a tenant pays on top of base rent: property taxes, building insurance, and common area maintenance. A lease advertised as NNN quotes only the base rent, so the true occupancy cost is that figure plus the estimated nets per square foot.
The tenant does, as a proportionate share based on the square footage occupied. The landlord receives the tax bill and passes the share through, usually as part of a monthly estimate reconciled annually. Taxes can jump after a property is sold and reassessed.
The base rent is lower, but the total cost usually is not. A gross lease bundles operating expenses into one fixed figure, while an NNN lease adds them separately and lets them vary each year. Compare base rent plus estimated nets, never the headline rents alone.
A double net lease has the tenant pay base rent plus property taxes and insurance, with the landlord retaining maintenance. A triple net lease adds common area maintenance to the tenant’s obligations. Absolute net goes further still, transferring roof, structure, and casualty rebuilding.
Yes, and usually every year. You pay a monthly estimate that is reconciled against actual spend after year end, so an underestimate produces a bill. Negotiate an annual cap on controllable CAM, exclude capital improvements, and secure an audit right over the reconciliation.
The Bottom Line on Triple Net Leases
A triple net lease is not a worse deal than a gross lease — it is a less predictable one, and it moves the risk of rising operating costs onto you. Handled well, with capped CAM, a fair proportionate share, and an audit right, it is perfectly workable. Handled by reading only the base rent, it produces an annual reconciliation bill nobody budgeted for. Ask for the last two years of actuals before you sign anything.
This article is general information, not legal advice, and does not create an attorney-client relationship. Contract and property law vary by state and by situation. For a commercial lease, have a licensed attorney review the document.