Single Net Lease Explained: N Lease Costs and CAM Risk
Quick Answer
A single net lease (N lease) has the tenant paying base rent plus property taxes only. The landlord covers insurance, CAM, maintenance, and structural costs. Single-net is the rarest net lease type because it creates an awkward risk split and has been largely displaced by NN and NNN structures.
If you encounter a single-net lease in a due diligence file or an older property you are taking over, it is almost certainly a legacy document. Here is what it means, how it works, and why you will not see many new ones being written today.
What the Single Net Lease Actually Means
The "single" in single-net refers to one expense category that the tenant takes on: property taxes. That is it.
| Expense Category | Tenant's Obligation | Landlord's Obligation |
|---|---|---|
| Base rent | Yes | - |
| Property taxes | Yes | - |
| Building insurance | No | Yes |
| CAM (maintenance, landscaping, janitorial) | No | Yes |
| Structural repairs | No | Yes |
| HVAC maintenance and replacement | No | Yes |
| Utilities (common areas) | No | Yes |
| Management fees | No | Yes (absorbed) |
The landlord pays for everything except property taxes. Under a 50,000 SF building with $1.80/SF in insurance costs and $4.20/SF in operating/maintenance costs, the landlord is absorbing $300,000/year in costs while passing through only the tax line.
Why the Risk Split Is Awkward
Property taxes are the most volatile of the three major operating expense categories. They are driven by government assessment decisions, market value appreciation, and political tax policy, all completely outside the landlord's control. Insurance and CAM, while they can increase, are partially within the landlord's management influence.
Single-net creates a situation where:
- The landlord absorbs predictable-but-rising maintenance costs
- The landlord absorbs insurance costs (which have been highly volatile since 2022)
- The tenant absorbs tax increases that neither party can control or predict
This is backwards from a risk management perspective. NNN leases pass all three categories to tenants, creating cleaner incentive alignment. Gross leases price everything in, creating cost certainty. Single-net does neither. It creates an ambiguous middle ground where the landlord has expense exposure without the simplicity of a gross structure.
Comparing N, NN, and NNN Side-by-Side
| Feature | Single-Net (N) | Double-Net (NN) | Triple-Net (NNN) |
|---|---|---|---|
| Tenant pays: taxes | Yes | Yes | Yes |
| Tenant pays: insurance | No | Yes | Yes |
| Tenant pays: CAM | No | No | Yes |
| Landlord exposure | High | Moderate | Low |
| CAM reconciliation | No | No | Yes |
| Modern prevalence | Rare | Uncommon | Dominant (retail/industrial) |
For the double-net comparison, see double net lease explained. For the NNN deep dive, see NNN lease vs gross lease.
How Property Tax Billing Works Under Single-Net
The mechanics are the same as any net lease tax allocation:
- Landlord receives the annual property tax bill (timing varies by municipality, typically Q3 or Q4)
- In multi-tenant buildings, the bill is allocated by pro-rata share (tenant SF / total building SF x annual tax)
- The landlord bills the tenant their proportionate share, either as a monthly estimate collected throughout the year, or as a lump sum after receiving the actual bill
- Year-end reconciliation adjusts for any difference between estimates and actuals
Worked example: Building with 40,000 SF total leasable area. Annual property tax: $168,000 ($4.20/SF). A single-net tenant with 6,000 SF has a 15% pro-rata share: $25,200/year in taxes, billed at $2,100/month.
If the county reassesses the property mid-lease and taxes jump to $5.10/SF, the tenant's obligation increases to $30,600/year with no cap protection. Property taxes are non-controllable regardless of lease type.
Where Single-Net Leases Still Appear
Single-net leases are not extinct. They are concentrated in specific contexts:
Legacy industrial leases: Industrial properties in manufacturing-heavy markets (Midwest, Southeast) often have older leases drafted in the 1980s-1990s with N structures. Renewal negotiations typically push toward NN or NNN.
Ground leases: Ground leases sometimes have the ground tenant (who owns the improvements) pay property taxes while the ground landlord (who owns the land) handles other costs, creating a de facto single-net arrangement.
Very small single-tenant properties: A small freestanding retail building of under 3,000 SF where the landlord knows the tenant personally and wants simplicity may use single-net to avoid the complexity of full NNN billing.
Percentage lease hybrids: Some retail percentage leases combine a low base rent with single-net tax pass-through, keeping the operating structure simple while still participating in tenant revenues.
Converting Single-Net to a Standard Lease Structure
If you are managing a portfolio with single-net leases and working toward standardization, the conversion to NNN or modified-gross typically happens at lease renewal. The considerations:
Establish baseline expense data. Before transitioning a tenant to NNN, you need historical expense records to set realistic CAM estimates. If the landlord has been absorbing all CAM costs without detailed tracking, there may be a gap in the data needed to set first-year NNN estimates.
Assess tenant negotiating position. In high-vacancy markets, tenants may resist moving from N to NNN because adding $4-$6/SF in CAM obligations on top of their existing tax obligation changes the economics. Landlords may need to reduce base rent to offset.
Review the existing lease for conversion provisions. Some older leases include clauses addressing what happens at renewal with respect to lease structure. These provisions can either facilitate or complicate conversion.
For the full context of how single-net fits within commercial lease structures, see the commercial lease types guide, the commercial lease rent structures overview, and gross lease vs net lease.
The Bottom Line on Single-Net Leases
Single-net leases are a relic of an era when CRE transactions were less sophisticated and expense allocation conventions had not standardized around NNN. They persist in legacy portfolios and specific niche situations, but new single-net leases are uncommon.
If you are underwriting a property with single-net tenants, model the landlord's ongoing CAM and insurance exposure carefully. Those costs will grow regardless of what the tenant pays, and there is no recovery mechanism until the lease renews. The cam variance analysis framework helps quantify that exposure even when it is not a billable reconciliation item.
For NNN investment property analysis and how to evaluate properties with mixed lease structures, see those guides next.
Sources
- Cornell Law School Wex - Net Lease
- LoopNet - Single Net Leases: Costs, Benefits, and Risks for Property Owners
- LegalClarity - What Does Triple Net Mean in Real Estate?
Frequently asked questions
What is a single net lease?
A single net lease (also called an N lease) is a commercial lease where the tenant pays base rent plus property taxes. The landlord retains responsibility for building insurance, all common area maintenance (CAM), structural repairs, and other operating costs. The 'single' refers to the one expense category passed to the tenant: property taxes. Single-net leases are the least common of the net lease types, far rarer than double-net (NN) or triple-net (NNN). They appear primarily in older industrial leases, some ground lease arrangements, and legacy retail properties from the 1980s and early 1990s.
Why are single net leases uncommon in modern commercial real estate?
Single-net leases fell out of favor because the expense allocation is awkward for both parties. The landlord retains operating cost exposure (insurance, CAM, maintenance, management) while the tenant takes on property taxes, which are volatile and outside either party's direct control. Landlords do not benefit from the simplicity of a gross lease (where they price in full cost absorption) or the expense recovery of NNN (where costs pass through more completely). The resulting risk profile is a compromise that works poorly for institutional investors. Most properties that started as N leases have converted to NN or NNN at renewal.
How are property taxes billed under a single net lease?
Under a single-net lease, property taxes are typically paid by the landlord who then invoices the tenant for reimbursement, or in single-tenant situations, the tenant may pay the taxing authority directly. In multi-tenant buildings with single-net leases, each tenant's share is calculated as their leasable square footage divided by total building leasable area, multiplied by the annual tax bill. Monthly estimates are collected and reconciled annually when the actual tax bill is received. Successful tax appeals generate credits or refunds that must flow back to tenants in proportion to what they paid. Assessment increases require upward adjustment of monthly estimates.
What is the difference between a single net lease and a double net lease?
The key difference is insurance: double-net (NN) leases pass both property taxes and building insurance to the tenant. Single-net (N) leases pass only property taxes. Insurance stays with the landlord. Under a single-net structure, the landlord also retains CAM, maintenance, and structural responsibility. Double-net leases are more common than single-net because the addition of insurance pass-through gives landlords better cost recovery without requiring a full NNN structure. In practice, the difference in total tenant exposure between N and NN can be $1.00-$2.50/SF depending on building type, size, and insurance market conditions.
Can a single net lease convert to a NNN at renewal?
Yes, landlords frequently attempt to convert legacy single-net or double-net leases to NNN structures at renewal. Whether this is achievable depends on market conditions and the tenant's negotiating position. In landlord-favorable markets (low vacancy, limited alternatives), conversions to NNN are common. In tenant-favorable markets, tenants may resist full NNN terms and negotiate for modified-gross or NN structures instead. The conversion also requires establishing baseline expense data for the first reconciliation period under the new structure, which can create disputes if historical cost records are incomplete. Some leases include automatic structure transitions at renewal through a 'NNN conversion option' clause.