A triple-net lease is a structure in which the tenant pays base rent plus substantially all of the property's operating costs (real estate taxes, building insurance premiums, and structural maintenance) directly, removing those expenses from the landlord's cash flow statement. Because the landlord receives base rent largely unencumbered by operating cost exposure, the net income stream is highly predictable and requires minimal management involvement.
That predictability comes at a price: NNN base rents are set below the all-in rent a tenant would pay in an equivalent gross lease building, because the tenant is bearing costs that would otherwise be embedded in a higher gross rent. The underwriting question is always whether the lower base rent, when combined with the landlord's freedom from expense risk, produces a superior risk-adjusted outcome relative to a gross lease alternative.
Rent escalation provisions determine the long-run income trajectory of a NNN asset and are negotiated with as much care as the base rent itself. Fixed-bump escalations, typically 1.5% to 3.0% annually or 10% every five years, are the most common structure in single-tenant NNN retail.
They offer predictable compounding but erode real purchasing power in high-inflation environments: a 2% fixed bump against 5% CPI inflation means the landlord's real income falls every year of the lease. CPI-linked escalations directly hedge inflation exposure but introduce variability that can complicate lender underwriting and cap rate valuation, since a floating income stream is harder to capitalize at a single rate.
Some longer-term NNN leases use hybrid structures, such as a fixed floor with a CPI ceiling, to balance tenant covenant simplicity against landlord inflation protection.
A rigorous total return comparison between NNN and gross lease alternatives requires modelling the full 10-year cash flow, not just the going-in cap rate. A NNN property trading at a 5.5% cap with 2% annual bumps will be generating roughly $1.22 for every $1.00 of initial NOI by year ten.
A comparable gross lease property at a 6.5% cap but with strong operating expense growth (taxes increasing 4% annually, insurance spiking after a loss event) may see net NOI grow more slowly than the spread in cap rates implies. The landlord of a gross lease building also bears the asymmetric risk of insurance market hardening or municipal tax reassessments that can compress NOI without any corresponding adjustment to the lease term.
Over a full cycle, operating expense discipline and escalation mechanics often matter more than the nominal spread between NNN and gross cap rates.
Long-duration NNN assets (leases of 15 to 20 years with creditworthy single tenants) trade with bond-like characteristics that create significant interest rate sensitivity. When the risk-free rate rises, the discount rate applied to the long, predictable income stream increases, reducing the present value of those cash flows.
A 100-basis-point increase in the discount rate applied to a 20-year NNN income stream can reduce the asset's present value by 8% to 12%, depending on the escalation schedule and terminal cap rate assumption, an exposure comparable to a medium-duration fixed-income instrument. Short-lease NNN assets retain more optionality: the ability to re-price the rent at rollover gives the landlord a natural hedge against inflation and a reset mechanism if market rates move.
Investors valuing long-duration NNN assets for income stability should model their interest rate sensitivity explicitly and stress-test the hold-period return against both cap rate expansion and escalation shortfall scenarios.