What Is an NNN Lease

An NNN lease, short for triple net lease, is a specific type of commercial lease where the tenant, rather than the landlord, is responsible for the three major categories of property operating expense, property taxes, building insurance, and common area or structural maintenance, in addition to paying base rent. This differs from a gross lease, where the landlord typically covers these costs and builds them into a higher base rent, and it differs from a modified gross lease, where expenses are shared according to specific negotiated terms. San Francisco, CA investors evaluating a commercial lease agreement need to read the actual document closely, since the label a listing uses does not always match the lease's real terms.

Breaking Down the Three Nets

The first net generally covers property taxes, meaning the tenant reimburses or directly pays the property tax bill rather than the landlord absorbing it within rent. The second net generally covers building insurance, with the tenant paying for or reimbursing the landlord for casualty and liability coverage on the property. The third net generally covers maintenance, which can include common area upkeep, landscaping, and, in a true triple net structure, responsibility for major building systems, and sometimes roof and structure, though this last item varies significantly by lease and is one of the most important details for a San Francisco, CA investor to confirm before assuming a property is fully passive.

Why the Distinction Matters for an Investor

A property advertised as NNN but where the landlord retains responsibility for roof and structure carries meaningfully more ongoing risk and potential expense than a true triple net lease where the tenant covers everything. This distinction directly affects the property's suitability as a passive 1031 exchange replacement property, since an investor moving from active property management into what they expect to be a passive NNN asset needs the lease to actually deliver that passivity. We review the specific lease document, not just the listing description, with San Francisco, CA investors before they identify an NNN property during their exchange, so expectations match the actual legal obligations in the lease.

Rent escalation clauses, renewal option terms, and any landlord responsibilities that survive despite the triple net label all affect the property's long term value and risk. We help investors understand these lease mechanics in plain terms, coordinate a full lease review with the investor's attorney, and confirm how a specific NNN property's terms compare to a true triple net structure before the investor commits to it as replacement property within their exchange timeline.